PID

A/D

RAM
F
GLOBAL
SUPPLIERS
OF
TURBINE
ID
AND
COMPRESSOR
CONTROL
SYSTEMS

UM3307 Series 3++ Speed Controller

#
Speed Controller
for Steam Turbines

Publication UM3307 (2.1.0)

Product Version: 1063-005
March 2021

Documentation Feedback Form

COMPRESSOR CONTROLS CORPORATION

Des Moines, Iowa, U.S.A.

Phone: (515) 270-0857

Web: www.cccglobal.com
© 1987-2021, Compressor Controls Corporation. All rights reserved.
This manual is for the use of Compressor Controls Corporation and is
not to be reproduced or redistributed without written permission.
Air Miser, Guardian, Prodigy, Recycle Trip, Reliant, Safety On,
SureLink, TTC, Total Train Control, TrainTools, TrainView, TrainWare,
Vanguard, Vantage, Vibrant, WOIS, and the TTC and impeller logos
are registered trademarks; and COMMAND, TrainPanel, Series 3++
and Series 5 logos, CCC Inside, and CCC Pro Built are trademarks of
Compressor Controls Corporation. Other company and product
names used in this manual are trademarks or registered trademarks
of their respective holders.
The purpose of this document is only to describe how to use CCC’s
products. It is not sufficiently detailed to enable outside parties to du-
plicate or simulate their operation. CCC reserves the right to alter the
designs or specifications of its products at any time and without notice.
Disclaimer: This manual may be translated into another language for
those not fluent in the English language. The English language original
shall prevail for all technical and legal purposes.
 Series 3++ Speed Controller 3

Document Scope
This manual describes the operation, configuration, and tuning of a Series 3++
Speed Controller. It does not tell how to install or maintain it, nor how to program a
DCS or other host to use its computer communication interface.
Chapter 1 summarizes this controller’s applications and features.
Chapter 2 describes the operation and human-machine interface features of
the Speed Controller.
Chapter 3 tells how to configure the analog and discrete inputs and outputs
and serial communication ports.
Chapter 4 tells how to configure the speed profile and inputs.
Chapter 5 tells how to configure the speed and cascade/limiting PID loops and
explains how the control response is selected from their actions.
Chapter 6 describes the operation and configuration of a Speed Controller for
a turbine-driven synchronous electric generator.
Chapter 7 tells how the intended valve position and actuator control signal are
calculated from the speed control response.
Chapter 8 tells how to configure the automatic sequencing and overspeed pro-
tection features.
Appendix A describes each Speed Controller configuration parameter.
Appendix B describes the controller test procedures that can be executed from
the Engineering Panel.
Finally, the following supporting documents are included at the back of this manual:
DS3307/D lists and describes the default data items the Series 3 OPC Server
provides for this controller.
DS3307/M lists this controller’s Modbus coils, discrete inputs, and registers.
DS3307/O describes the controller’s Front-Panel operator interface.
DS3307/V describes the changes in each standard release of this controller.
FM3307/C lists the configuration and tuning parameters by key sequence,
organized by data group and page.
FM3307/L lists the configuration and tuning parameters by name, grouped
according to the associated controller feature.

March 2021 UM3307 (2.1.0)

4 Contents

Document Conventions
Attention may be drawn to information of special importance by
using the following structures:

Note: Notes contain important information that needs to be emphasized.

Caution: Cautions contain instructions that, if not followed, could lead to irre-
versible damage to equipment or loss of data.

Warning! Warnings contain instructions that, if not followed, could lead

to personal injury.

The appearance of this electrical hazard warning symbol on CCC

equipment or the word Warning appearing in this manual indicates
dangerously-high voltages are present inside its enclosure. To
reduce the risk of fire or electrical shock, do not open the enclo-
sure or attempt to access areas where you are not instructed to do
so. Refer all servicing to qualified service personnel.

The appearance of this user caution symbol on CCC equipment or

the word Caution appearing in this manual indicates damage to the
equipment or injury to the operator could occur if operational proce-
dures are not followed. To reduce such risks, follow all procedures
or steps as instructed.

March 2021 UM3307 (2.1.0)

 Series 3++ Speed Controller 5

Table of Contents
Document Scope . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
Document Conventions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
Table of Contents. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
List of Figures. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
List of Tables . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Symbols and Acronyms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
Chapter 1 Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
Applications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
Major Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
Speed Measurement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
Speed Control Loop . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
Cascade/Limiting Control Loop . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
Single Extraction Turbine Control. . . . . . . . . . . . . . . . . . . . . . . . . . 19
Generator Control. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
Overspeed Protection. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
Start-Up and Stop Sequences . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
Automatic or Manual Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
Redundant Controller Tracking . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
Hardware Configurations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
Analog and Discrete I/O . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
High-Current Output . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
Serial Communication . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
Configuration and Tuning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
Chapter 2 Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
Operator Interfaces . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
Continuous Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
Control Element Position . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
Speed and Set Point . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
Local Set Point . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
Remote Set Point . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
Cascade Set Point . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
Speed Alarms. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
Limiting Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
Variable-Speed Load . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
Synchronous Generator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
Isochronous Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
Droop Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
Sequencing Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35
Idle State . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36
Idle Indicators . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36
Ramp to Idle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37
Idling a Generator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37
Ramp to Rated . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38
Critical Speed Stall . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39

March 2021 UM3307 (2.1.0)

6 Contents

Emergency Shutdown . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .39

Ramped Stop. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .40
Generator Shutdown . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .40
Shutdown State . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .41
Ready State . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .41
Turbine Startup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .42
Manual Startup. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .43
Generator Startup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .43
Black Starting. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .43
Manual Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .44
Selecting Manual Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .44
Restoring Automatic . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .45
Tracking State . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .46
Controller Health . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .47
CPU/IO and Auxiliary PCB Faults . . . . . . . . . . . . . . . . . . . . . . . . . .47
Internal Conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .48
Power Supply Failures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .48
Battery Failure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .48
Speed Input Signals. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .49
Speed Input Failures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .49
Analog Input Signals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .49
Transmitter Failures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .49
Analog Output Signals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .49
Output and Valve Position Failures . . . . . . . . . . . . . . . . . . . . . . .50
Discrete I/O Signals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .50
Serial Communication Errors. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .50
Chapter 3 Input/Output Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .53
Hardware Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .53
CPU and Auxiliary PCB Firmware . . . . . . . . . . . . . . . . . . . . . . . . . .54
Disabling Input Signals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .54
Analog Inputs. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .55
Analog-to-Digital Variables . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .56
Transmitter Testing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .56
Signal Variables. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .57
Measured Variables. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .57
Analog Outputs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .59
High-Current Output . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .60
Bipolar Output . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .60
Output Loopback Test . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .61
Standard Analog Outputs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .61
Valve Positioning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .62
Digital Positioning Module . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .63
Discrete Inputs. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .64
Control Functions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .64
Automatic or Manual Operation . . . . . . . . . . . . . . . . . . . . . . . . . .66
Speed Set Point . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .66
Operating State and Sequencing. . . . . . . . . . . . . . . . . . . . . . . . .67

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 Series 3++ Speed Controller 7

Operating Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67
Generator Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68
Overspeed Trip Test . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68
Front-Panel Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68
24 Vdc Power Tests . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68
Control Relays . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69
Fault Relays . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69
External Alarms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69
Relay Assignments. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70
Serial Ports. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 74
ID Numbers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 75
Serial Communication Formats . . . . . . . . . . . . . . . . . . . . . . . . . . . 75
Modbus/OPC Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 75
Redundant Tracking. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 76
Switching Conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 76
Chapter 4 Turbine Speed . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 77
Turbine Speed Profile . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 77
Valid Speed Range . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 78
Control Range . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 78
Normal Operating Range . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 78
Critical Speed Ranges . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 79
Idle and Rated Speeds. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 79
Speed Switches . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 80
Speed Inputs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 81
Scaling and Normalization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 82
MPU Tests . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 83
Chapter 5 Speed Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 85
General PID Algorithm . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 85
Dead Zones . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 85
Speed Control Loop . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 86
Speed Set Point . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 87
Computer Set Point . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 87
Local Set Point . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 87
Serial Remote Set Point . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 88
Analog Remote Set Point . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 88
Cascade Set Point . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 88
Speed Deviation Alarm. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 88
Cascade / Limiting Loop. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 89
Performance Control Variable . . . . . . . . . . . . . . . . . . . . . . . . . . . . 90
Cascade Control. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 90
Performance Set Point . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 91
Limiting Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 91
Limiting Control Threshold . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 92
Control Response . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 92
Chapter 6 Generator Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 93
Basic Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 93

March 2021 UM3307 (2.1.0)

8 Contents

Mode Selection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .93

Isochronous Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .94
Droop Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .95
Droop Dead Zone . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .96
Power Set Point . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .98
Load Limits. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .98
Megawatt Droop . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .99
Valve Droop . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .100
Breaker Fallback . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .101
Chapter 7 Output Variables . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .103
Intended Valve Position. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .103
Demand Clamps . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .104
Extraction Control Interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .104
Manual Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .105
Manual Override . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .105
Remote Manual . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .105
Actuator Control Signal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .106
Output Reverse . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .106
Valve Position Test . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .106
Chapter 8 States and Transitions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .107
Automatic Sequences . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .107
Start-Up Sequence . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .108
Permissive Conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .109
Failsafe Timer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .109
Stop Sequence . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .110
Critical Speed Avoidance. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .111
Critical Speed Stalling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .112
Coordinated Sequencing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .112
Overspeed Protection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .113
Electronic Overspeed Trip . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .113
Overspeed Trip Test . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .114
Load Loss Response . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .115
Overspeed Prevention . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .115
Appendix A Configuration Parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .117
Appendix B Controller Test Sequences . . . . . . . . . . . . . . . . . . . . . . . . . . . . .149
Index . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .163

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 Series 3++ Speed Controller 9

List of Figures
Figure 1-1 Cascade Control of a Turbine-Driven Process. . . . . . . . . . . . . . . . . . 15
Figure 1-2 Controlling Turbine-Driven Turbocompressors . . . . . . . . . . . . . . . . . 15
Figure 1-3 Controlling a Turbine-Driven Synchronous Generator . . . . . . . . . . . . 16
Figure 1-4 Series 3++ Extraction Control System . . . . . . . . . . . . . . . . . . . . . . . . 16
Figure 1-5 Speed Controller Functional Diagram . . . . . . . . . . . . . . . . . . . . . . . . 17
Figure 3-1 Field Termination Assemblies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53
Figure 3-2 Analog Input Signal Processing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55
Figure 3-3 Operation of Bipolar Output . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60
Figure 3-4 Operation of Hydraulic Actuator Requiring External Positioner . . . . . 62
Figure 3-5 Connecting a DPM to a Simplex Speed Controller . . . . . . . . . . . . . . 63
Figure 3-6 Communication With Other Controllers . . . . . . . . . . . . . . . . . . . . . . . 74
Figure 4-1 Typical Turbine Speed Profile . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 77
Figure 4-2 Speed Input Signal Processing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 81
Figure 4-3 MPU Signal Varies With Speed, Shaft Ratio, and Tooth Count. . . . . 82
Figure 5-1 Dead-Zone Error (E') as a Function of Actual Deviation . . . . . . . . . . 86
Figure 5-2 Functional Diagram of Cascade Loop . . . . . . . . . . . . . . . . . . . . . . . . 89
Figure 6-1 Proportional-Plus-PID Control Response. . . . . . . . . . . . . . . . . . . . . . 95
Figure 6-2 Megawatt and Valve Droop Control . . . . . . . . . . . . . . . . . . . . . . . . . . 99
Figure 6-3 Defining Power as a Function of Valve Position . . . . . . . . . . . . . . . 100
Figure 7-1 Output Variables and Transformations . . . . . . . . . . . . . . . . . . . . . . 103
Figure 8-1 Start-Up, Load, and Rated Sequences . . . . . . . . . . . . . . . . . . . . . . 108
Figure 8-2 Stop and Unload Sequences . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 110
Figure 8-3 Ramping Through a Critical Speed Range . . . . . . . . . . . . . . . . . . . 111
Figure 8-4 Typical Sequence of Overspeed Trip Test Events. . . . . . . . . . . . . . 114
Figure A-1 Series 3++ Engineering Panel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 118

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List of Tables
Table 3-1 Potential Analog Input Signals. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .56
Table 3-2 Available Symbols For Measured Variable Names and Units . . . . . . .58
Table 3-3 Available Analog Output Assigned Variables . . . . . . . . . . . . . . . . . . .59
Table 3-4 Discrete Input Functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .65
Table 3-5 Control Relay Functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .71
Table 3-6 Control Relay Functions (continued) . . . . . . . . . . . . . . . . . . . . . . . . . .72

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 Series 3++ Speed Controller 11

Symbols and Acronyms

Act Actuator variable
AD Analog-to-Digital variable
CCC Compressor Controls Corporation
CH analog input CHannel
CPU Central Processing Unit
CPU/IO PCB providing the main CPU and Input/Output Circuitry
CR Control Response or Control Relay
CRC Cyclic Redundancy Checksum
CS Control Signal
CV Control Variable or Control Valve
D Derivative response
DCS Distributed Control System
DI Discrete Input
e error
EEPROM Electrically-Erasable Programmable Read-Only Memory.
EOST Electronic Overspeed Trip Speed.
ESD Emergency ShutDown
FD Field Device.
FIM Field Input Module
FOM Field Output Module
FTA Field Termination Assembly
FT Flow Transmitter
FY Flow Transducer
HDIC High-Density Interconnect Cable
HMI Human Machine Interface
I Accumulated Integral Response
I Integral response change
I/H Current-to-Hydraulic signal converter
I/O Input and/or Output (circuits or signals)
I/P Current-to-Pneumatic signal converter
IVP Intended Valve Position

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12 Contents

J Power
JD Power Demand
JT Total power output
J1 Power developed by high-pressure section
J2 Power developed by low-pressure section
LCD Liquid Crystal Display
LED Light Emitting Diode
LSP Local Set Point
LVDT Linear Variable Differential Transformer (position input)
M extraction decoupling coefficient
MOR Manual Override
MOST Mechanical Overspeed Trip Speed
MPU Magnetic PickUp
NO/NC Normally-Open or Normally-Closed
NOR Normal Operating Range
MW Mega-Watt, also used as a generic electrical power measurement
N rotational speed (generally, the Number of revolutions per unit time)
N0 Rated Speed
OUT analog OUTput
P Pressure
PL Pressure in low-pressure extraction line
PC (IBM-PC compatible) Personal Computer
PCB Printed Circuit Board.
PCV Performance Control Variable
PIC Pressure Indicating Controller
PI Proportional-Integral control.
PID Proportional-Integral-Derivative control.
PSF Power Supply Failure
PSP Performance Set Point
PT Pressure Transmitter
Rs Ratio, shaft speed
RCS Redundant Control Selector
RFR Required Flow Rate

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 Series 3++ Speed Controller 13

RSP or RmSP Remote Set Point

rpm revolutions per minute
RVDT Rotary Variable Differential Transformer (position input)
S Solenoid
SCADA Supervisory Control and Data Acquisition
SE Speed measuring Element
SIC Speed Indicating Controller
SP Set Point
SPJ Power Set Point
SPS Speed Set Point
Spd selected rotational Speed
SV Signal Variable
T Temperature, also speed gear Tooth count
Tol Tolerance
TT Temperature Transmitter
TTC Total Train Control®
UIC User-defined multi-variable Indicating Controller, used to represent
an Antisurge Controller
Vac alternating-current Voltage
Vdc direct-current Voltage
V1 Valve 1 (high-pressure control valve)
V1 Valve 1 position
V2 Valve 2 (low-pressure control valve)
V2 Valve 2 position
Vac alternating-current Voltage
Vdc direct-current Voltage
W Mass flow rate, also Watt
W1 High-pressure section mass flow rate
W2 Low-pressure section mass flow rate
WD extraction Flow demand
WL Low-pressure extraction flow rate

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 Series 3++ Speed Controller 15

UM3307 Series 3++ Speed Controller

Chapter 1 Overview
This chapter summarizes this controller’s applications and features.

FY PT

SIC PIC

Figure 1-1 Cascade Control of a Turbine-Driven Process

Applications In simple cascade-control applications (see Figure 1-1), the Speed

Controller can not only vary the steam flow as needed to precisely
control any single-input process variable, but also provides a variety
of sequencing and protective features.

FY FT PT PT FT PT PT PT
TT TT TT TT

SIC UIC FY UIC FY PIC

Port 1 Serial Communication

Figure 1-2 Controlling Turbine-Driven Turbocompressors

In axial or centrifugal compressor applications (see Figure 1-2), the

Speed Controller can be combined with Series 3++ Antisurge and
Performance (or Dual-Loop A/P) Controllers to provide integrated
control, protection, and sequencing of the entire train.

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16 Chapter 1: Overview

Generator Breaker

Electrical Bus
MW
FY JT
CH7
Gen Input
SIC
Util Input
Isoch Input

Utility Grid Utility Breaker

Figure 1-3 Controlling a Turbine-Driven Synchronous Generator

In synchronous generator applications (see Figure 1-3), the Speed

Controller can not only switch between isochronous (frequency/
speed) and droop (power) control as circumstances dictate, but can
also provide a variety of sequencing and protective features (not
including autosynchronization). The power set point can be manipu-
lated by the built-in performance/cascade control loop.

High-Pressure Low-Pressure
Section Section
High-Pressure Header

V2
TT V1
Low-Pressure

FY
CV
Header

FY FT
PT

SIC PIC

Figure 1-4 Series 3++ Extraction Control System

In any of those applications employing single automatic extraction

or induction turbines (see Figure 1-4), the Speed Controller can be
combined with a companion Series 3++ Extraction Controller to pro-
vide closely-coordinated control of both the speed or load and the
extraction pressure or flow.

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 Series 3++ Speed Controller 17

PSP SV1 RSP LSP N1 N 2 N3 SV3

or or
PCV
SPS N

Loop Reverse fA Mode

Dead Zone Loop Reverse

SPS N J

JD
PCV PID Dead Zone or

off
MVAR Speed PID Droop PID
hi/lo
or

Auto/Manual
or
Speed Response

Demand Clamps

Power Demand (JD )

Flow Demand from
Loop Decoupling (Extraction Interface)
Extraction Controller
Required Flow Rate SV2

Physical Clamps Manual

Auto/Manual
or

Intended Valve Position

OUT Readout Output Reverse

Actuator Control Signal

Figure 1-5 Speed Controller Functional Diagram

Major Features This software revision (10611063-005) offers the following features:
• Speed Measurement using triple redundant, active or passive
magnetic pick-ups
• a Speed Control Loop that can smoothly switch between local,
remote, and cascade set points

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18 Chapter 1: Overview

• a Cascade/Limiting Control Loop that can be used to regulate

the driven equipment’s load or to limit any single-input variable
(such as the minimum inlet steam pressure)
• Single Extraction Turbine Control through full integration with
the Series 3++ Extraction Controller
• Generator Control that features automatic switching between
isochronous/frequency and droop/power (valve or megawatt)
control modes; local, remote, or cascade droop set points; and
additional overspeed prevention features
• Overspeed Protection and testing features
• Start-Up and Stop Sequences that minimize the risk of improper
warm-up, cool-down, or critical speed operation
• Automatic or Manual Operation from the Front Panel, a remote
operator panel, or a host computer or control system
• Redundant Controller Tracking that allows one Speed Controller
to serve as an on-line backup to another
• standard and extended I/O Hardware Configurations
• Analog and Discrete I/O ports that can be assigned functions
appropriate to each application, including a High-Current Output
that adapts to virtually any control valve
• Serial Communication with companion Series 3++ Controllers,
operator workstations, and Modbus host systems
• Configuration and Tuning from either the Engineering Panel
(from which three alternate parameter sets can be stored and
recalled) or from a computer workstation
Please refer to the Series 3++ Speed Controller [DS3307/V] for
information about previous revisions.

Speed Up to three magnetic pickups can be used to measure the turbine’s

Measurement speed (see Speed Inputs on page 81). These circuits accept the
frequency signals generated by active or passive magnetic speed
pickups. The controller is easily set up to calculate the actual speed
from these signals, the number of teeth on the measuring gear, and
the ratio of the measuring gear and shaft speeds.
If three MPUs are provided, two-of-three voting is used to select one
of their signals for control purposes. If two are connected, the higher
signal is selected. The operator is alerted if any enabled speed input
fails and the turbine is immediately shut down if all of them fall below
a user-specified control threshold.

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 Series 3++ Speed Controller 19

Speed Control The Speed Controller uses a PID control algorithm (see Control
Loop Response on page 92) to position the steam control valve as
needed to maintain the desired Speed Set Point (see page 87):
• The local set point can be varied from the Front Panel or by a
Modbus host.
• The remote set point can be varied by an analog input, compan-
ion Performance Controller, or Modbus host.
• The Cascade Set Point (see page 88) is calculated by the cas-
cade option of the Cascade/Limiting Control Loop.
When the desired speed rarely changes, the set point is usually con-
trolled by the operator, either from the Front Panel, via an analog
signal from a remote operator panel, or via an analog or serial signal
from a host workstation.
When the turbine speed must be varied to meet a related control
objective (for example, to regulate a pump’s discharge pressure),
either the cascade or remote set point might be used:
• For simple cascade-control applications, the internally calcu-
lated cascade set point might be used.
• For dynamic-compressor applications, selecting a remote set
point from a Performance Controller enables fully integrated
control and protection of both the compressor and turbine.
• If the driven machine is being regulated by a non-CCC device, it
can use an analog signal or Modbus communications to vary
the remote speed set point and the Speed Controller can indi-
cate via a control relay or Modbus discrete bit whether or not it is
using that set point.

Cascade/Limiting In addition to the speed control loop, the Speed Controller offers a
Control Loop second Cascade / Limiting Loop (see page 89) that can serve either
of two functions:
• In Cascade Control (see page 90) applications, it can vary the
speed or generator power set point as needed to keep the per-
formance control variable (PCV) at its desired value.
• In Limiting Control (see page 91) applications, it can directly
vary the control response as needed to keep the PCV above a
minimum or below a maximum value.

Single Extraction Series 3++ Speed and Extraction Controllers can be combined to
Turbine Control provide the closely-coordinated control needed to regulate a single
extraction or extraction-induction turbine’s rotational speed and
extraction pressure or flow, as described in the Series 3++ Extraction
Controller [UM3308].

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20 Chapter 1: Overview

Generator Control When configured for synchronous generator control, the Speed
Controller automatically selects isochronous or droop control based
on the states of its Gen, Util, and Isoch discrete inputs (see Mode
Selection on page 93). The Gen input usually indicates whether the
generator is on-line and the Util input indicates whether it is tied to
the public utility grid.
The Isochronous Control (see page 94) mode uses the previously-
described Speed Control Loop features to start the turbine and con-
trol its speed when the generator is off-line. It can also be selected
when the unit is on-line but disconnected from the utility grid.
The Droop Control (see page 95) mode uses proportional-integral-
derivative control to keep the generated power proportional to the
deviation of the turbine’s speed from its local, remote, or cascade
set point. The power output can be measured (see Megawatt Droop
on page 99) or inferred from the control valve position (see Valve
Droop on page 100).
In addition to the below-described Overspeed Protection features,
the Breaker Fallback (see page 101) will anticipate and attempt to
prevent excessive speeds if the generator breaker opens while the
generator is on-line, even if that breaker opens while the controller is
being manually operated.

This controller cannot automatically synchronize a generator to the

Caution: utility grid. It is the customer’s responsibility to see that the genera-
tor breaker is not closed until this synchronization is achieved.

Overspeed All steam turbines are equipped with overspeed trips that will shut
Protection them down if they exceed their maximum safe rotational speeds.
The Speed Controller offers several features that can test and aug-
ment this protection:
• The Overspeed Trip Test (see page 114) can be used to deter-
mine the Mechanical Overspeed Trip (MOST) speed at which
the turbine will shut itself down.
• The Electronic Overspeed Trip (see page 113) test supplements
(but can not replace) the mechanical trip by stopping the turbine
if an Electronic Overspeed Trip (EOST) speed is reached.
• The Load Loss Response (see page 115) feature can be used
to rapidly reduce the turbine’s power output in response to sud-
den load changes, possibly avoiding an emergency shutdown.

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 Series 3++ Speed Controller 21

• An Overspeed Prevention (see page 115) attempts to maintain

the steam turbine at an acceptable operating speed using and
open-loop step reduction in the steam flow demand.

A Series 3++ Speed Controller should not be used as a steam

Warning! turbine’s only or primary overspeed protection device.

Start-Up and Stop All of the Speed Controller’s Automatic Sequences (see page 107)
Sequences are based on one of the following sequences:
• The full Start-Up Sequence (see page 108) ramps the control
valve open until the turbine reaches a minimum closed-loop
control speed, then ramps the speed set point to the rated or
one of three idle speeds. If the turbine is running, portions of this
sequence can be used to accelerate it to any of those speeds.
• The ramped Stop Sequence (see page 110) can pause at an
idle speed while slowing the turbine to the speed at which an
emergency shutdown is triggered. Portions of this sequence can
also be invoked to slow the turbine to any of the idle speeds.
Critical Speed Avoidance (see page 111) minimizes the time spent
within either of two critical speed ranges. You can assign discrete
inputs for any Permissive Conditions (see page 109) that must be
met before a startup can be initiated, any of which can also be con-
figured to trigger an emergency shutdown.

Automatic or Because the Speed Controller is an automatic protective device, its

Manual Operation operation requires little (if any) operator intervention. Various front
panel, input/output, and computer communication features can be
used to monitored both the controller and your process and select
any enabled speed set point (see Continuous Operation on page
26), initiate or abort start-up and stop sequences and load or idle the
turbine (see Sequencing Operation on page 35), and directly posi-
tion the control valve (see Manual Operation on page 44).

Redundant Dual redundancy (that is, one-to-one fault tolerance) is a standard

Controller feature of most Series 3++ Controllers. This means you can install
Tracking one Speed Controller as an on-line “hot” backup to another, ready to
take over instantly if the first should fail.
In a typical application (see Tracking State on page 34), the two
controllers are interconnected via a Redundant Control Selector
(RCS) that connects the control element to the primary controller.
The backup controller then tracks (that is, monitors and duplicates)
the operating state, capacity set points, and control responses of the
active controller via the Port 1 serial communications link. If the pri-
mary controller’s fault relay de-activates, the system bumplessly
transfers control of your process to the back-up unit.

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22 Chapter 1: Overview

Hardware The Speed Controller can use either of two Hardware Options (see
Configurations page 53). The basic configuration provides back-panel terminals for
most of its I/O circuits, while the extended I/O option uses external
wiring modules to provide terminals for all of those circuits.

Analog and Each of the Analog Inputs (see page 55) is tested by comparing it to
Discrete I/O user-defined alarm limits. Some features are assigned specific
inputs, others can be configured to use any otherwise unused input.
The governor valve is generally manipulated by the High-Current
Output (see below), while the Standard Analog Outputs (see page
61) are used to drive external indicators for user-selected variables.
Each output circuit is internally monitored, but deviation alarms can
be enabled only for the high-current output and the actuator’s actual
position or intermediate control pressure (see Output Loopback Test
and Valve Position Test on page 106).
The controller’s Discrete Inputs (see page 64), and Control Relays
(see page 69) can be assigned a variety of functions, any of which
can be assigned to multiple inputs or outputs. The designated Fault
Relays (see page 69) de-activate if the controller stops running but
can also indicate various self-test failures.

High-Current Output A wide variety of valves can be used to control the flow of steam
to a turbine. These range from pneumatically actuated valves that
require “standard” 4 to 20 mA control signals to hydraulic valves that
may require external positioners. To this end, the High-Current Out-
put (see page 60) can be configured to provide virtually any uni- or
bipolar current-loop signal up to 200 mA.

Serial All Series 3++ Controllers have four Serial Ports (see page 74):
Communication • Ports 1 and 2 are used to coordinate their actions with other
CCC controllers (see Speed Control Loop, Single Extraction
Turbine Control, and Redundant Controller Tracking).
• Ports 3 and 4 are used for computer communications (see
Chapter 2), either via direct Modbus RTU communication or our
Series 3 OPC server program. This allows a Modbus host or an
OPC/DA client (such as our TrainView operator interface) to
monitor, configure and tune, or even control the operation of the
controller and turbine.

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 Series 3++ Speed Controller 23

Configuration and Each Speed Controller is adapted to its specific application by

Tuning assigning values to its configuration and tuning parameters (see
Appendix A). This can be done from the Engineering Panel or a
computer running our Series 3 Plus Configurator program.
Although the Speed Controller supports the definition of three alter-
nate sets of parameter values, it does not support discrete-input
selection among the first two sets (as compressor controllers do).

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 Series 3++ Speed Controller 25

UM3307 Series 3++ Speed Controller

Chapter 2 Operation
This chapter describes the operation and human-machine interface
features of the Speed Controller. To determine the meaning of
specific HMI elements, refer to the data sheets referenced below.

Operator This section summarizes the features that can be operated via the
controller’s front-panel, input and output circuits, and computer com-
Interfaces munication interfaces.
The front-panel keys, buttons, LEDs, readouts, and status screen
can be used to start or stop the turbine, select automatic or manual
operation, select the set point source, vary the PCV and local speed
set points, ramp the speed to specified levels, display and acknowl-
edge alarm messages, and display various internal and process
variables, as described in the Series 3++ Speed Controller
[DS3307/O].
Discrete input and output signals (see Chapter 3) can be used to
start or stop the turbine, select automatic or manual operation,
select the set point source, vary the local speed set point, ramp the
speed to user-defined levels, select a generator control mode, and
operate the front-panel status screen. An analog input can be used
to vary the remote set point. Process variable analog inputs can be
monitored directly, while some internal variables can be monitored
via analog outputs.
The computer communication interface allows Modbus hosts and
OPC/DA clients to start or stop the turbine, select automatic or man-
ual operation, select the set point source, vary the PCV and local or
remote set point, ramp the speed set point to user-defined levels,
and monitor various internal and process variables. The available
human-machine interface (HMI) variables are listed on the Series
3++ Speed Controller [DS3307/D] and the Series 3++ Speed Con-
troller [DS3307/M]. In addition, the TrainView program [UM5522]
describes the standard elements of its operator interface for these
controllers.

Because all three interfaces are always active, the turbine can be
monitored and controlled using any combination of their features.
Note: In this chapter, it is assumed that all discrete inputs and outputs
have positive functions, so that relays activate when their assigned
conditions exist and inputs initiate actions when asserted (set).

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26 Chapter 2: Operation

Continuous The operation of a Speed Controller regulating a single-valve steam

turbine depends on whether it is driving a Variable-Speed Load (see
Operation page 31) or a Synchronous Generator (see page 32):
• In a variable-speed application, the control element is varied to
maintain the desired speed.
• In a generator application, it is manipulated to maintain a certain
frequency or generate a specified amount of electrical power.
In either application, continuous control is applied when the turbine
is running at or above its minimum governor speed (see Sequencing
Operation on page 35). The Run LED is then lit, any Run relays are
activated, and the Modbus Run discrete and OPC Run variable
are set. Manual Operation can be selected and Limiting Control is
initiated if enabled and necessary.
The operation of an automatic induction or extraction turbine is
described in Chapter 2 of UM3308.

Control Element The intended position of the steam control valve (in percent open)
Position can be monitored via the OUT readout, any analog output assigned
an Act function, or the Modbus OUT Display register and OPC Out-
_Display variable. If a valve position or actuator pressure analog
input signal is provided, it can be monitored via its Analog In Menu
screen, Modbus Channel 4 register, or OPC CH4_scaled variable.
A “HiActuator” alarm is triggered and the High Clamp discrete and
High_Clamp variable are set whenever the intended valve position
equals or exceeds its configured maximum value. A further increase
in the load on the turbine would then prevent the controller from
maintaining the desired speed.
Conversely, a “LoActuator” alarm is indicated and the Low Clamp
discrete and Low_Clamp variable are set if a further load reduction
would cause the speed to exceed its set point because the valve is
at or below its configured minimum position.
In an extraction control application, a clamp condition is indicated
when the governor valve (V1) is at or beyond one of its physical
clamp limits. If the speed control response is at or beyond one of its
demand clamp limits, the Limit LED is lit, any Limt relays are acti-
vated, and the Limit discrete and Limit variable are set.

Speed and Set Unless the CASC, LIMIT, or POWER button is pressed, the front-
Point panel RPM and SP readouts display the turbine’s rotational speed
and the speed or droop set point (in rpm). Those variables can also
be monitored via any analog outputs assigned the Spd and SP func-
tions, the Modbus RPM Display and SP Display registers, or the
OPC RPM_Display and SP_Display variables.
The RPM will display when the MPU is disabled.

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 Series 3++ Speed Controller 27

In a Variable-Speed Load application, any enabled (local, remote, or

cascade) speed set point can be selected. In a Synchronous Gener-
ator application, any enabled power set point can be selected but
isochronous (speed) control can only employ a local set point. In
either case, the selected set point source can be identified by:
• viewing the front panel Remote, Local and Cascade LEDs (one
of which is always lit), or
• monitoring any Remote or Cascade control relays, the Modbus
Remote and Cascade discrete inputs, or the OPC Remote and
Cascade variables (none of which are set when the local set
point is selected).
The set point source can be changed by selecting a different Set
Point Mode (see DS3307/O), asserting a discrete input, forcing
Modbus coils, or setting OPC variables (as discussed below)

Local Set Point The local set point has both a target and an effective value. When it
is selected:
• The target value can be changed by 1 rpm by pressing the
Raise or Lower key, or ramped up or down at a configured rate
by holding one of those keys down. It can alternately be ramped
by asserting a Speed Up or Speed Down discrete input while
monitoring any analog output assigned the SP function. If the
Computer RSP discrete and Computer_RSP variable are off,
the target value can also be directly set by writing to the Speed
SP holding register or Speed_SPW variable.
• The effective value is constant when it equals the target value,
otherwise it is ramped toward that target at a configured rate.
This set point can be activated by selecting the corresponding Set
Point Mode, asserting a Local discrete input, or clearing the Modbus
Remote and Cascade coils or the OPC RemoteW and CascadeW
variables. That would light the Local LED, de-activate any Remote
and Cascade control relays, and clear the Modbus Remote and
Cascade discretes and OPC Remote and Cascade variables. To
prevent a sudden control response change, both the target and the
effective value would be initialized to the current speed or power.

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28 Chapter 2: Operation

Remote Set Point The remote set point is varied by any one of three possible sources:
• If the Computer RSP discrete and Computer_RSP variable are
On, it can be changed only by writing to the Modbus Speed SP
register or the OPC Speed_SPW variable. Its value will remain
constant if communication is disrupted.
• Otherwise, it is controlled via serial communication from a
Series 3++ Performance or Dual-Loop Controller or an analog
signal from a third-party device or an external operator panel.
If both of those sources are enabled, the analog signal is used
only when an Analog Remote discrete input is set. If communi-
cation with that controller is lost or that input fails, the local set
point is selected and set to the current speed. Correcting the
problem would not automatically reselect the remote set point.
The remote set point can be activated by selecting the correspond-
ing Set Point Mode, asserting the Remote discrete input, or setting
the Modbus Remote coil or OPC RemoteW variable. That would
light the Remote LED, activate any Remote control relays, and clear
the Modbus Remote discrete and OPC Remote variable. To prevent
a sudden control response change, the remote set point would ramp
from the value of the previously selected set point (local or cascade)
to the current value from the remote source.
The Speed Track discrete and Speed_Track variable are set when-
ever the remote set point is not selected or the controller cannot
satisfy it due to some limiting condition or manual operation.
Any Set Point Track (SPtk) relays are set whenever the analog
remote set point is not selected or the controller cannot satisfy it due
to some limiting condition or manual operation. The source of that
set point should then track the Speed Controller’s speed or
speed/droop set point.

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 Series 3++ Speed Controller 29

Cascade Set Point The cascade set point is calculated from the deviation of the perfor-
mance control variable (PCV) from its own set point:
• When generator control is not enabled, the PCV control loop
can be used to control the throughput of the driven device by
dynamically calculating and maintaining the appropriate speed
(see Variable-Speed Load on page 31).
• When generator control is enabled, that loop can be used to
vary the generated power as needed to maintain the desired
PCV value (see Synchronous Generator on page 32).
PCV and its set point can be displayed by pressing the CASC button
or via the Control Menu (see DS3307/O). When displayed by the
status screen, that set point can be increased or decreased by 0.1
percent by pressing the Raise or Lower key, or ramped up or down
at a steadily increasing rate by holding one of them down. It cannot
be changed via discrete or analog inputs.
The Cascade Enabled discrete and Cascade_Enabled variable indi-
cate whether this loop is enabled. If they are set, the PCV and its set
point can be monitored via the Modbus PCV and PCV SP registers
and the OPC PCV/PCV% and PCV_SP/PCV_SP% variables. That
set point can be changed via the PCV SP holding register or the
PCV_SPW/PCV_SPW% variable.
Cascade control can be activated by selecting the corresponding
Set Point Mode, asserting the Cascade discrete input, or setting the
Modbus Cascade coil or OPC CascadeW variable. That would light
the Cascade LED, activate any Cascade control relays, and clear
the Modbus Cascade discrete and OPC Cascade variable.
To prevent a sudden control response change, the cascade set
point would ramp from the value of the previously selected set point
(local or cascade) to the current value from the remote source. If the
PCV set point was set up to track that variable when the remote or
local set point is selected, it would remain constant unless displayed
and changed. Otherwise, it would ramp from the value of PCV to the
value it had when cascade control was previously active.
If all enabled inputs for the PCV fail, the local set point is selected
and set to the current speed. Correcting the problem would not auto-
matically reselect the cascade set point.

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30 Chapter 2: Operation

Speed Alarms If the speed deviation exceeds a configured amount for more than a
configured number of seconds, a “Speed Dev” alarm is triggered,
any Speed Deviation (NDev) relays activate, and the Speed Dev
discrete and Speed_Dev variable are set.
Either of two possible speed switch conditions will be indicated by
triggering the corresponding “SpdSwitch#” alarm, energizing any
relays assigned the corresponding Swi# function, and setting the
Modbus Speed Switch # discrete and OPC SpeedSwitch# variable.
Depending on how they are configured, these indicators are trig-
gered when the turbine speed rises above or falls below a threshold
speed, and clear either when that condition is rectified or the result-
ing alarm is acknowledged.

Limiting Control If the limiting control loop is enabled and the performance control
variable (PCV) reaches its limiting threshold, the control response
(intended valve position) will be adjusted to restore an acceptable
PCV value. This limiting response is subject to these limitations:
• It cannot vary the steam demand beyond the minimum or maxi-
mum demand clamp.
• It cannot raise the turbine speed beyond maximum governor,
nor lower it below minimum governor.
Whenever the limiting condition exists, the Limit LED is lit, any Limt
relays are activated, and the Modbus Limit discrete and OPC Limit
variable are set:
• The PCV and its set point can be displayed by pressing the
LIMIT button, or by selecting it from the Control Menu. When
displayed by the status screen, the limiting threshold can be
changed by 0.1 percent by pressing the Raise or Lower key, or
ramped up or down at a steadily increasing rate by holding one
of them down. It cannot be changed by field inputs.
• They can also be monitored via the Modbus PCV and PCV SP
input registers and OPC PCV/PCV% and PCV_SP/PCV_SP%
variables, and that threshold can be changed via the PCV SP
holding register or PCV_SPW/PCV_SPW% variable. The Mod-
bus Limit Enabled discrete and OPC Limit_Enabled variable
indicate whether or not this loop is enabled.
This loop would be suspended if all PCV analog inputs failed.

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Variable-Speed When a turbine is used to drive a variable-speed device, the speed

Load of the entire unit will decrease or increase as the load on the driven
device rises above or falls below the power output of the turbine:
• If the goal is to maintain a constant speed (that is, if the speed
can but should not vary), a PID control loop varies the steam
flow (and thus the power output) to counter any speed changes.
Such applications use either a local or remote set point.
• If the goal is to control the throughput of the driven machine,
cascaded PID control loops maintain a process flow or pressure
by calculating and maintaining the appropriate speed. For
example, the flow through and suction and discharge pressures
of a compressor can be stabilized by adjusting the speed as the
resistance to that flow varies.
For simple driven devices, such as a pump, the Speed Control-
ler’s internal cascade loop can be used to calculate the speed
set point (see Cascade Set Point on page 29). For more com-
plex control applications, a remote set point can be calculated
by an external controller and transmitted to the Speed Controller
via an analog signal or serial communications.
If the driven device is an axial or centrifugal compressor, Series
3++ Speed, Performance, and Antisurge Controllers can be
combined to provide fully -integrated control and protection of
both machines (the Performance Controller would use Port 1
serial communication to vary the remote speed set point).
When the controller is operating in its Run state and generator con-
trol is disabled, any enabled speed set point can be selected and
the active one can be identified as discussed under Speed and Set
Point on page 26. In addition, the local set point can be selected and
ramped to an idle or rated speed (see Sequencing Operation on
page 35).

The remote or cascade set point is used only when the controller is
in its Run operating state and the turbine speed exceeds minimum
Note: governor. Under any other conditions, selecting one of those set
points causes the corresponding LED to flash, thus indicating the
controller is actually using its local set point.

Only the local set point can have a value outside the normal oper-
ating range. It can be raised above maximum governor during an
overspeed trip test, and can be left below minimum governor at the
conclusion of an automatic sequence. However, it can never be
directly lowered below the next lowest of the Idle1, Idle2, or Mini-
mum Governor speeds.

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32 Chapter 2: Operation

Synchronous When several generators are tied to a common bus, electromag-

Generator netic forces hold them all at the same frequency, thus forcing them
to operate at their synchronous speeds. The frequency and speeds
will rise if the total power generated exceeds the total electrical load,
or will fall if too little power is generated.
In such cases, the desired frequency is usually maintained by using
standard PID techniques to control one generator’s speed, thus
varying its output as needed to match the total power generated to
the total load. This is referred to as Isochronous Operation. Another
technique known as Droop Operation is used to keep the power out-
puts of the other generators proportional to the droop (difference)
between their actual speeds and speed set points.
The generated power is usually fed to a local electrical bus via
a generator breaker. The unit is said to be on-line if that switch is
closed, or off-line if it is open. In turn, that bus is usually connected
to the public utility grid via a utility breaker. The electrical frequency
and turbine speeds must be regulated only if that switch is open, by
controlling one of the local generators isochronously.
A Speed Controller will apply either droop or isochronous control,
depending on the states of its Gen (generator breaker), Isoch (iso-
chronous), and Util (utility breaker) discrete inputs:
• The Gen and Util inputs are usually controlled by the corre-
sponding breakers, so the appropriate method is selected
automatically as they open or close.
• The Isoch input determines which method will be used when
the generator is on-line but not connected to the grid (droop is
always used when connected). Your controller can be set up
to always choose one method or the other, or a Droop/Isoch
switch can be installed to allow your operator to choose.
The Gen Enabled discrete and Gen_Enabled variable indicate
whether or not generator control is enabled. If so, the Gen Breaker
discrete and Gen_Breaker variable are set and the GenPwr LED
lights when the Gen input is asserted, thus indicating power is being
generated. The operating state displayed by the status screen Con-
trol Menu will indicate the selected control mode:
• Isoch means the generator is under isochronous control.
• Droop means the generator is under droop control.
• Spd/Droop or Spd/Isoch indicates the generator is off-line and
the controller will switch to the indicated mode if the generator
breaker is closed.
The states of the utility and isoch inputs can be monitored via the
corresponding DI Condition discrete bits and OPC DI# variables.

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 Series 3++ Speed Controller 33

Isochronous Isochronous control is selected whenever the generator is on-line

Operation (Gen input set), all Util inputs are cleared, and the Isoch input is set.
The operating state then displays as “Isoch” to indicate the controller
is regulating the turbine speed and the resulting frequency
The remote and cascade set points cannot be selected. The local
set point, which should not be changed unless the frequency is per-
sistently too high or low, is initialized to the Rated Speed when this
mode is initiated. If the controller is unable to maintain the desired
speed and frequency (for example, if it reaches a steam demand
limit or the limiting variable reaches its control threshold), the power
outputs of any interconnected generators should be raised or low-
ered by adjusting their droop set points.

Droop Operation Droop control is selected if the Gen input is asserted and any Util
input is set or the Isoch input is cleared. The state then displays as
“Droop” and the Droop discrete and Droop variable are set.
The actuator control signal is then kept proportional to the difference
between the speed and the speed/droop set point. In turn, that set
point is a linear function of the desired power. For a 60 Hz, 3600 rpm
generator with a 5.0 percent droop gain, for example, the
speed/droop set point would rise from 3600 to 3780 rpm as the
desired power rose from 0 to 100 percent:
• The speed and speed/droop set point (in rpm) are displayed by
the RPM and SP readouts and can be monitored via the RPM
Display and SP Display registers and OPC RPM_Display and
SP_Display variables.
• The generated power and its set point can be displayed by
pressing the POWER button or selecting the Control Menu and
pressing SCROLL until the Power screen appears. They can
also be monitored via the Power CV and Power SP registers
and Power/Power% and Power_SP/Power_SP% variables.
Any enabled power set point can be selected, as discussed under
Speed and Set Point on page 27, and can have any value between
the minimum and maximum Load Limits (see page 98):
• If the Cascade discrete and Cascade variable are On, the set
points are controlled by the performance control loop (see Cas-
cade Set Point on page 29).
• If the Remote discrete and Remote variable are On, the remote
set points are selected. If the Computer RSP discrete and Com-
puter_RSP variable are also On, they can be changed only by
writing the desired power output to the Power SP holding regis-
ter or Power_SPW/Power_SPW% variable. Otherwise, they are
controlled by an analog input or companion controller.

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34 Chapter 2: Operation

• If the Cascade and Remote discretes and Cascade and Remote

variables are Off, the local set points are selected and can be
changed from the front panel. If the Computer RSP discrete and
Computer_RSP variable are also Off, they can also be changed
by writing the desired power output to the Power SP holding
register or Power_SPW/Power_SPW% variable.
A “Max Load” alarm is indicated if the power set point reaches its
high clamp, and the Power Limit discrete and Power_Limit variable
are set as long as it remains there.
In valve droop applications, the generated power is estimated from
the intended valve position. In megawatt droop applications, it is an
actual measurement. If the power input fails, the controller reverts to
valve droop, indicates a “MW Fallbck” alarm, and sets the Power
Fallback discrete and Power_Fallback variable.
If the generator breaker opens unexpectedly, the Breaker Fallback
(see page 101) will immediately act to prevent a turbine overspeed.
Unless they have been configured to shut down the turbine, the con-
troller will then switch to isochronous control with its local set point
equal to either the Minimum Governor or Rated Speed.
If Limiting Control is enabled and becomes necessary, droop control
is resumed as soon as PCV is restored to an acceptable value. The
local set point will retain its value while the controller is limiting PCV,
and the limiting loop can not drive the generated power below the
specified minimum load limit.

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 Series 3++ Speed Controller 35

Sequencing Turbine startups and shutdowns can be initiated from the front
panel, by asserting an associated, previously-cleared discrete input,
Operation or by setting an associated Modbus coil or boolean OPC variable:
• When a turbine is running at or above its minimum governor
speed, its Speed Controller will operate in its Run state (see
Continuous Operation on page 26).
• If the turbine is running at a speed below minimum governor, its
Speed Controller will operate in its Idle State.
• If the controller is operating in its Run or Idle state, initiating a
Ramp to Idle will bring the turbine to a specified idle speed.
• If the controller is operating in its Idle state, initiating a Ramp to
Rated will bring the turbine to the configured Rated Speed.
• If the governor valve is fully open (or under manual control) and
the speed remains within a configured critical range beyond a
specified maximum time, a Critical Speed Stall is triggered.
• Initiating an Emergency Shutdown immediately trips the turbine.
• Initiating a Ramped Stop gradually slows and cools down the
turbine before tripping it.
• Either shutdown will leave the controller operating in its Shut-
down State. It must then be reset to its Ready State before the
turbine can be restarted.
• If the controller is in its Ready state, initiating a Turbine Startup
will bring the turbine to a specified target speed.
Any Stop relays and the Stop discrete and Stop variable are set if
the speed set point is being ramped or is below minimum governor.
Initiating any sequence aborts any other already in progress, as
does switching to manual. Provided the set point is above the Idle1
Speed, you can also interrupt any ramping sequence by pressing
the Raise or Lower key, asserting a SpdUP or SpdDn input, or set-
ting the Modbus Halt Ramp coil or OPC Halt_RampW variable:
• If the set point is above Minimum Governor, the controller will
select its Run state (see Continuous Operation on page 26).
• If the set point is below Minimum Governor, the controller will
select its Idle State (see page 36).
In a generator application, the generator breaker should be open
(and all Gen inputs should be cleared) when the unit is shut down or
off-line. The Turbine Startup or Ramp to Rated sequence can then
bring it up to its synchronous speed, after which electrical synchroni-
zation must be achieved before closing the generator breaker.
Either the Ramped Stop or Emergency Shutdown can be used to
shutdown either a loaded or idled generator, but the operator must
take the generator off-line before the Ramp to Idle sequence can be
used to reduce its speed.

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36 Chapter 2: Operation

Idle State The Idle state is selected if the speed is below Minimum Governor at
the end of a ramped sequence or when manual operation is termi-
nated. The operating state displays as “Spd/Local”, the Idle LED is
lit, and the Modbus Stop discrete and OPC Stop variable are set.
Raising the speed to Minimum Governor would select the Run state:
• The local set point can be ramped by pressing the Raise or
Lower key or asserting a SpdUP or SpdDN input, or by initiating
a Ramp to Rated (see page 38). It cannot be changed via com-
puter communications, even if the Computer RSP discrete or
Computer_RSP variable is Off. If one of the idle speeds equals
Minimum Governor, initiating the corresponding Ramp to Idle
(see page 37) would also raise the speed to the Run threshold.
• If Manual Operation is initiated and the valve is opened far
enough to raise the speed above minimum governor, the Run
state will be selected when automatic operation is restored.
The set point that would be activated if the speed was raised above
Minimum Governor is indicated by:
• lighting the Local LED if the local set point is selected,
• flashing the Remote LED and setting the Remote coil if the
remote set point is selected, or
• flashing the Cascade LED and setting the Cascade coil if the
cascade set point is selected.
All other remote and cascade coils, registers, and variables are
cleared and any Rem or Casc relays are de-activated whenever the
speed is below Minimum Governor.

Idle Indicators In addition to any Stop relays and the Stop discrete and Stop OPC
variable (which are set when the speed set point is below minimum
governor and during any ramped sequence), separate relay assign-
ments and Modbus and OPC variables are provided for each of the
optional idle speeds:
• Idl3 relays and the Idle3 discrete and Idle3 variable are set if the
speed is between the Idle3 Speed and Minimum Governor.
• Idl2 relays and the the ESD coil (22) is. See: Idle State in Chap-
ter 2.Idle2 discrete and Idle2 variable are set if the speed is
between the Idle2 Speed and the Idle3 Speed (or Minimum
Governor, if the Idle3 Speed is zero).
• Idl12 relays and the Idle1 discrete and Idle1 variable are set if
the speed is between the Idle1 Speed and the Idle2 Speed (or
Minimum Governor, if the Idle2 Speed is zero).

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 Series 3++ Speed Controller 37

Ramp to Idle If the controller is operating in its Run or Idle state, selecting the
Idle1, 2 or 3 operating mode, asserting an Idle1, Idle2, or Idle3
discrete input, or setting the Modbus Idle1, the ESD coil (22) is. See:
Idle State in Chapter 2.Idle2, or Idle3 coil or OPC Idle1W, Idle2W, or
Idle3W variable initiates a Ramp to Idle that will bring the turbine to
the corresponding speed and hold it there. This allows a loaded tur-
bine to be taken off-line without shutting it down, or cooled down
prior to stopping it:
• Initiating an idle ramp while the speed is above the correspond-
ing target speed will initiate a partial Stop Sequence, which
selects the local set point, sets it to the current speed, and
ramps it down to the target speed at the Shutdown Ramp Rate.
If the speed is above Minimum Governor, the Run LED will
remain lit, an “IdleEnable” alarm is indicated, and the idle
sequence can be cancelled until the Shut-Down Delay elapses.
• Initiating an idle ramp while the turbine is operating below the
corresponding speed will ramp the local set point up to that
speed at the Initial Startup Ramp Rate.
The Idle LED flashes during the sequence and lights when its target
speed is reached. The Idle Indicators (see page 36) operate as pre-
viously described.

Idling a Generator In a generator control application, the turbine cannot be idled while
the generator breaker is closed (the set point must be lowered until
that breaker opens before any idle ramp can be initiated).

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38 Chapter 2: Operation

Ramp to Rated If the controller is operating in its Idle state, selecting the Rated
mode, asserting a Rated Mode input, or setting the Rated coil or
RatedW variable will initiate a partial start up ending at that speed.
The Run LED will then start to flash as the local set point is selected
and set to the current speed:
• If the initial speed exceeds the configured Idle2 Speed, that set
point is simply ramped to the Rated Speed at the Final Startup
Ramp Rate.
• Otherwise, the local set point is increased at the Initial Startup
Ramp Rate until it reaches the Idle2 Speed, and is then ramped
to the Rated Speed at the Final Startup Ramp Rate.
In any case, the Run LED is lit (stops flashing), the Rated coil and
RatedW variable are cleared, and the Run relay, Run discrete, and
Run variable are set when the local set point reaches the Rated
Speed or this sequence is interrupted above Minimum Governor. If
the remote or cascade set point is selected, the speed control loop
will then switch to that set point, its LED will light (stop flashing), its
Modbus discrete and OPC variable will be set, and the operating
state will display as “Spd/Casc” or “Spd/Remote”.
You can also bring an idling turbine on-line by raising the local set
point to Minimum Governor. It then switches to the Run state:
• If the remote set point is selected, the speed control loop then
ramps it from Minimum Governor to the remotely-set value.
• If the cascade set point is selected, it is ramped from Minimum
Governor to the control response of the cascade control loop.

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 Series 3++ Speed Controller 39

Critical Speed If the speed remains in a configured critical range for more than a
Stall user-specified number of seconds while the intended valve position
is at its high clamp, the controller will:
• indicate a “CRZ Stall” alarm,
• select its Idle State, and
• reduce the local set point to the lower limit of that critical range.
This response is also triggered if the speed remains in a critical
range for more than the configured number of seconds while it is
being manually manipulated, in which case the controller will also
revert to automatic operation.
The Modbus CRZ Stall discrete and OPC CRZ_Stall variable are set
whenever the associated timer is running (that is, when the speed is
within a configured critical range and the IVP is at its high clamp or
under manual control).
The “CRZ Stall” alarm cannot be cleared while the speed is within
the critical zone.

Emergency Selecting the Shutdown mode, asserting an ESD Mode input, or set-
Shutdown ting the ESD coil or ESDW variable simply and immediately stops
the flow of steam to the turbine. It is initiated by selecting the Shut-
down operating mode, by triggering an ESD discrete input, or by
setting the Modbus ESD coil or OPC ESDW variable.
Asserting the ESDae (always enabled) input initiates an emergency
shutdown in any operating state, including the Ready State. While
this input is active, the controller cannot be Reset or switched to
Manual Operation.
Unlike the Stop sequence, you are not given time to change your
mind when initiating an ESD. Instead, the controller immediately
drops its speed control response to zero, lights the ESD LED, and
sets the Modbus ESD coil and Shutdown discrete and the OPC
ESDW and Shutdown variables. Any SD or ESD relays are also
activated (SD relays remain set until the controller is reset, while
ESD relays remain set for only five seconds.
An emergency shutdown is also automatically initiated when the
controller detects any of the following trip conditions:
• exceeding the electronic overspeed trip (EOST) threshold,
• failure of all enabled speed input signals,
• failure to detect rotation during startup,
• opening of the generator breaker (load loss),
• watchdog fault of the CPU/IO board, or
• failure of the auxiliary/speed board.

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40 Chapter 2: Operation

Ramped Stop The ramped stop sequence gradually reduces the steam flow until
the speed falls below the Minimum Control Speed, and then triggers
an Emergency Shutdown. It can be initiated by selecting the Stop
mode, asserting a Stop Mode input, or setting the Modbus Stop coil
or the OPC StopW variable. Doing so will cause the Stop LED to
flash and set the Modbus Stop coil and OPC StopW variable.
If this is done while the speed is above Minimum Governor (Run
state), the Stop LED will immediately begin to flash but nothing else
will happen until the Shut-Down Delay has elapsed. In the mean-
time, you can cancel the shutdown by initiating Manual Operation
and then switching back to automatic, or selecting the Rated mode
or setting any of that mode’s other triggers. If the speed is below
Minimum Governor (Idle state), this delay is skipped.
Following that delay, the local set point is selected, set to the current
speed, and ramped down until the turbine trips. The Idle Indicators
(see page 36) operate as previously described.
You can abort this sequence by pressing the Raise or Lower key,
asserting a SpdUp or SpdDN input, or setting the Halt Ramp coil or
Halt_RampW variable. The controller would then select its Run state
or Idle state, depending on whether the speed was above or below
Minimum Governor.

Generator Shutdown If droop control is active when a Ramped Stop is initiated, the con-
troller will ramp its speed/droop set point down until the generator
breaker opens (this usually occurs automatically when the generator
ceases to provide power). Speed control is then initiated and the
turbine is shut down as previously described.
If the turbine is under isochronous control when such a ramped stop
is initiated, the local set point is simply selected and ramped down:
• If the unit is on-line and there are other generators supplying
power to the same bus or grid, the controller will be unable to
slow the turbine but its attempts to do so will unload the genera-
tor. This should eventually cause the generator breaker to open,
after which the speed will start to fall.
• If the generator is on-line and the only one supplying power to
its bus, the speed, frequency, and power output will immediately
decrease. Because this could damage any device on that bus, it
would be better to initiate an Emergency Shutdown.
If a stop is initiated while the generator is on-line, the speed will
always be above Minimum Governor and the Shut-Down Delay is
always applied. This means you can cancel the requested transition
by initiating Manual Operation or reselecting the Rated mode before
that delay elapses (that is, while the Run LED is flashing).

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 Series 3++ Speed Controller 41

Shutdown State In the Shutdown state, which is selected when the turbine is tripped
or at the conclusion of a ramped shutdown, the steam control valve
is held fully closed. The turbine cannot be restarted and the control-
ler cannot be operated manually.
When this state is selected, the ESD and Auto LEDs are lit, SD and
Stop relays are tripped (Rdy relays are not). The Modbus ESD coil
and Shutdown discrete are set, as are the OPC ESDW and Shut-
down variables. The cause of the most recent shutdown can be
displayed via the Control Menu or can be determined by reading the
Last ESD register. You can determine the reasons for the last eight
shut downs (and the times at which they occurred) by scrolling the
SD Log Menu, and the last three can be read via the corresponding
OPC Last_ESD1 OPC variables.
The controller can be reset to its Ready state (which activates any
Rst relays for one second and also clears all alarms) by pressing the
ESD RESET key, setting any previously-cleared Reset input, or
setting the Ready coil or ReadyW variable. (Note: the controller can-
not be Reset while the ESDae input is True). In extraction control
applications, this will also clear all Extraction Controller alarms.

Ready State In the Ready state, which is selected by resetting the controller from
its Shutdown State, the control valve is held fully closed unless the
controller is being manually operated. The local set point cannot be
changed, even if selected, but the performance/limiting set point can
be (see Cascade Set Point and Limiting Control). The Stop LED is
lit, Stop relays are activated (SD relays are not), the Ready coil and
ReadyW variable are set, and the SP readout displays the Minimum
Control Speed.
A startup can be initiated only if all Permissive Conditions (see page
109) are met, in which case all Rdy relays will be tripped, the Ready
discrete and Ready variable will be set, and the operating state will
display as “Ready to Run”. Otherwise, the Ready indicators will be
cleared and the operating state will display as “NotRdyPerm”
(cleared Permissive inputs) or “NotRdy ESD” (set ESD inputs). You
should have a list of these inputs, which can be monitored via the
In/Out Menu or the associated Modbus DI Condition discretes and
OPC DI# variables.
You can change the set point source, as discussed under Speed
and Set Point on page 26, but that source would not be used until
the speed was raised above Minimum Governor. The selected
source is indicated as in the Idle State.
If the ESDae input is asserted while the controller is in the Ready
state, an Emergency Shutdown will be triggered. The controller can-
not be Reset while the ESDae input is True.

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42 Chapter 2: Operation

Turbine Startup You can initiate the Start-Up Sequence in any of the following ways:
• by selecting the operating mode (Idle1, Idle2, Idle3, or Rated)
corresponding to the desired final speed from the front panel;
• by asserting an Idle1 Mode, Idle2 Mode, Idle3 Mode or Rated
Mode input and then asserting a Startup (Run) input;
• by setting the Modbus Idle1, the ESD coil (22) is. See: Idle State
in Chapter 2.Idle2, Idle3, or Rated coil and then setting the Run
coil; or
• by setting the OPC Idle1W, Idle2W, Idle3W, or RatedW variable
and then setting the RunW variable.
For a start up to the rated speed, you should first select the set point
that should be activated when that speed is reached. If a startup is
initiated without first selecting the target speed, it will terminate at
the Idle1 Speed.
The start-up sequence initially ramps the control valve open. Local
set point control is initiated (and any Strt relays are activated for one
second) when the minimum control speed is reached. That set point
is then ramped to the target speed:
• If an Idle mode was chosen, the Idle LED will light (stop flash-
ing) and the Idle1, the ESD coil (22) is. See: Idle State in
Chapter 2.Idle2, or Idle3 coil and Idle1W, Idle2W, and Idle3W
variables will clear when the target speed is reached. The oper-
ating state will display as “Spd/Local”.
If the remote or cascade set point is selected, that LED will flash
until the speed is increased to minimum governor by raising the
local set point. Remote or cascade set point speed control is
then initiated and the Remote or Cascade discrete is set.
• If the Rated mode was selected, the Run LED will light (stop
flashing) and the Rated coil and RatedW variable will clear
when that speed is reached. If the remote or cascade set point
is selected, that LED will also stop flashing and the correspond-
ing discrete bit will be set. The operating state will display as
“Spd/Casc” or “Spd/Remote”.
Any Idl1 relays, the Idle1 discrete, and the Idle1 variable are set
when the set point passes the idle1 speed. When it passes the idle2
speed, the Idle1 indicators are cleared and those for Idle2 are set.
When it passes the idle3 speed, the Idle2 indicators are cleared and
those for Idle3 are set. The Idle3 indicators are cleared at minimum
governor. If any of those thresholds are disabled, the corresponding
indicators never set and those for the previous speed clear at mini-
mum governor. The Run relay, Run discrete, and Run variable are
not set until the rated speed is reached or the startup is halted
above minimum governor.

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 Series 3++ Speed Controller 43

Manual Startup If you select Manual Operation while the controller is ready for a
startup, you can also start the turbine by manually raising the IVP
until the desired speed (which must be at least the Minimum Control
Speed) is reached. Selecting manual during an automatic startup
will terminate that sequence.

The controller cannot be switched to Manual control while an ESD

Note: discrete is active or the ESDae input is True.

Generator Startup Unless you are Black Starting the unit, a generator’s frequency and
phase angle must be matched to that of its electrical bus (either by
the operator or an external sequencer) before the generator breaker
is closed, and the controller should switch to droop control when the
generator is brought on line. With a Series 3++ Speed Controller, this
synchronization must be provided by having the operator or an
external device fine-tune the local set point after the turbine reaches
its synchronous speed. It is your responsibility to see that the gener-
ator breaker is not closed until this synchronization is achieved.

Severe equipment damage can occur if a generator is brought

on-line while it is “out-of-sync” with the utility grid. Thus, it is
Warning! vitally important to match its frequency and phase angle to the
grid before closing the generator breaker.

The operating state will usually display as “Spd/Droop” to indicate

droop control will be selected when the Gen input is asserted. Once
the Rated Speed has been reached and synchronization has been
achieved, the generator breaker can be closed. Assuming that this
asserts a Gen input, the controller will then initiate droop control with
its set point initialized to its minimum load value, and the displayed
operating state will change to “Droop”.

Black Starting Closing the generator breaker when no other generator is supplying
power to devices on the local bus is referred to as a black start. In
such cases, the turbine should be started with all Util inputs cleared
and an Isoch input set. The operating state will then display as
“Spd/Isoch” to indicate the controller will stay in its isochronous
mode even if the generator breaker is closed. Closing that breaker
would change the operating state display to “Isoch”.
A heavy electrical load might then cause the turbine speed and bus
frequency to drop significantly. Because frequency variations can
damage some types of electrical equipment, your installation may
include protective devices that will trip the turbine if the Speed Con-
troller fails to maintain an acceptably stable speed. If that happens,
you should reduce the electrical load before attempting a restart.

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44 Chapter 2: Operation

Manual Automatic positioning of the throttle valve can be overridden by

selecting manual operation or asserting a remote manual input:
Operation • When manual operation is selected (see below), momentarily
pressing the Raise or Lower key changes the intended valve
position (IVP) 0.1 percent, while holding either down changes it
at a steadily increasing rate. That signal can also be ramped up
or down by asserting any OutUP or OutDN discrete input, or set
directly via the Manual Target register or Manual_TargetW vari-
able. It can be monitored via the OUT readout, an analog output
assigned the Act function, the OUT Display register, or the OPC
Out_Display variable.
• If a Remote Manual discrete input is asserted while the turbine
is running, the IVP will track a specified analog input. Automatic
operation will resume when that discrete input is cleared or if
that analog input fails.
Because the demand and physical clamps do not apply in manual,
you can adjust the valve to any position from zero to 100 percent
open. The local, remote, and cascade set points will track the actual
speed, in order to allow a bumpless return to automatic control.
The controller will temporarily resume automatic control if the speed
exceeds maximum governor (unless you have enabled an override
of this behavior, see Manual Override on page 105). The operator
can then help restore an acceptable speed by pressing the Lower
key to close the valve at a faster rate, but cannot use the Raise key
to retard valve closure. This condition triggers a “MOR active” alarm
and sets the MOR Active discrete and MOR_Active variable until it
is resolved.
If the speed remains in a critical range for more than a configured
number of seconds, a Critical Speed Stall (see page 39) is initiated.
If generator control is active and the generator breaker opens while
the controller is in manual, it will revert to automatic control and
either shut down the unit or switch to asynchronous control and
reduce the steam flow (see Breaker Fallback on page 101).

Selecting Manual If enabled, manual can be initiated any time the controller is operat-
Operation ing automatically and is not in its Tracking or Shutdown state. This
can be done by pressing the MAN key, asserting any discrete input
assigned the Man function, or clearing the Automatic coil or OPC
AutomaticW variable. The LED in that key will then light, any Man
relays activate (Auto relays de-activate), and the Automatic coil and
discrete and Automatic and AutomaticW variables are cleared.

The controller cannot be switched to Manual control while an ESD

Note: discrete is active or the ESDae input is True.

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 Series 3++ Speed Controller 45

Restoring Automatic operation can be restored by pressing the AUTO key,

Automatic asserting a discrete input assigned the Auto function, or setting the
Automatic coil or OPC AutomaticW variable. The LED in that key will
then light, any Auto relays activate (and Man relays de-activate),
and the Automatic coil and discrete and OPC Automatic and Auto-
maticW variables are set. If the speed is above minimum governor,
the Run state is selected (and that LED is lit). If not, the Idle state is
selected (but the Idle LED is not lit). If there are no valid speed
inputs, the Ready state is selected.
Bumpless transfer techniques are used to prevent any sudden
change in the intended valve position regardless of which set point
is selected:
• If the speed control response is outside the range of the
demand clamps, those clamps are not enforced until normal
control actions move the valve back within its clamped range.
• If the local set point is selected, its initial value will equal the tur-
bine’s speed at the time of the transition (or the minimum control
speed if below that threshold).
• If the remote set point is selected and the speed is above mini-
mum governor, that set point is ramped from the current speed
to the value from the remote source.
• If the cascade set point is selected and the speed is above min-
imum governor, that set point is initialized to the current speed.
If the performance set point has been set up to track its control
variable when the cascade set point is not being used, the initial
error will be zero when cascade control is restored. Otherwise,
that loop’s error is ramped from zero to the actual deviation.
• If either the remote or cascade set point is selected and the
speed is below minimum governor when automatic operation is
restored, the speed control loop will continue using its local set
point and the Remote or Cascade LED will flash. If the operator
then increases the local set point until the speed exceeds mini-
mum governor, the speed control loop will switch to using the
selected set point and the corresponding LED will quit flashing.
To avoid sudden changes in the speed control response, the
cascade set point is initialized to the current speed, while the
remote set point is ramped from that speed to the value from the
designated source.

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46 Chapter 2: Operation

Tracking State If one Speed Controller has been installed as an on-line “hot”
backup to another (see Redundant Tracking on page 76), it will use
serial communications to track the outputs and states of that active
controller whenever its own D1 discrete input is cleared.
In a typical redundant system, paired Speed Controllers are inter-
connected via a Redundant Control Selector (RCS) that monitors
their fault relays, controls their D1 inputs, and connects the control
valve actuator to the selected controller’s analog output. If the main
controller’s fault relay de-activates, the RCS automatically transfers
control of the governor valve to the backup controller (provided that
it has not faulted as well). The backup’s state and output signals will
initially duplicate those last received from the main controller.
The RCS also indicates which controller is active by lighting its
green MAIN or red BACK-UP LED, and the active controller can be
manually selected by pressing the Switch to Back-Up or Switch to
Main push-button.

The RCS will not automatically return control of your process to the
main controller after a fault is cleared (this must be done manually)
Note: and will never automatically or manually transfer control to a control-
ler that appears to have failed.

An inactive Speed Controller lights its Tracking LED, displays its

operating state as “Tracking”, and set its Modbus Tracking discrete
bit and OPC Tracking variable. It monitors and duplicates the set
point mode, power demand, intended valve position, and perfor-
mance set point of the active controller, so its other LEDs (except
Fault) will duplicate those of the main controller. Manual operation
can only be initiated from the active controller.

An inactive controller will light its ESD LED whenever any of its ESD
inputs are asserted, even if its Run, Idle, or Stop LED is also lit to
Note: indicate the active controller is not shut down. Switching to the inac-
tive controller would then initiate an emergency shutdown.

A tracking controller will generate only I/O-type alarms (analog input

failures, for example) that might indicate a reduced ability to control
the turbine. This minimizes duplicate alarms that must be separately
acknowledged and reset from each controller’s Front Panel.
Each controller’s “RS24V Fail” alarm, RS24 relays, RS 24V Fail dis-
crete, and RS_24V_Fail variable usually indicate the status of one of
the two possible RCS power inputs (see Power Supply Failures on
page 48). Both controllers would indicate such failures only if both
power supplies failed, in which case the switching relays would de-
activate and connect the switched signals to the main controller
even if it was indicating a fault. Restoring power would reselect the
controller that was active when power was lost.

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 Series 3++ Speed Controller 47

Controller This section tells how to monitor the health of the controller and its
connected field devices:
Health • In addition to CPU/IO and Auxiliary PCB Faults, which are indi-
cated via the Fault LED and relays, the controller can use LEDs,
control relays, and HMI variables to indicate Speed Input Fail-
ures, Transmitter Failures, Output and Valve Position Failures,
Serial Communication Errors, and Power Supply Failures.
Many of these conditions also light the Alarm LED, are indicated
via the status screen’s Alarms Menu (see DS3307/O), activate
any Alarm relays, and set the Modbus Alarm discrete and OPC
Alarm variable.
Setting the Ready Modbus coil (00023) while the controller is
not in the Shutdown State will clear all alarms.
If the controller is sealed in an explosion-proof enclosure,
alarms can be displayed and acknowledged by asserting Menu,
Scroll, and Reset discrete inputs (see page 68).
• Various internal conditions and the values of the field inputs and
outputs can be monitored from the front panel and via computer
communications.

CPU/IO and The CPU/IO PCB has a watchdog timer that must be regularly reset
Auxiliary PCB by the control program. Otherwise, its fault relays are de-activated
Faults and its CPU is reset, thus restarting the control program:
• If the fault was triggered by a software error, the reset would
clear the watchdog timer and re-activate the fault relays. The
Engineering Panel would then beep and display “Reset”, the
Reset discrete and Reset variable would be temporarily set, and
the CPU Reset Count [MODE TEST 6] would increment. Thus,
frequent resetting and a high reset count generally indicates a
software problem that should be reported to CCC.
• If the CPU or RAM/clock chip or a power converter failed, the
fault relay would remain de-activated and (if possible) the front
panel would light its Fault LED, display “No Comms with Main
CPU” on its status screen, and turn all other display elements
off. The controller should be immediately disconnected from the
controlled process and then replaced.
If a fault relay is assigned a second function (see Fault Relays on
page 69), that condition will light any LED or indicate any alarm
associated with it, but will not trigger a reset or light the Fault LED.
The Auxiliary PCB also has a watchdog timer that is regularly reset
by its CPU as long as it is communicating with the main CPU. If it
times out or the board fails, the CR9 fault relay will de-activate.
The main CPU will light the Fault LED when it cannot communicate
with the Auxiliary board, but all other display elements will continue

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48 Chapter 2: Operation

to operate. It will also display an “Aux. Board” alarm, set the Modbus
Aux Board Fail discrete and OPC Aux_Board_Fail variable, and
activate any general failure relays if such a communication failure
lasts for four consecutive scans (160 ms).
The main CPU will also increment the Auxiliary PCB Error Count
[MODE TEST HIGH] during each scan in which it fails communicate
with the Auxiliary PCB (and thus cannot read the speed inputs and
update the high-current output). Although an occasional such error
is not serious, a Speed Controller will initiate an Emergency Shut-
down (see page 39) if the error persists for eight consecutive scans.

If any Fault relay is de-activated, the controller’s analog output will

be unpredictable and should be immediately disconnected from the
Caution: final control element (the connected circuits often include a relay
that does so automatically).

Internal The internal temperature and power supply voltages displayed by

Conditions the Diagnostic Menu (see DS3307/O) can also be monitored via:
• the Board Temp, 24V Power, 15V Power, 5V Power, 3.3V
Power, and 1.2V Power Modbus registers; or
• the Board_Temp, 24V_Power, 15V_Power, 5V_Power,
3V_Power, and 1V_Power OPC variables.

Power Supply The failure of the power supply for or any power converter on the
Failures CPU/IO PCB is signaled by indicating a “Pwr Supply” alarm, ener-
gizing any PSF relays, and setting the Modbus Low Voltage discrete
and OPC Low_Voltage variable. The specific problem can be deter-
mined by comparing the power measurements (see above) to the
minimum voltages listed in Table 6-1 of UM3300/H
Unlike the voltages that power the controller’s internal circuits, that
of the external transmitter power circuit (which also powers the stan-
dard analog outputs) is not internally measured. However, it can be
monitored by a discrete input that has been assigned the FD Power
(-FD24) function. Clearing that input would then trigger an “FD24V
Fail” alarm, activate any FD24 relays, and set the FD 24V Fail dis-
crete and FD_24V_Fail variable. Also refer to 24 Vdc Power Tests in
Chapter 3.
In redundant systems, the failure of a redundant control selector
power supply is signaled by indicating an “RS24V Fail” alarm, ener-
gizing any RS24 relays, and setting the RS 24V Fail discrete and
RS_24V_Fail variable (see page 46).

Battery Failure For Rev B and higher CPU boards only, a “LowBattery” alarm indi-
cates low battery voltage has been detected on the RTC/RAM chip.

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 Series 3++ Speed Controller 49

If the internal battery fails on a Series 3++ Speed Controller, the real-
time clock will stop working and the controller will lose the ability to
time stamp entries in the Shutdown Log.

Speed Input In addition to the selected speed that is displayed by the RPM read-
Signals out and reported by the Modbus RPM Display register and OPC
RPM_Display variable, the value of each enabled speed input can
be viewed via the In/Out Menu (see DS3307/O) or monitored via the
Modbus MPU # registers and OPC MPU# variables.

Speed Input Failures Whenever one or more speed inputs is beyond its valid range (see
MPU Tests on page 83), the controller indicates an “MPU# Fail”
alarm (where # is the input number) and sets the corresponding
Modbus MPU # Fail discrete and OPC MPU#_Fail variable.
If all of the enabled speed inputs failed, any General Failure (Fail)
relays would be activated (thus triggering a switch to a redundant
controller) or the turbine would be shut down (simplex systems).

Analog Input The process measurements and other control signals that can be
Signals obtained via analog inputs are listed in Table 3-1 on page 56:
• The percent-of-span values of their Signal Variables (see page
57) can be monitored via the Modbus Channel # registers and
OPC CH# variables, or checked by executing the engineering
panel Input Signal Values [MODE TEST 4].
• The engineering units values of their Measured Variables (see
page 57) can be viewed via the front-panel status screen’s
Analog In Menu (see DS3307/O) and monitored via the OPC
CH#_scaled variables.

Transmitter Failures Whenever one or more analog inputs is beyond its valid range (see
Transmitter Testing on page 56), the controller indicates a “Tran#
Fail” alarm (where # is the channel number), activates any Transmit-
ter Failure (Tran) relays, and sets the Modbus Tran Fail discrete and
OPC Tran_Fail variable. All failed input(s) can be identified by scroll-
ing through the Analog In Menu (see DS3307/O), executing the
Transmitter Status Test [MODE:D ANIN –] from the engineering
panel, or monitoring the Modbus Tran Fail # discretes and OPC
CH#_fail variables.

Analog Output The intended and measured values of the Analog Outputs (see
Signals page 59) can be viewed via the In/Out Menu (see DS3307/O) or
monitored via the Modbus OUT Display, OUT1 Readback, OUT 2,
OUT2 Readback, OUT 3, and OUT3 Readback registers or the OPC
Out_Display, OUT1_Readback, OUT2, OUT2_Readback, OUT3,
and OUT3_Readback variables.

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50 Chapter 2: Operation

Output and Valve The Speed Controller offers two valve position tests, either of which
Position Failures will set any Output Fail (OutF) and General Failure (Fail) relays:
• If the controller detects a failure of its high-current output (see
Output Loopback Test on page 61), it will indicate an “Output-
Fail” alarm and set the Modbus Output Fail discrete and OPC
Output_Fail variable.
• If the controller detects a failure of the valve actuator by monitor-
ing an analog actuator pressure or position input (see Valve
Position Test on page 106), it will indicate an “PosFeedbck”
alarm and set the Modbus Position Fail discrete and OPC Posi-
tion_Fail variable.

Discrete I/O Their current states of the discrete inputs and intended states of the
Signals control relays can be viewed via the front-panel status screen’s
In/Out Menu (see DS3307/O):
• The discrete inputs can be used to trigger the control features
listed in Table 3-4 on page 65. Modbus hosts and OPC clients
can monitor those features via the DI Condition discretes and
DI# variables.
• The control relays can be set to indicate the process and control
system conditions listed in Table 3-5 on page 71. Modbus hosts
and OPC clients can monitor those conditions via the CR State
discretes and DO# variables.

Serial A hardware-level serial communication error occurs when a control-

Communication ler is unable to decode a data byte arriving at any serial port. Such
Errors an error is indicated by a beep and an identifying Engineering Panel
message, as described in Chapter 2 of UM3300/H. Because the
protocols used by Series 3++ Controllers reject faulty messages
(and usually provide for their retransmission), isolated hardware-
level errors rarely affect the operation of a controller.
A control-level serial communication error occurs when a controller
fails to receive certain expected transmissions via Port 1 or Port 2:
• Port 1 errors trigger a “Com1 Error” alarm and set the Modbus
Port 1 Fail bit and OPC Port1Fail variable. This would indicate
the controller failed to receive:
• decoupling data from its companion Extraction Controller,
• a configured serial remote set point from a Performance or
Dual-Loop A/P Controller, or
• redundant tracking data from its active peer.
Controllers whose transmissions are not being received can be
identified by executing the Serial Port 1 Test [MODE COMM –
3]. That procedure will display the status of controllers that are

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 Series 3++ Speed Controller 51

transmitting will display as “Good”, while the status of those

whose transmissions are not arriving will display as “Bad”.
• Speed Controllers do not use Port 2, and thus never set their
Modbus Port 2 Fail bit or OPC Port2Fail variable.

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 Series 3++ Speed Controller 53

UM3307 Series 3++ Speed Controller

Chapter 3 Input/Output Features

This chapter tells how to configure the analog and discrete inputs
and outputs and serial communication ports.

Field Input Module

Field Output Module

Figure 3-1 Field Termination Assemblies

Hardware Speed Controllers always employ the turbine controller hardware

configuration (see Chapter 1 of UM3300/H), which includes the Aux-
Options iliary PCB Assembly and provides:
• three magnetic-pickup Speed Inputs (MPU1 to MPU3),
• eight standard Analog Inputs (CH1 to CH8) and internal inputs
that read the controller temperature and power supply voltages,
• one High-Current Output (OUT1) and two Standard Analog Out-
puts (OUT2 and OUT3),
• sixteen Discrete Inputs (DI1 to DI16),
• nine Control Relays (CR1 to CR9),
• one linear variable differential transformer position input
(LVDT1) for the optional positioning loop, and
• four Serial Ports (Port 1 to Port 4).
The Auxiliary PCB provides the MPU inputs, OUT1, DI9 to DI16,
CR9, and LVDT1. All other I/O circuits and the serial ports are pro-
vided by the CPU/IO PCB.
The wiring terminals for those circuits can be located either on the
back panel or two separately-mounted field termination assemblies

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54 Chapter 3: Input/Output Features

(FTAs) known as the Field Input Module (FIM) and Field Output
Module (FOM):
• The FIM and FOM collectively provide wiring terminals for all
possible I/O circuits. Each is connected to the controller back
panel by a high-density interconnect cable (HDIC).
• When FTAs are not used, the back panel provides terminals for
all of the speed inputs, analog outputs, and serial ports, but only
four analog inputs (CH1 to CH4), eight control relays (all except
CR8), and nine discrete inputs (D1 to D9).

CPU and The firmware for the CPU and Auxiliary PCB microprocessors are
Auxiliary PCB occasionally upgraded to provide added or improved functionality.
Firmware Thus, when updating a Speed Controller’s software, it might also be
necessary to replace the firmware on either board. The Program
Version [MODE TEST 2] test will reveal which versions of the FPGA
and Speed board firmware are currently installed.

Disabling Input As an aid to developing and demonstrating Series 3++ Speed Con-
Signals trollers, they have several parameters that configure them to ignore
various input circuits:
• If the CPU Inputs Lockout [MODE:D LOCK 6] is enabled, the
controller ignores its analog inputs and discrete inputs 1 to 8.
• If the Auxiliary I/O Lockout [MODE:S LOCK 6 1] is enabled, the
controller ignores all of the inputs provided by its Auxiliary PCB
Assembly, including the speed inputs, position inputs, and dis-
crete inputs 9 through 16.
• If the Speed Inputs Lockout [MODE:S LOCK 6 2] is enabled and
LOCK 6 1 is Off, the controller ignores its speed inputs but will
read the other inputs provided by its Auxiliary PCB.
For an installed controller, these features have no legitimate use.
When configuring or testing your controller, you should thus verify
that all MODE LOCK 6 parameters are set to Off.

An installed Speed Controller should never be operated with any

Caution: LOCK 6 parameter enabled.

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 Series 3++ Speed Controller 55

AN IN OFF AN IN ON
(e.g., 0 to 10 V) (e.g., 4 to 20 mA)
CH (V) CH (mA)

Sampling Sampling
Hardware Hardware

Failed if: Failed if:

þ< AN IN LOW or AD (%) þ< AN IN LOW or AD (%)
þ> AN IN HIGH þ> AN IN HIGH

SV = 1.25 •
SV = AD (AD - 20%)

MODE TEST 4 SV (%) MODE TEST 4 SV (%)

MV = Min + MV = Min +
(Span · SV) (Span · SV)

MV MV

Figure 3-2 Analog Input Signal Processing

Analog Inputs Each Series 3++ Controller is equipped with eight analog inputs. As
described in the Analog Input Switches and FIM Analog Input Cir-
cuits section in Chapter 3 of , they are set for either 5 Vdc or 20 mA
operation by setting switches on the CPU/IO PCB Assembly or
installing resistors on the Field Input Module.
In this manual, we will refer to both the input circuits and the associ-
ated analog signals as Channels 1 through 8 (CH1 to CH8) — the
meaning in each case should be clear from its context.
The initial processing of these inputs and the terms used to distin-
guish their various intermediate values are illustrated by Figure 3-2:
Step 1: The raw analog inputs are converted to equivalent digital
values called Analog-to-Digital Variables (AD1 to AD8).
Step 2: Transmitter Testing compares each AD variable to its own
individual alarm limits.
Step 3: The AD variables are converted into percent-of-range Signal
Variables (SV1 to SV8).
Step 4: The signal variables are independently scaled to obtain the
Measured Variables (MV1 to MV8) displayed by the front-panel
status screen’s Analog In Menu (see DS3307/O).

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56 Chapter 3: Input/Output Features

Analog-to-Digital The input circuitry converts the analog input signals into equivalent
Variables digital values for use by the CPU. Each signal is passed through a
hardware filter to remove unwanted high frequency components,
and a windowing filter that samples each signal several times per
scan cycle and reports the resulting average.
Because these values are generated by an analog-to-digital con-
verter, we refer to them as analog-to-digital variables (AD1 to AD8).
They are reported to the CPU as percentages of the analog signal’s
full-scale value. For example, a 20 mA signal would be reported as
100 percent, while 4 mA would be reported as 20 percent.

Transmitter The controller determines whether or not each analog input is valid
Testing (see Transmitter Failures on page 49) by comparing its AD variable
to the corresponding Analog Input Low Alarm Limit [MODE:D ANIN
# LOW] and Analog Input High Alarm Limit [MODE:D ANIN # HIGH]
parameters. If CH2 was a 4 to 20 mA current-loop, for example, set-
ting AN IN 2 LOW to 15.0 percent would set its lower limit to 3.0 mA.
Because an analog input can never be higher than 102.4 (A2.4) nor
lower than 00.0, setting ANIN HIGH and LOW to these values has
the effect of disabling that channel’s transmitter alarm test. Using
these values for unused inputs prevents them from interfering with
the proper operation of this feature.
If ANIN HIGH is set to 102.3 (A2.3), a transmitter failure is indicated
only if the signal reaches the 21.0 mA NAMUR NE 43 smart trans-
mitter high threshold.

Table 3-1 Potential Analog Input Signals

Signal Input Reference

Performance
CH1 Performance Control Variable (see page 90)
Control Variable
Remote Manual
CH2 Remote Manual (see page 105)
Output Target
Generated Electrical
CH3 Megawatt Droop (see page 99)
Power
Valve Position CH4 Valve Position Test (see page 106)
Remote Load Limit CH6 Load Limits (see page 98)
Remote Set Point assigned Analog Remote Set Point (see page 88)

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 Series 3++ Speed Controller 57

Signal Variables Each analog-to-digital variable is then converted to a percent-of-

range signal variable according to whether or not the corresponding
transmitter uses an offset zero (for example, 4 to 20 mA or 1 to 5
Vdc). Signals that are so offset are scaled as:
SV = 1.25   AD – 20 percent 
Otherwise, the signal variable is set equal to the analog-to-digital
variable (AD). In either case, the SV values are constrained to the
range 00.0 to 100.0 percent. Higher values are changed to 100.0,
lower values to 00.0. You can use the Input Signal Values [MODE
TEST 4] key sequence to directly examine these signal variables
from the Engineering Panel.
Any signal that has an offset zero (for example, a 4 to 20 mA input)
must be identified by enabling the corresponding Offset Zero Input
[MODE:D ANIN #]. Signals that are not offset are identified by dis-
abling the corresponding parameter.

Measured The status screen’s Analog In Menu (see DS3307/O) displays

Variables selected signal variables, labelled and scaled to appropriate units of
your choosing. For example, you might display the governor valve
pressure signal as:

1:V1 Press
250. psig

The available variables are defined and scaled by the five Measured
Variable [COND:D DISPLAY 0] parameters for each analog input.
For example, the DISPLAY 0 1 parameters govern the display of
signal variable SV1:
• Each Measured Variable Display [COND:D DISPLAY 0 #]
parameter defines whether the corresponding variable can be
viewed (SV1 can be displayed only if DISPLAY 0 1 is On).
• Each Measured Variable Name and Units [COND:D DISPLAY
0 # –] parameter defines the name shown above and engineer-
ing units that will follow the numeric value of the input. Each
name can consist of any eight symbols from Table 3-2, the units
can consist of any five.
• Each signal variable’s Measured Variable Minimum [COND:D
DISPLAY 0 # LOW] defines the digits shown when it is zero, its
Measured Variable Maximum [COND:D DISPLAY 0 # HIGH]
defines the digits shown when it is 100 percent, and its Mea-
sured Variable Decimal [COND:D DISPLAY 0 # •] defines the
decimal point position. Mathematically, this can be stated as:
n dec
MV =  Min +  SV    Max – Min    10
where nSV is the signal variable’s normalized value.

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58 Chapter 3: Input/Output Features

If cascade or limiting control is enabled, its control loop PV and SP

readouts (and OPC variables) employ the scaling defined for CH1
even if its Analog In Menu display is disabled. Similarly, the droop
control PV and SP readouts and OPC variables employ the scaling
defined for CH3 even if its Analog In Menu display is disabled or
CH3 is not used to measure the generated power.
Because the decimal point is a character that requires one of the
four display positions, only three digits can be displayed unless that
parameter is disabled (Off). In other words, that parameter identifies
the digit the decimal will replace (it and all less-significant digits are
shifted one position to the right). A value of one corresponds to the
right-most, least-significant digit; four corresponds to the left-most,
most-significant digit. If DISPLAY 0 1 HIGH was 3210, for example,
the five possible values of DISPLAY 0 1 • would yield the following
values when SV1 was 100 percent:
0: 3210 1: 321. 2: 32.1 3: 3.21 4: .321
To obtain the most precise possible readouts, you should always
make the DISPLAY HIGH parameters as large as possible. For
example, to display three digit numbers from 0 to 600, set DISPLAY
HIGH to 6000 and DISPLAY • to 1 (for a trailing decimal). This will
give more precise readouts than you would get by setting DISPLAY
HIGH to 0600 and DISPLAY • to 0.
When entering these parameters from the Engineering Panel, the
DISPLAY 0 # • key sequence lets you to try as many different values
as you want. Press ENTER when you see the desired format.

Table 3-2 Available Symbols For Measured Variable Names and Units

Î Í Ì ± ¥ Ò space ! " # $
%&'()*+,-./
0123456789:;<=>?
@ABCDEFGHIJKLMNO
PQRSTUVWXYZ[\]^_
`abcdefghijklmno
pqrstuvwxyz

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 Series 3++ Speed Controller 59

Analog Outputs The Speed Controller has three analog outputs:

• OUT1 can be set up to manipulate any valve actuator requiring
a uni- or bipolar current-loop control signal of up to 200 mA. It is
thus referred to as the High-Current Output (see page 60). This
output and its readback circuit can be calibrated in the field.
• OUT2 and OUT3 are precision, 4 to 20 mA current-loop outputs
that do not require or allow field recalibration (see Standard
Analog Outputs on page 61).
Each is configured to convey the value of one of the variables listed
in Table 3-3 by setting its Output Assigned Variable parameter:
• If the governor valve requires a 4 to 20 mA control signal, it can
be connected to any Act output. If it requires a bipolar or higher-
maximum current it must be connected to OUT1.
• Outputs that are not used to manipulate the governor valve can
be used to drive remote display devices (for example, LED bar
graphs or digital readouts) for their assigned variables.
The intended and internal loopback values of each output signal can
be viewed via the status screen’s In/Out Menu (see DS3307/O):

In/Out In/Out
Out1 =##.# RdBk1=##.#
Out2 =##.# then RdBk2=##.#
Out3 =##.# RdBk3=##.#

If enabled, an output failure alarm is triggered only by an excessive

readback deviation of the high-current output (see Output Loopback
Test on page 61). Any open circuit’s reading will be zero. Loopback
readings can also be affected by power supply problems.

Table 3-3 Available Analog Output Assigned Variables

Code Output Signal

Act Any intended position of control valve Actuator
ActL 1 Act, plus Output Loopback Test
ActP 1 ActL plus Valve Position Test
None, Off 1 signal is zero
RmSP 2 or 3 Remote Set Point for the speed control loop
SP 2 or 3 selected Set Point for the speed control loop
Spd 2 or 3 rotational Speed from selected speed input

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60 Chapter 3: Input/Output Features

Unipolar Output Bipolar Output

100% 100%

Output Output
to DAC to DAC
0% 0%
0% Control Signal 100% 0% Control Signal 100%

On On
Phase Phase
Inverter Inverter
Off Off

200 mA 200 mA

Output Output
to to
Valve Valve

–200 mA –200 mA

Figure 3-3 Operation of Bipolar Output

High-Current OUT1 is set up to generate a maximum current of either 20, 60, or

Output 200 mA by setting two Auxiliary PCB jumpers, as described in the
Maximum Output Jumpers section in Chapter 3 of . That range can
then be further restricted and calibrated by setting the Output Scal-
ing Gain [COND:D GAIN 1] and Output Scaling Bias [COND:D
BIAS 1], as discussed in the Output Circuit Calibration section in
Chapter 4 of UM3300/H. Within the calibrated range, the resulting
current will be linearly proportional to the percent-of-range value of
the First Output Assigned Variable [COND:D OUT 1].
Its loopback measurement is similarly scaled and calibrated by set-
ting the Loopback Scaling Gain [COND:D GAIN 2] and Loopback
Scaling Bias [COND:D BIAS 2]. That procedure is discussed in the
Loopback Circuit Calibration section in Chapter 4 of UM3300/H.

CCC recommends using the Digital Positioning Module (DPM) (see

Valve Positioning on page 62 and Digital Positioning Module on
Note: page 63) for new project installations. Series 3 Plus to Series 3++
upgrades can continue to use the auxiliary PCB high-current output.

Bipolar Output OUT1 can be configured as either a unipolar (0 to maximum) or

bipolar (–max to +max) current loop by setting the Bipolar Output
[COND:D OUT 1 –] parameter:
• For 4-to-20 mA actuators, that parameter must be Off. The mag-
nitude of OUT1 is then calculated as shown in the top left panel
of Figure 3-3, and the phase inverter is never turned on.

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 Series 3++ Speed Controller 61

• If the actuator requires a bipolar signal, OUT 1 – must be On.

The magnitude of OUT1 is then calculated as shown in the top
right panel of Figure 3-3, and the phase inverter is turned on
whenever a negative current flow is needed.

Output Loopback If the First Output Assigned Variable [COND:D OUT 1] is set to ActL
Test or ActP, the controller compares its readback and intended values
and indicates an output failure (see Output and Valve Position Fail-
ures on page 50) if they differ by more than five percent (5.0%) of
span for a minimum time defined by the Output Failure Delay
[COND:D CONST 2].

Standard Analog The Second Output Assigned Variable [COND:D OUT 2] configures
Outputs OUT2 to convey the value of one of the variables listed in Table 3-3:
• If a speed variable is selected, the reverse parameter is usually
disabled. OUT2 will then increase from zero to 100 as the value
of that speed variable (in rpm) rises from the Second Output
Scale Minimum [COND:D OUT 2 LOW] to the Second Output
Scale Maximum [COND:D OUT 2 HIGH].
For example, assume the OUT 2 parameter is set to SP, REV 2
is Off, OUT 2 LOW is 2000 and OUT 2 HIGH is 6000. The OUT2
variable and signal would then be zero/4 mA when the speed
set point was at or below 2000 rpm and 100.0/20 mA when that
set point was at or above 6000 rpm.
• If any Act variable is selected and the Second Output Reverse
[MODE:D REV 2] is disabled, the OUT2 variable will equal the
intended valve position (IVP) and the current will rise from 4 to
20 mA as the IVP rises from zero to 100.0 percent. If the reverse
parameter is On, OUT2 will be the complement of the intended
position (OUT2 = 100% – IVP) and the current will rise as the
IVP decreases.
OUT3 is similarly configured by the Third Output Assigned Variable
[COND:D OUT 3], Third Output Reverse [MODE:D REV 3], Third
Output Scale Minimum [COND:D OUT 3 LOW], and Third Output
Scale Maximum [COND:D OUT 3 HIGH].

The Output Scale Minimum and Maximum parameters have no

Note: effect when an Act variable is assigned to the corresponding output.

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62 Chapter 3: Input/Output Features

Steady State Power Piston

Pilot Valve

Drain
Supply
Drain

Opening

Drain
Supply
Drain

Closing

Drain
Supply
Drain

Figure 3-4 Operation of Hydraulic Actuator Requiring External Positioner

Valve The actuators for some steam control valves position a pilot piston
that regulates the flow of oil into and out of a power piston, which in
Positioning turn opens or closes the control valve (see Figure 3-4). The control
signal to such an actuator thus regulates the rate at which it opens
and closes, rather than its actual position. A Speed Controller can
manipulate such a valve indirectly, using OUT1 to convey the
desired position to a Digital Positioning Module (DPM) and the Valve
Position Test to monitor its valve position output.

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 Series 3++ Speed Controller 63

Series 3++ Speed Controller

CH4 CR1 CR9 OUT1 ESD DI
4-20 mA 4-20 mA

Relay
CM-1-631-03 500 

±10 Vdc ±10 Vdc relay circuit

power sources
Pos SP are not shown
DPM Fault
LVDT Out

Relay

LVDT Servo

Figure 3-5 Connecting a DPM to a Simplex Speed Controller

Digital Positioning Our Digital Positioning Module (DPM) measures a control element’s
Module position using a linear or rotary variable differential transformer
(LVDT or RVDT) input, provides that measurement to and receives
its set point from an associated controller via bipolar 10 Vdc analog
signals, and positions the pilot valve as a function of their deviation.
The basic interface between a DPM and a Series 3++ Controller is
illustrated by Figure 3-5:
• Any one 4-to-20mA controller output is connected to a 500
resistor in parallel with the DPM’s set point input and configured
to convey the actuator control signal. A relay that breaks that
loop is included in the controller’s fault relay circuit, so the DPM
would detect an open circuit if the controller faulted.
• An ESD or ESDae discrete input is included in the DPM fault
relay circuit, so a DPM failure would trigger the controller’s
emergency shutdown response and close the governor valve.
• Optionally, CH4 can be set up as a 20 mA input and connected
to the DPM’s ±10 Vdc position output via a CM-1-631-03 Analog
Input Conditioning Module. If the first Output Assigned Variable
is set to ActP, the Valve Position Test will then monitor the valve
position reported by the DPM and indicate a positioning failure if
it deviates from OUT1 by more than five percent.
Duplex systems and other applications are described and detailed
information on the set up, configuration, and operation of DPMs can
be found in the DPM Digital Positioning System [UM8412].

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Discrete Inputs All Series 3++ Speed Controllers are equipped with sixteen discrete
input circuits. The FIM provides terminals for all of them, but control-
ler’s with back-panel wiring terminals support only DI1 through DI9.
The voltages above or below which each is asserted or cleared is
listed on the Series 3++ Turbine Controllers Hardware Specifications
[DS3300/T].
All discrete inputs have a hard-coded debounce time of two cycles
(10 msec). Any variation in a discrete signal must persist for this
time before the signal value will change to the new value.
Each input is assigned one of the Control Functions listed in Table
3-4 by setting its Discrete Input Assigned Function [COND:D IN ##].
If that parameter is given a positive value, the input is asserted by
raising its voltage above the minimum energized level. If that value
is negative, the input is asserted by lowering that voltage below the
maximum de-energized level.
For example, if DI1 is assigned the value +ESD, setting it would
initiate an emergency shutdown. If it is assigned the value -ESD,
a shutdown would be triggered by clearing that input.
The operation of each function is either momentary or latched.
Momentary functions execute as long as the associated input is
asserted. In contrast, latched functions are edge-triggered. This
means their functions are initiated when they are first asserted and
continue until canceled by another function. The input itself is then
ignored until it has been reversed, so continuing to assert a latched
input does not prevent its action from being counteracted from the
Front Panel, by another input, or via computer communications.
For example, if an input assigned the value +Remot is set, the
remote set point will be used until another set point is selected. Even
then, that particular input must be cleared before it can be used to
reselect the remote set point.
You can assign the same function to more than one input. If two or
more are assigned the Permissive (+Start) function, all of them must
be set before the turbine can be started. Any other function is initi-
ated when any associated discrete input is asserted.
The states of these inputs can be viewed via the front-panel status
screen’s In/Out Menu (see DS3307/O). Their assigned conditions
can be viewed by pressing the engineering panel COND and IN
keys, then pressing the decimal (•) key repeatedly.

Control Functions The controller’s discrete inputs can be used to start up or shut down
the turbine, select automatic or manual operation, switch between
the local, remote, or cascade set points, ramp the speed to user-
defined levels, manually vary the intended control valve position,

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 Series 3++ Speed Controller 65

select a generator control mode, select redundant tracking, or exe-

cute an overspeed trip test.

Table 3-4 Discrete Input Functions

Code Type (1) Function

anSSP M select Analog Remote Speed Set Point
Auto L select Automatic operation
Casc L select Cascade Speed Set Point
ESD M select ESD Mode
ESDae M triggers an ESD in any state; holds controller in shutdown
FD24 M triggers FD Power alarm
fD31 L indicate Load Loss
Gen M Generator Breaker is closed
Idle1 select Idle1 Mode
Idle2 L select Idle2 Mode
Idle3 select Idle3 Mode
Isoch M select Isochronous
Local L select Local Speed Set Point
Man L select Manual operation
Menu M selects next status screen Menu
Off — none
OStst M initiate OS Test
OutDN M Output Down (lower intended valve position)
OutUP M Output Up (raise intended valve position)
Rated L select Rated Mode
ReMan L select Remote Manual operation
Remot L select Remote Speed Set Point
Reset L Reset operating state or Reset alarm
RS24 M triggers RCS Power alarm
Run L initiates Startup
Scrol M Scroll to next screen of current status screen menu
SpdDN M Speed Down (lower local set point)
SpdUP M Speed Up (raise local set point)
Start M Start Permissive satisfied
Stop L select Stop Mode
1M = momentary, L = latched

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66 Chapter 3: Input/Output Features

Code Type (1) Function

Track M select redundant controller Tracking
TTvlv M Trip and Throttle valve is closed
Util M Utility Breaker is closed
1M = momentary, L = latched

In the following descriptions, the word assert means to set an input

assigned a positive function or clear one with a negative function.

Automatic or Manual Asserting any previously-cleared Automatic (Auto) input selects

Operation automatic operation, asserting a previously-cleared Manual (Man)
Automatic input selects manual, and asserting a previously-cleared Remote
Manual (ReMan) input selects remote manual:
Manual
• While operating in remote manual, the intended valve position
Remote Manual
(IVP) tracks the CH2 signal variable. Automatic operation will
resume if all such inputs are cleared or that analog input fails.
Output Down • While in manual, the IVP rises at a steadily increasing rate when
Output Up any Output Up (OutUP) input is asserted (it would take about 20
seconds to change from zero to 100 percent). Asserting any
Output Down (OutDN) input lowers the IVP in the same fashion.
These inputs are ignored when asserted at the same time.
Note: The controller cannot be switched to manual operation while
the ESDae input is True.

Speed Set Point The set point source for either the speed or electrical power control
loop can be selected via discrete inputs, depending on whether or
not Generator Control (see Chapter 6) is enabled.
Analog Remote Asserting a previously-cleared Remote (Remot) input selects the
Remote remote set point. If both an analog and a serial source are set up,
the analog source can be selected by asserting any Analog Remote
(anSSP) input and clearing all such inputs selects the serial source.
Local Asserting a previously-cleared Local input selects the local set point.
Speed Down The speed set point will then rise or fall at a configured rate when
any Speed Up (SpdUP) or Speed Down (SpdDN) input is asserted
Speed Up (if droop control is active, the power set point is adjusted accord-
ingly). The SpdUP and SpdDN inputs are ignored if asserted at the
same time.
Cascade Asserting a previously-cleared Cascade (Casc) input selects the
cascade speed or power set point.

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 Series 3++ Speed Controller 67

Operating State and If the controller is operating in its Shutdown state (Shutdown relays
Sequencing activated), you can select the Ready state by asserting any previ-
Reset ously-cleared Reset (Reset) input. Note: The controller cannot be
Reset while the ESDae input is True.
Startup If the controller is in its Ready state with all Permissive (Start) inputs
Permissive and no ESD Mode (ESD) inputs asserted, any Ready relays will be
activated. You can then initiate an automatic startup by asserting
any previously-cleared Startup (Run) input. The startup will termi-
nate when the turbine reaches the Idle1 Speed unless you first
asserted a different Operating Mode input.
Tracking If Redundant Tracking is enabled (see page 76), this controller will
track the operation of a companion Speed Controller as long as any
Tracking (Track) input is asserted. Best practice is to assign this
function to an input provided by the CPU/IO PCB (DI-1 through DI-
8), but not to an auxiliary PCB input (DI-9 through DI-16).

Operating Mode If the turbine is running, you can initiate any ramped sequence by
Idle1 Mode asserting the corresponding operating mode input:
Idle2 Mode • Asserting any previously-cleared Idle1 Mode (Idle1) input initi-
ates a ramp to the Idle1 Speed.
Idle3 Mode
• Asserting any previously-cleared Idle2 Mode (Idle2) input initi-
Rated Mode ates a ramp to the Idle2 Speed.
ESD Mode • Asserting any previously-cleared Idle3 Mode (Idle3) input initi-
Stop Mode ates a ramp to the Idle3 Speed.
• Asserting any previously-cleared Rated Mode (Rated) input initi-
ates a ramp to the Rated Speed.
• Asserting any previously-cleared ESD Mode (ESD) input initi-
ates an emergency shutdown.
• Asserting any previously-cleared Stop Mode (Stop) input initi-
ates a ramped shutdown.
ESDae Asserting the ESDae (always enabled) input initiates an Emergency
Shutdown in any operating state, including the Ready State. This
input forces the controller to stay in the Shutdown State. While this
input is active, the controller cannot be Reset or switched to Manual
Operation.
Load Loss In addition, you can initiate the load loss response (which selects
and initializes the local set point to the Default Set Point) by assert-
ing any previously-cleared Load Loss (fD31) input.

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68 Chapter 3: Input/Output Features

Generator Control In generator control applications, you can use Gen, Isoch, and Util
Generator Breaker inputs to select either Isochronous Control or Droop Control:
Utility Breaker • As long as all Generator Breaker (Gen) inputs are cleared, the
controller will operate in its isochronous mode.
Isochronous
• If any Gen and any Utility Breaker (Util) input are simultaneously
asserted, the controller will operate in the droop mode.
• If any Gen input is asserted and all Util inputs are cleared,
asserting any Isochronous (Isoch) input selects isochronous
control and clearing all Isoch inputs selects droop control.

Overspeed Trip Test If the Overspeed Trip Test [MODE:S fC 2] is enabled (On), any Test
OS Test Enabled (Test) relays will be activated. You can then raise the local
set point above Maximum Governor whenever any OS Test (OStst)
Trip and Throttle input is asserted. Any OS Enabled (OSen) relays will toggle on and
off when the Electronic Overspeed Trip limit (EOST) is exceeded.
If a TTvlv input is asserted when the trip and throttle valve closes,
the status screen can display the number of milliseconds it takes
that valve to close (see Overspeed Trip Test on page 114).

Front-Panel Many of the discrete input functions duplicate those of front-panel

Operation keys and buttons, thus providing a way to remotely operate certain
Menu features without allowing physical contact with the controller. In
particular, the status screen can be operated by asserting discrete
Scroll inputs assigned the Menu and Scrol functions, and displayed alarms
Reset can be acknowledged by asserting any Reset input.

24 Vdc Power Tests Unlike the voltages that power the controller’s internal circuits, that
FD24 of the external transmitter power circuit (which also powers the stan-
dard analog outputs) is not internally measured. However, it can be
RS24 monitored by a discrete input that has been assigned the FD Power
(-FD24) function. Clearing that input would then activate any FD
Power relays, trigger an “FD24V Fail” alarm, and set the Modbus FD
24V Fail discrete and OPC FD_24V_Fail variable.
Similarly, each Speed Controller in a redundant pair can use an
input assigned the -RS24 function to test and alarm the failure of
one of its Redundant Control Selector’s 24 Vdc power supplies (see
RCS Power Failure in Chapter 5 of UM3300/H). Clearing that input
would then activate any RCS Power relays, trigger an “RS24V Fail”
alarm, and set the Modbus RS 24V Fail discrete and OPC
RS_24V_Fail variable.

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 Series 3++ Speed Controller 69

Control Relays The controller’s relay outputs can be used to automatically trigger
alternate control measures or to control External Alarms for a variety
of process and controller conditions. The operation of each is set by
selecting one of the conditions from Table 3-5 as its Relay Assigned
Function [MODE:D RA #]. Except for the Fault Relays, each can
either activate or de-activate when that condition is detected:
• If its RA parameter has a positive value, the assigned condition
activates it.
• If that parameter is negative, that condition de-activates it.
For example, if MODE:D RA 3 is assigned the value +Rem and is
normally open, CR3 will be activated and its associated circuit will
be closed whenever the remote set point is selected. If it is given the
value –Rem, that condition would cause CR3 to de-activate.
Whether energizing a relay opens or closes its circuit depends on
the position of its NO/NC switch, as described in the CPU/IO Control
Relay Switches section in Chapter 3 of UM3300/H.
The states of these outputs can be viewed via the front-panel status
screen’s In/Out Menu (see DS3307/O). Their assigned conditions
can be viewed by pressing the engineering panel MODE and RA
keys, then pressing the decimal (•) key repeatedly.

Fault Relays Control relay CR1 is hard-wired as a main CPU fault relay (see
CPU/IO and Auxiliary PCB Faults on page 47), but can also be
assigned one additional function (General Failure, for example).
CR2 can be set to de-activate whenever CR1 does by setting a
switch on that assembly (its assigned function then affects only the
Modbus bit and OPC variable indicating its state). CR9 serves
exclusively as an Auxiliary PCB fault relay, and has neither an
assigned function parameter nor a Modbus discrete.

External Alarms You can use the relay outputs to control external indicators (lights,
horns, and so on) for any condition described below. However, set-
ting up and interpreting such an alarm can be confusing because
three different factors affect whether it indicates that the assigned
condition does or does not exist:
• If the assigned function is positive, any non-fault relay activates
when that condition occurs. Relays with negative functions will
de-activate when those conditions occur.
• The relay’s field wiring terminals can be internally connected to
its normally-open (energizing completes the circuit) or normally-
closed contacts (energizing opens the circuit).
• The alarm device itself may light or sound either when its control
circuit is completed, or when it is opened.

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70 Chapter 3: Input/Output Features

Relay Unless otherwise noted, the following descriptions assume each

Assignments alarm circuit is set up to indicate that its assigned condition exists:

Alarm The Alrm function indicates one or more alarm conditions have been
detected. In contrast to the Alarm LED, which remains lit or contin-
ues flashing until you have acknowledged and corrected all such
conditions, alarm relays remain set only until all such conditions
have been displayed and acknowledged via the front-panel status
screen’s Alarms Menu (see DS3307/O).
Always Set Relays assigned the +On function de-activate only if the controller
loses power, those with the -On function are always de-activated.
Fault Relays given the -On function never activate.
Automatic The Auto function indicates the controller is operating automatically.
Cascade The Casc function indicates the performance control loop is manipu-
lating the speed or electrical power set point.
Discrete Input The DGI function indicates the corresponding discrete input is
asserted (if assigned to CR3, that relay will report the state of DI3).
Droop The Drop function indicates the controller is regulating an electrical
generator’s power output. This relay can be active only during auto-
matic control in the Run State.
FD Power The FD24 function indicates a transmitter power test failure (see
page 68).
General Failure The Fail function indicates an unacceptable output loopback (see
page 61) or position feedback (see page 106) deviation, the failure
of all enabled speed inputs (see page 83), an auxiliary PCB failure,
or a low power supply or converter voltage. The -Fail function is
often assigned to Fault Relays.
Idle1 The Idl1 function indicates the turbine speed is between the Idle1
Speed and Idle2 Speed (if it is not zero) or Minimum Governor (if
Idle 2 is zero).
Idle2 The Idl2 function indicates the turbine speed is between the Idle2
Speed and Idle3 Speed (if it is not zero) or Minimum Governor (if
Idle 3 is zero).
Idle3 The Idl3 function indicates the turbine speed is between the Idle3
Speed and Minimum Governor.
Internal PSF The PSF function indicates a bad power supply or converter (see
the Internal Conditions section in Chapter 6 of UM3300/H).
Isochronous The Isoc function indicates the controller is regulating the speed and
frequency of a generator. This relay can be active only during auto-
matic control in the Run State.

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 Series 3++ Speed Controller 71

Limit The Limt function indicates the performance control variable is

beyond its limiting control threshold, or (extraction applications only)
the speed control response is at one of its demand clamps.
Manual The Man function indicates manual operation of the controller.
Never Set Relays assigned the +Off function are always de-activated, those
with the -Off function de-activate only if the controller loses power.
Fault Relays are often given the -Off function.
Output Fail The OutF function indicates an output loopback (see page 61) or
position feedback (see page 106) failure. Relays that have been
assigned this function remain set only until the problem is corrected.
OS Enabled The OSen function indicates an OS Test (OStst) input has been
asserted or the front-panel status screen is displaying a prompt for
the Overspeed Trip Test (see page 68), thus allowing the operator
to raise the speed set point above Maximum Governor. If the speed
then rises above the Electronic Overspeed Trip threshold (EOST),
relays given this function will toggle on and off.
OS Trip The Trip function indicates the turbine is shut down because its
speed exceeded the Electronic Overspeed Trip speed. The control-
ler must be reset before the turbine can be restarted.

Table 3-5 Control Relay Functions

Code Function
Alrm unacknowledged Alarm
Auto Automatic operation
Casc Cascade Set Point
Co0# Servo Relays controlled via Modbus/OPC
DGI corresponding Discrete Input set
Drop Droop operation
ESD recent Shutdown
Fail General Failure
FD24 FD Power failure (field device)
Idl1 Idle1 state
Idl2 Idle2 state
Idl3 Idle3 state
Isoc Isochronous operation
Limt Limit condition
Man Manual operation
NDev Speed Deviation

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72 Chapter 3: Input/Output Features

Code Function
Off Never Set
On Always Set

RCS Power The RS24 function indicates a discrete input assigned the -RS24
function is cleared (see page 68), as discussed under RCS Power
Failure in Chapter 5 of UM3300/H.
Ready The Rdy function indicates the turbine is stopped but the controller
is ready to start it up (all ESD inputs cleared, all Start Inputs set).
Redundant Tracking The Trck function indicates that redundant tracking is active (see
Redundant Tracking on page 76).
Remote The Rem function indicates the speed or power control loop is using
its remote set point.
Reset The Rst function is indicated for one second when the controller is
reset from its shutdown to its ready to run state.
Run The Run function indicates the speed set point is above Minimum
Governor and is not being ramped. It is generally the opposite of the
Stop function.
Servo Relays The Co01 and Co02 functions track the corresponding Modbus coils
(00001 and 00002).

Table 3-6 Control Relay Functions (continued)

Code Function
OSen OS Enabled
OutF Output Fail
PSF Internal PSF (power supply failure)
Rdy Ready
Rem Remote set point
RS24 RCS Power failure (redundant control selector)
Rst controller Reset
Run Run state
SD Shutdown state
SPtk Set Point Track
Stop not in Run state
Strt turbine Start
Swi1 Speed Switch 1

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 Series 3++ Speed Controller 73

Code Function
Swi2 Speed Switch 2
Test Overspeed Test Enabled
Tran Transmitter Failure
Trck Redundant Tracking active
Trip OS Trip

Set Point Track The SPtk function indicates the Speed Controller is unable to satisfy
its analog remote set point because of a limiting condition or the
selection of manual or local set point operation.
Shutdown The SD and ESD functions indicate the turbine is shut down. Both
functions are indicated when the controller enters its Shutdown state
(at the end of a stop sequence or the beginning of an emergency
shutdown). The SD function is indicated until the controller is reset,
while the ESD function is indicated for only five seconds.
Speed Deviation The NDev function indicates that the difference between the turbine
speed and its set point has exceeded the Deviation Alarm Threshold
for a specified number of seconds. Relays assigned this function will
remain set until the deviation falls back below that threshold and the
“Speed Dev” alarm is acknowledged.
Speed Switch The Swi1 and Swi2 functions indicate conditions defined by the con-
figuration parameters for the corresponding Speed Switches (see
page 80). An unlatched speed switch remains active only as long as
the speed is beyond its threshold. A latched speed switch remains
active until the corresponding alarm is acknowledged.
Start The STRT function is indicated for one second when the turbine first
reaches the minimum control speed.
Stop The Stop function is generally the opposite of the Run function. It
indicates the speed set point is not above Minimum Governor and/or
is being ramped. While manual operation is selected, stop relays are
active only if the speed has never been above that threshold.
Test Enabled The Test function indicates the parameter that enables the Over-
speed Trip Test (see page 68) is set to On, which means that test
can be initiated.
Transmitter Failure The Tran function indicates at least one analog input is not within its
transmitter testing range (see page 56).

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74 Chapter 3: Input/Output Features

Coordination (Port 1)

PV RPM PV

SP OUT SP OUT SP OUT

ALT LIMIT 2 LIMIT 3 CASC LIMIT POWER ALT LIMIT 2 LIMIT 3

Extraction Controller Speed Controller Performance Controller

Fault Fault Fault

Alarm Alarm Alarm

ACK MENU SCROLL ACK MENU SCROLL ACK MENU SCROLL

AUTO MAN ESD AUTO MAN ESD AUTO MAN

RESET

OP
MODE
SP
MODE  OP
MODE
SP
MODE  REMT
SP
LOCAL
SP 
TEST ENTER  TEST ENTER  TEST ENTER 
A # A # A #

Figure 3-6 Communication With Other Controllers

Serial Ports Series 3++ Controllers are equipped with four serial ports for com-
municating not only with other Series 3++ Controllers, but also with
host computers and supervisory control systems:
• Port 1 is used to circulate information between redundant con-
troller pairs and among the Series 3++ Controllers regulating a
single rotating equipment train. Speed Controllers use it to coor-
dinate their actions with companion Extraction and Performance
Controllers. Up to eight controllers (or redundant controller
pairs) can be connected to any one Port 1 network.
• Speed Controllers do not use Port 2, which other controllers use
to communicate load-sharing information.
• Ports 3 and 4 are used to communicate with Modbus RTU
hosts, including PCs running our software support programs
(such as the TrainTools Series 3 Plus OPC Server).
Although these features are automatically enabled when required by
the chosen controller features, it is necessary to set the ID Numbers
that identify the controller to other devices on these networks and
the baud rates and parity for several of the serial ports.

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ID Numbers Each Series 3++ Controller must be assigned both a Controller ID

Number [MODE:D COMM 0] and a Computer ID Number [MODE:D
COMM 0 •] by setting those parameters from the Engineering Panel:
• The Controller ID Number identifies it on Port 1. It must be
unique among all controllers (except backups) in that network.
• The Computer ID Number identifies it on Ports 2, 3, and 4. It
must be unique among all devices connected to any of those
networks.

Serial In order for two devices to successfully communicate, both must be

Communication set up to send and receive information at the same speed and in the
Formats same basic format (for example, number of bits per character):
• There are no configuration parameters for Ports 1 and 2.
• The Port 3 Baud Rate and Port 3 Parity [MODE:D COMM 3] can
be 4800, 9600, or 19.2k baud and odd, even, or no parity.
• The same options are available for the Port 4 Baud Rate and
the Port 4 Parity [MODE:D COMM 4].
Ports 3 and 4 both use one start bit, eight data bits, and one stop bit.

Modbus/OPC The Modbus interface can be used to monitor the operation of

Configuration the compressor and controller, directly or via the Series 3 Plus OPC
Server. The Port 3 Scaling [MODE:D COMM 3] and Port 4 Scaling
[MODE:D COMM 4] parameters specify the register values each
port would report for a variable equal to its normal maximum value:
• The 4000 option (which should be selected for connections to
TrainTools PCs) would report Max as 4000.
• The 4095 option would report Max as 4095
• The 64k setting would report Max as 64000.
When an attempt is made to write a value above the scaling maxi-
mum for a Modbus holding register, the request is ignored (rather
than setting the register to the maximum value).
If the Modbus Write Inhibit [MODE:D LOCK 2] parameter is set to
Off, a few controller variables can also be changed via computer
communication. Otherwise, the Write Inhibit discrete and OPC
Write_Inhibit variable will be set and hosts and clients will be unable
to affect the controller’s operation.

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76 Chapter 3: Input/Output Features

Redundant As described in Chapter 5 of the Series 3++ Hardware Reference

[UM3300/H], you can install one Speed Controller as an on-line “hot”
Tracking backup to another.
The main controller and its backup must have Redundant Tracking
[MODE:D fE 1] enabled and have the same Controller ID Number
[MODE:D COMM 0]. If they are also given the same Computer ID
Number [MODE:D COMM 0 •], Modbus While Tracking [MODE:D
LOCK 0] must be disabled. At least one input in each controller must
be assigned the Track function, and asserting any such input will
cause the controller to operate in its Tracking State (see page 46).
If you want Modbus masters to be able to determine which controller
is active, hardwire one of the main controller’s otherwise unused dis-
crete inputs so it is always asserted. The corresponding discrete
input bit will then be cleared only when the backup unit is active.
When redundant power supplies are provided for the redundant
switching device, each Speed Controller can use a discrete input to
test and alarm the failure of one of them (see page 68 and RCS
Power Failure in Chapter 5 of UM3300/H).

Switching The redundant switching device is usually triggered by the Fault

Conditions Relays (see page 69) of the main controller’s CPU/IO and Auxiliary
PCB Assemblies. Those relays (CR1 and CR9) are wired in series
and set up for normally-closed operation, so an automatic switch to
the backup controller will occur if either of them de-activates.
If CR1 is configured to indicate a condition from Table 3-5, either
that condition or a hardware fault will trigger a switchover. If you
want more than one of those conditions to initiate a transfer, assign
them to additional relays wired in series with CR1 and CR9.
The General Failure (Fail) relay function is particularly appropriate to
this purpose. It indicates one or more conditions (see page 70) that
could stem from either internal or external malfunctions, in which
case switching to the backup might allow continued operation. In the
event that all of the primary controller’s MPUs fail, it will delay the
resulting emergency shutdown for a fraction of a second to give the
General Failure condition time to trigger a switchover to the backup
controller.

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UM3307 Series 3++ Speed Controller

Chapter 4 Turbine Speed

This chapter tells how to configure the speed profile and inputs.

Maximum Control
Too Fast

Power Turbine Speed

Overspeed Trip
Maximum Governor

Normal Operating Range

Rated Speed

Control Range

Valid Speed Range

Minimum Governor

Idle 3

Critical Range 2 Excessive Vibration

Idle 2

Critical Range 1 Excessive Vibration

Idle1

Minimum Control

Control Threshold
MPUs Unreliable

Figure 4-1 Typical Turbine Speed Profile

Turbine Speed The automatic control features assume the operation of a steam tur-
bine is subject to the following limitations (see Figure 4-1):
Profile • The Valid Speed Range is the range of speeds that can be
reliably measured.
• The Control Range is the range of speeds within which closed-
loop control can be applied.
• The Normal Operating Range is the range of speeds within
which the turbine is normally operated.
• The Critical Speed Ranges are speeds at which the turbine will
vibrate harmonically and thus should not be operated. These
must lie outside the normal operating range.
• The Idle and Rated Speeds are speeds to which the controller’s
automatic sequences can ramp the turbine.

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78 Chapter 4: Turbine Speed

Valid Speed The minimum speed the controller can reliably measure, which
Range depends on the type of magnetic pickups used (see MPU Tests on
page 83) is set by the Control Threshold [COND:S ALARM 1].
Similarly, the Maximum Control Speed [COND:S DISPLAY HIGH]
defines the highest speed the controller can record (see Scaling and
Normalization on page 82). All speeds and parameters with rpm as
a dimension are internally represented as fractions of this speed.

When configuring the controller from the Engineering Panel, the

Maximum Control Speed must be set before any other level or rate
Note: parameter with an rpm value. If you later change this parameter, all
other rpm-based parameters must be adjusted accordingly.

Control Range The Speed Controller will use closed-loop control only when the
turbine is operating between the minimum control and electronic
overspeed trip (EOST) speeds.
The Minimum Control Speed [COND:S DISPLAY LOW] defines the
lower limit for closed-loop control:
• The start-up sequence opens the control valve until this speed
is reached, then initiates PID control.
• The stop sequence slows the turbine to this speed, then closes
the control valve.
The Electronic Overspeed Trip [COND:S LVL 5] speed defines the
maximum limit for closed-loop control. If this speed is exceeded, the
controller immediately initiates an emergency shutdown.

Do not use a Series 3++ Speed Controller as your turbine’s only

Warning! overspeed protection device.

The EOST should be set slightly below the turbine’s Mechanical

Overspeed Trip Speed (MOST), which is the speed at which it will
be mechanically tripped. You can determine your turbine’s MOST
using the Speed Controller’s Overspeed Trip Test (see page 114).

Normal Operating The turbine’s normal operating range is defined by its minimum and
Range maximum governor speeds, which set the normal limits for all of its
speed set points:
• Minimum Governor [COND:S SP LOW] should be the lowest
speed at which you would normally want the turbine to run.
• Maximum Governor [COND:S SP HIGH] should be the highest
speed at which you would normally want the turbine to run.

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Critical Speed Most turbomachinery trains have at least one critical speed at which
Ranges they will vibrate at a harmonic or resonant frequency. Operating a
turbine too close to one of these critical speeds will result in severe
damage. The Speed Controller’s Critical Speed Avoidance (see
page 111) features minimize the turbine’s operation within either of
two such ranges:
• The first is defined by the First Critical Speed Lower Limit
[COND:S LVL 8 LOW] and First Critical Speed Upper Limit
[COND:S LVL 8 HIGH].
• The second is defined by the Second Critical Speed Lower Limit
[COND:S LVL 9 LOW] and Second Critical Speed Upper Limit
[COND:S LVL 9 HIGH].
The first range must be below and cannot overlap the second, and
all four limits must be below Minimum Governor. To disable either
range, set both of its limits to zero.

Idle and Rated The Rated Speed [COND:S LVL 4] defines the speed at which the
Speeds start-up and loading sequences normally terminate (for generator
applications, it must equal the nominal synchronous speed). The
Idle1 Speed [COND:S LVL 3 1], Idle2 Speed [COND:S LVL 3 2],
and Idle3 Speed [COND:S LVL 3 3] define the target speeds for the
controller’s idle-up and idle-down sequences.
Although each of these parameters can be given any value between
zero (00000) and the Maximum Control Speed [COND:S DISPLAY
HIGH], unexpected results might result if the following guidelines
are not followed:
• The Rated Speed should be between Minimum Governor
[COND:S SP LOW] and Maximum Governor [COND:S SP
HIGH], inclusive.
• No idle speed should exceed Minimum Governor.
• The Idle1 Speed should be below the Idle2 Speed which should
be less than the Idle3 Speed.
Setting any of these parameters to zero (00000) disables the corre-
sponding set point ramps. If the Idle1 Speed is disabled, the Idle2
Speed should also be disabled. If the Idle2 Speed is disabled, the
Idle3 Speed should also be disabled.

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80 Chapter 4: Turbine Speed

Speed Switches You can configure the controller to generate a “SpdSwitch#” alarm
or trip a control relay if the turbine speed rises above or falls below
either of two threshold speeds. For example, you might want to set
up two alarms, one that indicates the speed is currently above maxi-
mum governor and one that indicates if it ever has been.
The operation of these switches are defined by the Switch 1 Mode
and Switch 1 Speed [COND:S SP 4] and Switch 2 Mode and Switch
2 Speed [COND:S SP 5] parameters. The former select one of the
following modes of operation, the later set the threshold speeds:
• If the high, latched mode (+Latch) is selected, an alarm is gen-
erated and any Swi# relays are set when the turbine exceeds
the switch’s threshold speed. Both will be cleared as soon as
the alarm has been acknowledged and the speed has fallen
below the threshold.
• If the low, latched mode (–Latch) is selected, an alarm is gener-
ated and any Swi# relays are set when the turbine falls below
the switch’s threshold speed. Both will be cleared as soon as
the alarm has been acknowledged and the speed has risen
above the threshold.
• If the high, unlatched mode (+NLatc) is selected, the Swi# relay
is set when the turbine exceeds its threshold speed and cleared
when it falls below the switch’s threshold. No alarm is
generated.
• If the low, unlatched mode (–NLatc) is selected, the Swi# relay
is set when the turbine falls below the switch’s threshold speed
and cleared when its rises above that threshold. Again, no alarm
is generated.
To prevent a speed switch relay from toggling on and off when the
speed is exactly at the specified threshold, the controller implements
a neutral zone approximately 4 rpm wide.
For example, if the Switch 1 Mode is +Latch and the Switch 1 Speed
is 7500 rpm, a “SpdSwitch1” alarm will be displayed and any Swi1
relays will be set if the speed rises above 7500 rpm. If the speed is
still above 7496 rpm when you acknowledge that alarm, it and the
relays will be cleared when NPT falls below 7496. If the speed is
below 7496, both are cleared immediately.
If that switch was unlatched, no “SpdSwitch1” alarm would be gen-
erated. Any Swi1 relays would be set when NPT rose above 7500
rpm and cleared as soon as it fell below 7496 rpm.

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 Series 3++ Speed Controller 81

Speed Gear

Magnetic Pickups
In/Out Menu

SPEED 1
Speed 2 Calculate RPM
Speed 3
Selected Speed Test Inputs:
labelled in all caps Selected Speed
Fail if below COND:S ALARM
For 3 MPUs, apply 2-of-3 voting Maximum Control Speed

Select Control Speed

3 Good: Use Median Signal
RPM Display 2 Good: Use High Signal Speed Control Loop
1 Good: Use Only Signal
None Good: Shut turbine down

Figure 4-2 Speed Input Signal Processing

Speed Inputs The Speed Controller measures the turbine’s speed by decoding
frequency signals from up to three magnetic pickups (MPUs). As
shown in Figure 4-3, each MPU is positioned near a balanced gear
on the turbine’s main or auxiliary shaft, and transmits a pulse to the
controller each time a gear tooth rotates past.

If at all possible, the speed gear should be mounted on the turbine’s

Note: main shaft.

You enable the speed input for each installed MPU by setting its
selection parameter to On:
MPU 1: Speed Input 1 [MODE:S ANIN 1]
MPU 2: Speed Input 2 [MODE:S ANIN 2]
MPU 3: Speed Input 3 [MODE:S ANIN 3]
If more than one MPU is enabled, the controller uses the following
rules to decide which one to use as the speed control variable:
• If there are three good input signals, the median speed is
selected.
• If there are two good input signals, the higher of those two
speeds is selected.
• If there is only one good input signal, that speed is selected.
• If all MPUs fail, an emergency shutdown (ESD) is initiated.

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82 Chapter 4: Turbine Speed

Turbine Auxiliary Shaft

Shaft

Speed Magnetic
Gear Pickup
Figure 4-3 MPU Signal Varies With Speed, Shaft Ratio, and Tooth Count

Scaling and The frequency of the MPU signals depends not only on the speed of
Normalization the turbine, but also on the number of teeth on the speed gear and
the ratio of the auxiliary and turbine shaft speeds. Thus, the follow-
ing function is used to calculate the turbine speed from the number
of pulses received during each scan:
N =  C  P  Rs   T
where
C= scan rate (scans per minute)
N= rotational speed (in rpm)
P= pulse count (pulses/scan)
Rs = Shaft Speed Ratio [MODE:S ANIN 6]
T= Gear Tooth Count [MODE:S ANIN 5]
Set the Gear Tooth Count equal to the number of teeth on the speed
measuring gear and the Shaft Speed Ratio equal to the number of
turbine revolutions required to rotate that gear once. For example,
AN IN 6 should be 1.000 if the gear is on the turbine’s main shaft. If
it’s on an auxiliary shaft that turns half as fast as the turbine, AN IN 6
should be 2.000.
In its internal calculations, the controller normalizes all rotational
speed values with respect to the Maximum Control Speed [COND:S
DISPLAY HIGH]. If that maximum is 10,000 rpm, for example, a
7500 rpm speed is internally represented as 0.750. This parameter
is usually set slightly higher than the trip speed for the turbine’s
primary (mechanical) overspeed protection device.

When configuring the controller from the Engineering Panel, the

Maximum Control Speed must be set before all other rotational
Note: speed parameters, all of which must be reentered if the normaliza-
tion speed is later changed.

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 Series 3++ Speed Controller 83

MPU Tests Two factors affect the minimum speed that can be read by the con-
troller’s frequency / magnetic pickup (MPU) inputs:
• An MPU signal frequency below 5 Hertz can not be read. The
corresponding minimum speed depends on the gear tooth count
and shaft ratio. For example, a 60-tooth gear mounted on the
main shaft would generate a 5 Hertz signal at 5 rpm.
• An MPU signal voltage below the minimum required by the
speed inputs can not be read. This is normally an issue only for
passive pickups (for which the voltage is a rising function of the
speed). If active (constant voltage) pickups are used, the con-
troller can measure any speed above that corresponding to a 5
Hertz signal. This can be determined by comparing the electrical
specifications of your MPUs to those listed on the Series 3++
Turbine Controllers Hardware Specifications [DS3300/T].
MPU failures are determined by comparing the speed from each
input to the Control Threshold [COND:S ALARM 1]. An input fails
this test if it is below that level.
If all three speed inputs are enabled, the highest and/or lowest will
also be considered to have failed if it has differed from the median
speed by more than a user-defined tolerance for at least eight con-
secutive scan cycles:
Median – Tol  N  Median + Tol
where
Median = median of the speeds calculated from the three inputs
Tol = MPU Tolerance [MODE:S ANIN 4]
A failure of either type generates an “MPU# Fail” alarm. If all of the
enabled speed inputs fail, the turbine is shut down. The failure of all
speed inputs will also activate any General Failure (Fail) relays and
(if Redundant Tracking is enabled) delay the resulting emergency
shutdown for a fixed fraction of a second. This would enable a
Redundant Tracking (see page 76) system to switch to the backup
controller if functioning MPUs tested bad due to a general failure of
the Auxiliary PCB.
For example, assume all three inputs are enabled and the tolerance
is 91 rpm. If MPU 1 indicates 3600 rpm, MPU 2 indicates 3650 rpm,
and MPU 3 indicates 3700 rpm, the acceptable speed range is 3650
± 91 (3559 to 3741) rpm. Because all three signals are in this range,
all three are judged to be valid. However, if the MPU 3 signal was
greater than 3741 rpm, an “MPU3 Fail” alarm would be indicated.

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 Series 3++ Speed Controller 85

UM3307 Series 3++ Speed Controller

Chapter 5 Speed Control

This chapter tells how to configure the speed and cascade/limiting
PID loops and explains how the control response is selected from
their actions.

General PID The following PID algorithm is used to calculate the speed and cas-
cade or limiting control responses:
Algorithm –
CR = CR P + CR I + CR I + CR D
100 100 Kr e
CR P = ----------  e CR I = ----------  ------  e  t CR D = Td  -------
PB PB 60 t
where:
CR D = derivative response
CR i– = accumulated integral from previous scan
CR I = integral response change
CR P = proportional response
t = scan time, in seconds
Kr = reset rate, in repeats/minute
PB = proportional band
Td = derivative coefficient, in seconds

Dead Zones It is highly unlikely that a turbine-driven process would ever reach a
true “steady-state” — minor perturbations and signal noise will
always combine to cause small fluctuations of its rotational speed
and power output. A control loop can be configured to ignore such
minor disturbances by defining a dead-zone bias (r1) for its con-
trolled variable. As shown in Figure 5-1, the PID error is calculated
by adding or subtracting this bias from the actual deviation:

 e + r1 e  – r1

e =  0 for – r1  e  r1

 e – r1 e  r1

This creates a dead zone around the set point, the width of which is
twice the value of r1.
The Speed Controller allows you to define dead zones for both the
speed and cascade control loops. The former is governed by the
Speed Dead-Zone Bias [PID:S r 1], while the latter is configured by
setting the PCV Dead-Zone Bias [PID:C r 1]. Setting either bias to
zero disables that loop’s dead zone.

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86 Chapter 5: Speed Control

e'

e
r1

Figure 5-1 Dead-Zone Error (E') as a Function of Actual Deviation

Speed Control The speed control loop responds to deviations of the turbine speed
from its set point:
Loop e = SP – N
where
e = deviation (normalized)
N = selected rotational speed (normalized)
SP = selected set point (normalized)
This loop’s PID action is governed by the Speed Proportional Band
[PID:S PB 1], Speed Reset Rate [PID:S Kr 1], Speed Derivative
Coefficient [PID:S Td 1], and Speed Dead-Zone Bias [PID:S r 1].

When setting these PID coefficients, remember that the speed and
Note: its set point are normalized relative to the Maximum Control Speed.

This loop’s PID coefficients can be further defined as functions of

the turbine speed (N) or intended valve position (IVP), as specified
by the Characterizer Argument [MODE:S SS 1]:
SS 1 On:PB = PB1 · f1 (IVP),Kr = Kr1 · f2 (IVP),r = r1 · f3 (IVP)
SS 1 Off:PB = PB1 · f1 (N),Kr = Kr1 · f2 (N),r = r1 · f3 (N)
where:
f1() = Proportional Band Characterizer [COND:S f(X) 1 #]
f2() = Reset Rate Characterizer [COND:S f(X) 2 #]
f3() = Dead-Zone Characterizer [COND:S f(X) 3 #]
Each of these characterizing functions is entered as ten numbers
that define its value at equally spaced percentages of the selected
argument (0, 11.1, …, 88.8, 100.0). Intermediate values of the char-
acterized coefficients are then calculated by linear interpolation.

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 Series 3++ Speed Controller 87

Speed Set Point As described under Speed and Set Point on page 26, the speed
control loop can use a local, remote, or cascade set point. The
remote set point can be manipulated by an analog input, companion
controller, or host computer. Regardless of its source:
• The selected set point’s normal range is defined by the Mini-
mum Governor [COND:S SP LOW] and Maximum Governor
[COND:S SP HIGH] parameters.
• Any remote set point is passed through a first-order-lag software
filter governed by the RSP Filter Time Constant [PID:S Tf 4].
• When a new source is selected, the set point is ramped to its
new target at the General Set Point Ramp Rate [PID:S G 1].
When generator control is enabled (see Chapter 6), the remote and
cascade set point can be selected only when droop control is active.
An analog remote set point’s signal variable would specify the
desired percentage of the generator’s maximum capacity.

Computer Set Point The methods used to vary the local and remote set points depend
on how the Computer Remote Set Point [MODE:D LOCK 8] is set:
• If LOCK 8 is On, the remote set point can only be changed via
computer communication and:
• Remote Set Point Reverse [MODE:D fE 3] is usually disabled,
• all changes are ramped at the General Set Point Ramp Rate
[PID:S G 1],
• any analog or serial source you have defined is ignored, and
• the local set point’s target value can only be ramped via the
front panel or discrete inputs.
• If LOCK 8 is Off, the local set point target can be varied via com-
puter communications, the front panel, or discrete inputs, but
the remote set point can only be manipulated by a companion
controller or an analog input.
The value of LOCK 8 can be read via the Modbus Computer RSP
discrete and OPC Computer_RSP variable.

Local Set Point The local set point’s target value will ramp up or down at the Local
Set Point Ramp Rate [COND:S SP 1] when the Raise or Lower key
is held down or a SpdUP or SpdDN input is asserted. If LOCK 8 is
Off, that target can also be set via computer communications. In
either case, the actual set point value will ramp toward the resulting
target at the General Set Point Ramp Rate [PID:S G 1].

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Serial Remote A Series 3++ Performance Controller can be defined as a remote set
Set Point point source by setting the Serial Remote Set Point [MODE:S fC 4]
equal to its Controller ID Number and disabling the Dual-Loop/ Per-
formance RSP [MODE:S LOCK 9]. If fC 4 specifies a Dual-Loop A/P
Controller, LOCK 9 must be enabled.
The Remote Set Point Reverse [MODE:D fE 3] should be given the
same value as the source controller’s CV1 Loop Reverse [MODE:P
REV 1], which should be set as if it has a signal-to-open valve. That
controller’s Display Output Reverse [MODE:P fD 1] should be Off.
The Remote Set Point Scaling Gain [COND:D GAIN 4] and Remote
Set Point Scaling Bias [COND:D BIAS 4] parameters are used to
scale the output from the Performance controller to allow the Speed
controller to use it as the remote serial set point:
Serial SP = GAIN 4 * (Perf Output + BIAS 4)
Normally, GAIN4 is set to 1 and BIAS4 is set to zero. However,
when the companion Performance controller is using its Split Range
Output feature, this gain and bias will need to be appropriately con-
figured. (Note: This scaling is not applied when using a Dual-Loop
A/P controller, in which split range is not possible.)

Analog Remote Assigning the Analog Remote Set Point [COND:S SP 2] a value
Set Point between one and eight identifies the corresponding analog input as
a remote set point source. That input could then be connected to a
power source via a potentiometer to provide an external set point
dial, or to a DCS or other controller (which could determine whether
the Speed Controller was using that signal by monitoring any control
relay assigned the SPtk function).
The designated input is used as the remote set point only if the com-
puter remote set point is disabled and either the serial remote set
point source is disabled or an anSSP discrete input is asserted. The
remote set point will then vary from minimum to maximum governor
as the designated input’s signal variable rises from zero to 100.0
percent, unless the serial remote set point is disabled and Remote
Set Point Reverse [MODE:D fE 3] is On.

Cascade Set Point The cascade speed set point will vary from minimum to maximum
governor as the performance control response varies from zero to
100 percent, although its range can be further restricted by clamping
that response (see Cascade Control on page 90).

Speed Deviation A “Speed Dev” alarm is indicated whenever the Deviation Alarm
Alarm Threshold and Deviation Alarm Delay [COND:S ALARM 2] are both
exceeded. For example, if the threshold is 500 rpm, the delay is 2.0
seconds, and the set point is 8,000 rpm, an alarm will be indicated if

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 Series 3++ Speed Controller 89

the speed exceeds 8,500 rpm for at least two seconds. Setting the
delay and/or the threshold to zero disables this alarm.
This deviation is calculated from the actual set point, which can dif-
fer from its displayed value if it is being ramped from one value to
another. In addition, the speed deviation alarm for a generator that
is under Droop Control (see page 95) is based on the deviation from
the Rated Speed.

SV1

First-Order- Dead
Lag Filter Zone
Performance
Control Variable error
Performance Performance
– PID
Set Point

Direction Load Limits

Cascade Set Point

Figure 5-2 Functional Diagram of Cascade Loop

Cascade / The Speed Controller provides a second PID loop that can be used
either to regulate the throughput of the equipment your turbine is
Limiting Loop driving (that is, as an internal cascade control loop) or to limit the
minimum or maximum value of any single-input process variable.
If this Cascade / Limiting Loop [MODE:S fC 1] is enabled, its func-
tion is selected by the Limiting Control [MODE:S MVAR] parameter:
MVAR Off: selects Cascade Control (see page 90).
MVAR High: selects high Limiting Control (see page 91).
MVAR Low: selects low limiting control.
Either application calculates a PID response to the deviation of the
Performance Control Variable (PCV) from its set point or limit:
• The PCV Proportional Band [PID:C PB 1], PCV Reset Rate
[PID:C Kr 1], and PCV Derivative Coefficient [PID:C Td 1] tune
this loop’s control response.
• The PCV Direction of Action [MODE:C REV 1] specifies
whether that response increases or decreases as the PCV rises
above its set point or limiting control threshold.
• The PCV Minimum Set Point [COND:C SP LOW] and PCV Max-
imum Set Point [COND:C SP HIGH] specify its set point range.

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Performance Cascade or limiting control can only be applied to SV1 (that is, the
Control Variable CH1 analog input). In order to reduce the effects of analog signal
noise, this variable is passed through a first-order-lag software filter
governed by the PCV Filter Time Constant [PID:C Tf 1]. The front-
panel readouts display it and its set point/control threshold using the
scaling parameters for the CH1 measured variable (see page 57).

Cascade Control When the Cascade / Limiting Loop [MODE:S fC 1] is enabled but
Limiting Control [MODE:S MVAR] is not, that loop calculates a Cas-
cade Set Point (see page 88) for the rotational speed or generated
power from the deviation of the performance control variable from its
set point. This can be used to regulate the throughput of the driven
equipment (such as a pump, as shown in Figure 1-1).
This application’s dead zone is defined by the PCV Dead-Zone Bias
[PID:C r 1]. The PCV Direction of Action [MODE:C REV 1] specifies
whether PCV rises or falls with the turbine speed and power output:
• Select direct action [REV 1 Off] if speeding the turbine up would
raise PCV. The deviation is then calculated by subtracting the
performance control variable (PCV) from the performance set
point (PSP) and applying the dead-zone bias (r1):

 PSP – PCV – r1 PSP  PCV


e =  0 if PSP – PCV  r1

 PSP – PCV + r1 PSP  PCV

• Select reverse action (REV 1 On) if slowing the turbine down

would raise PCV. The deviation is then calculated by subtracting
the set point from the control variable and applying the dead-
zone bias:

 PCV – PSP – r1 PCV  PSP


e =  0 if PCV – PSP  r1

 PCV – PSP + r1 PCV  PSP

This loop’s output clamps (that is, the limits for the cascade speed or
power set point) are calculated from the Minimum Governor
[COND:S SP LOW], Maximum Governor [COND:S SP HIGH],
Minimum Load [SPEC:S b 1], and Maximum Load [SPEC:S b 3]:
SP min + b 1  SP span  SP c  SP min + b 3  SP span
SP span = SP max – SP min

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Performance Set The performance set point is the desired value (in percent) of the
Point cascade loop’s performance control variable, which can be varied
from the front panel or via computer communication (see Speed and
Set Point on page 26). Its minimum and maximum values are speci-
fied by the PCV Minimum Set Point [COND:C SP LOW] and PCV
Maximum Set Point [COND:C SP HIGH] parameters.
Enabling PCV Set Point Recall [MODE:C fC 3] configures the cas-
cade loop to retain its last operator-selected set point even when the
cascade set point is not being used. If you then toggle from manual
to automatic or select the cascade set point, bumpless transfers are
achieved by ramping this set point from the current value of PCV
back to its retained value at a rate set by the PCV Set Point Ramp
Rate [PID:C G].
If PCV Set Point Recall is disabled [MODE:C fC 3 Off], the cascade
loop’s set point will track PCV when the cascade set point is not
being used. If you then toggle from manual to automatic or select
the cascade set point, the control response will not change because
PCV and its set point will be equal.

Limiting Control When the Cascade / Limiting Loop [MODE:S fC 1] is enabled and
high or low Limiting Control [MODE:S MVAR] is selected, that loop
calculates a limiting control response when the performance control
variable (PCV) is beyond its limiting control threshold and the speed
is in its normal operating range:
MVAR High: configures it to limit the maximum PCV
MVAR Low: configures it to limit the minimum PCV
It can thus be used to limit the minimum or maximum value of any
single-input process variable (such as the steam inlet pressure).
As long as the performance control variable (PCV) is below its spec-
ified high limit (or above its specified low limit), the steam demand is
calculated from the speed control response. If PCV rises above (or
falls below) its limiting control threshold, PID responses are calcu-
lated for both the turbine speed and PCV, and the response that
would most quickly restore an acceptable PCV value is selected.
This limiting control response will be clamped if it reaches either the
Minimum Demand Clamp [COND:S OUT 1 LOW] or Maximum
Demand Clamp [COND:S OUT 1 HIGH].
Direct action [MODE:C REV 1 Off] should be selected if opening the
steam control valve would cause PCV to increase. Reverse action
[REV 1 On] is appropriate if closing that valve would raise PCV.
For example, assume you want to limit the minimum inlet steam
pressure. You would then set MVAR to Low (to limit the minimum
pressure) and REV 1 to On (because closing the control valve would
slow the turbine, thus raising the inlet pressure).

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Limiting Control The limiting control threshold is the value (in percent) above or
Threshold below which the limiting control loop calculates a non-zero limiting
control response. Within the range set by the PCV Minimum Set
Point [COND:C SP LOW] and PCV Maximum Set Point [COND:C
SP HIGH] parameters, it can be varied from the front panel or via
computer communication (see Limiting Control on page 30).
When setting the limiting control threshold, keep in mind that limiting
control is not initiated until PCV reaches that limit. Thus, a high limit
should be set somewhat below PCV’s maximum acceptable value,
while a low limit should be set somewhat higher than its minimum
acceptable value.
When limiting control is enabled, PCV Set Point Recall [MODE:C
fC 3] need not be set because the limiting threshold always retains
its operator-set value.

Control During each scan, the Speed Controller calculates proportional,

integral, and derivative responses to the deviation of the rotational
Response speed from its selected set point.
If limiting control is disabled, the performance control variable is
within the limiting control threshold, or the speed is outside of its nor-
mal operating range, the overall control response is calculated by
adding these speed control responses to the previously accumu-
lated integral response:
–
CR = CR P,N + CR I + CR I,N + CR D,N
where:
CRD,N = speed loop derivative response
CRi– = accumulated integral from previous scan
CRI,N = speed loop integral response
CRP,N = speed loop proportional response
If limiting control is enabled, the performance control variable is
beyond the limiting control threshold, and the speed is in its normal
operating range, limiting proportional, integral, and derivative
responses are also calculated. The controller will then select the
responses that will most quickly restore the limiting variable to an
acceptable value:
–
CR = CR P + CR I + CR I + CR D
where:
CRD,S = selected derivative response
CRI,S = selected integral response
CRP,S = selected proportional response

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UM3307 Series 3++ Speed Controller

Chapter 6 Generator Control

This chapter describes the operation and configuration of a Speed
Controller for a turbine-driven synchronous electric generator.

Basic The Speed Controller is adapted to a generator application (see

Figure 1-3) by enabling Generator Control [MODE:S fC 5]. Its Mode
Operation Selection features will then automatically select either isochronous
(frequency/speed) or droop (power) control. The droop algorithm is
configured to measure or estimate the generated power by enabling
or disabling MW Droop Control [MODE:S fC 6] control. If Cascade
Control (see page 90) is enabled, that loop’s control response is
used as a cascade power set point for the droop control loop.
If Limiting Control (see page 91) is enabled and the performance
control variable (PCV) is beyond its limit, the controller will use that
loop to calculate its control response until an acceptable PCV value
is restored, at which point droop or isochronous control is resumed.

Mode Selection A Speed Controller configured for generator control automatically

selects its control mode (isochronous or droop) based on its operat-
ing state, and the states of any discrete inputs assigned the
Generator Breaker (Gen), Utility Breaker (Util), and Isochronous
(Isoch) functions:
• Droop control is possible only while the Speed Controller is in
the Run State.
• If the Gen and Util inputs are both asserted, the controller will
operate in its Droop Control mode and the operating state will
display as “Droop”.
• If the Gen input is set but the Util input is cleared, Isochronous
Control (“Isoch”) is selected only if an Isoch input is asserted,
otherwise droop control (“Droop”) is applied.
• If the Gen input is cleared, the operating state indicates the
speed is being controlled and the mode that would be selected
if that breaker were closed (“Spd/Isoch” or “Spd/Droop”).
The front-panel GenPwr LED will be lit whenever generator control
is enabled and the Gen input is asserted. As shown in Figure 1-3,
that input is usually connected to the breaker connecting the gener-
ator to the local bus, so the controller will automatically control the
speed if that breaker is open (that is, no power is being developed).
Similarly, the Util input is usually connected to the utility breaker, so
the controller will operate in the selected droop control mode if the
generator is delivering power to the utility grid.

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94 Chapter 6: Generator Control

A Gen input must be assigned and asserted before the controller will
operate in its droop control mode. If no Util inputs are defined, the
controller will assume the generator is never connected to the utility
grid. If no Isoch inputs are defined, the controller will always select
droop control when the Gen input is asserted.

Isochronous During start-ups and when the generator is off-line, the control
response must be varied as needed to accelerate the turbine to
Control or maintain the desired speed. This is achieved by operating as
described in Chapter 5 when the Gen input is cleared.
Speed control is also applied when the Gen and Isoch inputs are
asserted but the Util input is cleared. Because this also regulates
the frequency of the presumably isolated generator, it is referred to
as isochronous control. This is appropriate for on-line generators
that are not connected to others via a common bus, or for any one
generator on such a common bus (provided it is large enough to
control the bus frequency).
When this mode is selected, the general PID algorithm calculates
the control response based on the deviation of the speed from its
local set point, using the Speed Proportional Band [PID:S PB 1],
Speed Derivative Coefficient [PID:S Td 1], and Speed Reset Rate
[PID:S Kr 1]. The width of the dead zone is defined by the Speed
Dead-Zone Bias [PID:S r 1].
The PID coefficients can be further defined as functions of either the
turbine speed or intended valve position, as specified by the Char-
acterizer Argument [MODE:S SS 1]:
SS 1 On: PB = PB1 · f1 (IVP), Kr = Kr1 · f2 (IVP), r = r1 · f3 (IVP)
SS 1 Off: PB = PB1 · f1 (N), Kr = Kr1 · f2 (N),r = r1 · f3 (N)
where:
f1() = Proportional Band Characterizer [COND:S f(X) 1 #]
f2() = Reset Rate Characterizer [COND:S f(X) 2 #]
f3() = Dead-Zone Characterizer [COND:S f(X) 3 #]
Each of these characterizing functions is entered as ten numbers
that define its value at equally spaced percentages of the selected
argument (0, 11.1, …, 88.8, 100.0). Intermediate values of the char-
acterized coefficients are then calculated by linear interpolation.

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 Series 3++ Speed Controller 95

Because the speed is nearly constant in generator applications, the

control response (intended valve position) is usually selected as the
Characterizer Argument.

When setting the coefficients for this loop, keep in mind that the
speed and its set point are normalized relative to the Maximum Con-
Note: trol Speed, and the PID coefficients are characterized with respect
to the intended valve position or turbine speed.

When switching from droop to isochronous control, the local set

point is automatically selected and initialized to the Rated Speed
[COND:S LVL 4].

Set Point
RPM

Speed

P-Plus-PID
Output

Proportional

Time
Figure 6-1 Proportional-Plus-PID Control Response

Droop Control A traditional droop control response is proportional to the difference

between the speed and its set point. The Speed Controller provides
much smoother operation by using a PID response to the deviation
between the speed/droop set point and the sum of the speed and a
function of the generated power:
SP S = N 0   1 + K  SP J  = N 0 + K  N 0  SP J
e = SP S – N – K  N 0  J
=  N 0 – N  + K  N 0   SP J – J 
where
J= normalized generated power
K= Droop Control Gain [SPEC:S K]
N= actual speed
N0 = Rated Speed [COND:S LVL 4]
SPJ = normalized power set point

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96 Chapter 6: Generator Control

SPS = speed/droop set point

For example, if the droop gain is 4.0 percent and the rated speed is
3600 rpm, the droop set point would range from 3600 to 3744 rpm
as the power set point ranged from zero to 100 percent. The PID
loop would increase the steam flow if too little power was generated
or the speed fell below 3600 rpm.
Within the controller, the error and speeds are normalized with
respect to the Maximum Control Speed [COND:S DISPLAY HIGH].
The generated power can either be measured (Megawatt Droop) or
a characterized function of the control valve position (Valve Droop).
In either case, the generated power and power set point are normal-
ized with respect to a configured maximum.
The displayed power and power set point (see Droop Operation on
page 33) are scaled using the parameters [COND:D DISPLAY 3
HIGH, LOW, and •] for the CH3 measured variable (see page 57),
no matter which droop control mode is selected.
The PID coefficients for this loop are set by the Droop Proportional
Band [PID:S PB –], Droop Reset Rate [PID:S Kr –], Droop Deriva-
tive Coefficient [PID:S Td –], and Speed Dead-Zone Bias [PID:S
r 1]. The proportional band and reset rate can be further defined as
functions of either the turbine speed (N) or intended valve position
(IVP), as specified by the Characterizer Argument [MODE:S SS 1]:
SS 1 On: PB = PB1 · f1 (IVP), Kr = Kr1 · f2 (IVP), r = r1 · f3 (IVP)
SS 1 Off: PB = PB1 · f1 (N), Kr = Kr1 · f2 (N),r = r1 · f3 (N)

When tuning this loop, keep in mind that the speed and speed/droop
set point are normalized relative to the Maximum Control Speed,
Note: and the PID coefficients are characterized with respect to the
intended valve position or turbine speed.

Droop Dead Zone The speed of the synchronous generators connected to a public
power grid or other common bus will increase if the load falls or
decrease if the load rises, thus causing the grid frequency to vary.
Such variations are countered primarily by one unit operating under
isochronous (speed) control. However, because the droop control
algorithm reacts to both speed and power deviations (see previous
page), all other units will assist by automatically delivering more
power when the frequency drops and less when it rises.

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 Series 3++ Speed Controller 97

For small generators, the steam flow fluctuations resulting from

minor speed/frequency variations can be more trouble than they are
worth. Setting a non-zero Speed Dead-Zone Bias [PID:S r 1] will
cause the droop algorithm to ignore minor speed and power fluctua-
tions. Alternately, it can be configured to ignore only minor speed
fluctuations by specifying a non-zero Sync Speed Dead-Zone Bias
[PID:S r –], which is the minimum speed deviation the droop algo-
rithm will respond to:

e + r e  –r

e =  0 for –r  e  r

e – r er

This creates a dead zone around the synchronous speed, the width
of which is twice the value of r –.

Although assigning the r – parameter a large enough value would

Note: configure the droop loop to ignore any speed variation, the controller
would still shut the unit down if all speed inputs failed.

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98 Chapter 6: Generator Control

Power Set Point When droop control is active, the power set point is calculated from
the speed/droop set point. Any enabled source can be selected (see
Speed and Set Point on page 26 and Speed Set Point on page 87):
• The local set point cannot be disabled. When it is selected, the
Raise and Lower keys and SpdUp and SpdDn discrete inputs
manipulate the speed/droop set point. If the Computer Remote
Set Point [MODE:D LOCK 8] is disabled, that set point can also
be specified via the Modbus and OPC power set point variables.
• If a remote set point is configured, it conveys the desired power
(not the speed/droop set point) and is clamped to the specified
minimum and maximum load:
• If the Computer Remote Set Point is enabled, it is controlled
by the Power SP holding register and Power_SPW variable.
• If an Analog Remote Set Point [COND:S SP 2] is configured,
the span of that signal represents zero to maximum power.
• If a Serial Remote Set Point [MODE:S fC 4] was specified, the
control response of the companion controller specifies zero
to maximum power. Its speed tracking feature would have to
scale the reported set point from a percentage of maximum
control speed to a percentage of the droop set point range.
• If the cascade set point is enabled and selected, the power set
point is varied by the Performance Control Variable (see page
90) control loop. If it is configured to regulate the inlet steam
pressure, the generated power will be automatically adjusted as
more or less steam is generated.

Load Limits The upper and lower limits for the power and speed/droop set points
(and the cascade loop’s PID response) are defined by the Maximum
Load [SPEC:S b 3] and Minimum Load [SPEC:S b 1] parameters:
b 1  SP J  b 3
N 0 + K  N 0  b 1  SP S  N 0 + K  N 0  b 3
Control relays assigned the Limt function will activate and a “Max
Load” alarm will be indicated if the generated power (measured or
characterized) reaches its Maximum Load limit. Although no such
indications occur if it reaches the Minimum Load limit, the limiting
control loop cannot drive the generated power below that limit.
You can also enable a Remote Maximum Load Limit [MODE:S
fC 7], in which case the maximum power set point is controlled by
signal variable SV6. If that signal is less than the Minimum Load, it
will override that limit and thus force the load set point to equal SV6:
lesser of (b1 and SV6)  SPJ  SV6
If the remote maximum load signal fails, the controller will fall back
to using the constant limit set by the Maximum Load.

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 Series 3++ Speed Controller 99

MW Droop
SPJ SPS JD
· K · N0 + N0 PID

J
· K · N0

N
Valve Droop
SPJ SPS JD
· K · N0 + N0 PID

J
· K · N0 f4()

Figure 6-2 Megawatt and Valve Droop Control

Megawatt Droop When MW Droop Control [MODE:S fC 6] is enabled, the Speed

Controller implements droop control using signal variable SV3 as a
power measurement. In order to reduce the effects of analog signal
noise, this variable is passed through a first-order-lag software filter
governed by the PCV Filter Time Constant [PID:C Tf 1].
In order to scale this loop’s control variable relative to the capacity of
the generator (rather than that of the transmitter), it is calculated by
dividing the selected MW input (SV3) by the Maximum MW Signal
[COND:D LVL 7]:
J = SV  MW max
where all values are in percent. For example, if an 80 MW generator
is equipped with a 100 MW transmitter, LVL 7 should be set to 80
percent. This loop’s control variable would then rise from zero to 100
percent as the generated power rose from zero to 80 MW.
This loop will fall back to valve droop control and indicate a “MW
Fallbck” alarm if the CH3 input fails. If the local set point is selected
when this fallback occurs, it is back-calculated from the speed and
power demand to yield a zero error:
LSP = N + K  N 0  f 4(J D)

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100 Chapter 6: Generator Control

100

Generated Power (%)

f(X) 4 6

X46
0 Power Demand (%) 100
Figure 6-3 Defining Power as a Function of Valve Position

Valve Droop The Speed Controller is configured to apply valve droop control by
disabling MW Droop Control [MODE:S fC 6]. The generated power
is then estimated from the Power Demand (see page 103):
J = f 4(J D)
where
f4() = Generated Power Characterizer [COND:S f(X) 4 # and X 4 #]
JD = power demand (clamped droop control response)
J = estimated power output (in percent)
The f(X) 4 0 and f(X) 4 9 values, which specify the percentage of the
maximum possible power that would be generated when the control
response is zero and 100.0 percent (valve fully closed and open,
respectively), should be set to zero and 100.0 percent. As shown in
Figure 6-3, the other eight f(X) 4 and corresponding X 4 parameters
specify the percentage of the maximum power that would be gener-
ated at eight other valve positions. Each X parameter’s value must
exceed (and cannot equal) that of its predecessor.

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 Series 3++ Speed Controller 101

Breaker If the generator breaker is opened while the generator is on-line, the
resulting mismatch between its load and the turbine’s power output
Fallback can rapidly accelerate them beyond their maximum safe speeds. In
such situations, the Speed Controller will protect your equipment by
rapidly reducing or even cutting off the steam flow to the turbine:
• If the Breaker Shutdown Fallback [MODE:S fD 3 3] is enabled,
an emergency shutdown will be initiated if the Gen input is
cleared while the controller is in its Run operating state.
• If the Breaker Shutdown Fallback is disabled [fD 3 3 Off], the
controller will switch to isochronous control (if necessary),
reduce the speed control response to its Minimum Demand
Clamp [COND:S OUT 1 LOW], and set the local set point to the
Rated Speed [COND:S LVL 4] if the Breaker Rated Fallback
[MODE:S fD 3 4] is enabled, or to Minimum Governor [COND:S
SP LOW] if it is not [fD 3 4 Off].
If the breaker opens while the controller is in manual, it will revert to
automatic and execute the selected overspeed fallback.

These fallbacks supplement the previously-described Overspeed

Protection (see page 113) features. Like the load loss response,
Note: they anticipate and attempt to prevent excessive speeds. In con-
trast, electronic overspeed trip waits until the turbine reaches an
excessive speed before shutting it down.

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 Series 3++ Speed Controller 103

UM3307 Series 3++ Speed Controller

Chapter 7 Output Variables

This chapter tells how the intended valve position and actuator con-
trol signal are calculated from the speed control response.

Control Response

Demand Clamps

Power Demand
Extraction
Decoupling
Required Flow Rate

Manual Physical Clamps

or Position
Feedback
Intended Valve Position Input

OUT Readout Output Reverse Valve Position Test

Actuator Control Signal

Figure 7-1 Output Variables and Transformations

Intended Valve As shown in Figure 7-1, the intended steam flow and corresponding
control valve position are calculated by applying one or more of the
Position following transformations:
Power Demand • The Control Response (see page 92) represents the required
Required Flow Rate power output. When Manual Operation (see page 105) is active,
it tracks or is calculated from the intended valve position.
• For a single-stage turbine, the control response also represents
the required steam flow. The intended valve position (IVP) is
calculated by applying only the Demand Clamps.
• For a two-stage turbine, the Extraction Control Interface calcu-
lates the required inlet flow by decoupling the power demand
from a companion Extraction Controller’s extraction demand. It
then calculates the IVP by applying the V1 physical clamps.
• In either application, the Actuator Control Signal will usually
equal the IVP, but can be calculated as its compliment by the
output reverse algorithm.

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104 Chapter 7: Output Variables

Demand Clamps When the controller is operating in its Run state and the speed set
point is between Minimum Governor and Maximum Governor, the
Minimum Demand Clamp [COND:S OUT 1 LOW] and Maximum
Demand Clamp [COND:S OUT 1 HIGH] limit the control response.
During manual operation or when the set point is below Minimum
Governor (such as during a start-up or shut-down sequence), the
power demand can have any value from zero (0) to 100 percent.
During a start up, if the power demand is outside the clamped range
when the turbine reaches Minimum Governor, the clamps are not
applied until normal control actions move the valve into the clamped
range. However, once the valve enters that range, it is confined
there as long as the controller remains in the Run state.
For example, suppose the demand clamps are set at 15 percent and
90 percent. If the speed control response is 10 percent when the set
point reaches Minimum Governor, the clamps will not suddenly
increase the power demand to 15 percent. Instead, the controller
waits for it to rise above 15 percent as a result of normal control
action, then keeps it at or above that level.

Extraction Control The Series 3++ Speed Controller can be paired with a companion
Interface Extraction Controller to regulate both the rotational speed and low-
pressure header pressure or flow rate of a single automatic
extraction or induction turbine.
In such applications, the Speed Controller calculates the power
demand and directly manipulates the high-pressure control valve
(V1). The Extraction Controller calculates the steam flow required to
maintain the desired extraction pressure or flow rate and directly
manipulates the low-pressure control valve (V2). The required high
and low-pressure section flow rates (the intended valve positions)
are calculated as functions of both steam demands, as described in
the Loop Decoupling section in Chapter 5 of UM3308.
The Speed Controller is adapted to such applications by setting
its Extraction Controller ID [MODE:D fC 0] parameter equal to the
Controller ID Number of its companion Extraction Controller. You
must also set the V1 Minimum Clamp [COND:D OUT 0 LOW] and
V1 Maximum Clamp [COND:D OUT 0 HIGH], as described in the
Physical Clamps section in Chapter 5 of UM3308, and assign appro-
priate values to the Minimum Demand Clamp [COND:S OUT 1
LOW] and Maximum Demand Clamp [COND:S OUT 1 HIGH].
In non-extraction applications, the Extraction Controller ID must be
set to Off to disable the demand decoupling and physical clamps.

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Manual Operation Manual control of the intended valve position can be initiated at any
time (see Manual Operation on page 44), provided Manual Opera-
tion [MODE:S MOR 2] has been enabled and the controller is not
operating in its Tracking or Shutdown state.

Manual Override Unless Manual Override [MODE:S MOR 1] is enabled, automatic

control will resume if the Maximum Governor speed is exceeded
while operating in manual. The operator can then help the controller
restore an acceptable speed by pressing the Lower key to close the
valve at a faster rate, but cannot press the Raise key to retard valve
closure.
If you enable Manual Override [MOR 1 On], the valve will remain in
its manually selected position even if subsequent load variations
cause the speed to increase above Maximum Governor. You can
also continue opening the valve even if the speed is above that limit.

We advise against enabling this override because it leaves the

Warning! overspeed trips as the only means of preventing even small
load variations from causing an over-accelerating the turbine.

Remote Manual Remote control of the intended valve position can be configured by:
• assigning a discrete input the ReMan function, and
• connecting the signal the IVP should track to analog input CH2.
The IVP will then track the CH2 signal variable when the ReMan
input is asserted. Automatic operation will resume when that dis-
crete input is cleared or if that analog input fails.

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106 Chapter 7: Output Variables

Actuator The actuator control signal (Act) is the intended value (in percent of
span) of the analog output used to position the control valve. It is
Control Signal calculated by applying the Output Reverse to the IVP.

Output Reverse If increasing the actuator control signal closes the control valve, that
signal must decrease as the intended valve position rises.
It can be configured to do so by enabling Output Reverse [MODE:S
REV 1]. The actuator control signal (Act) is then calculated by com-
plementing the intended valve position (IVP):
ACT = 100% – IVP
An increase in the intended position will then cause a decrease in
the control signal, thus driving the valve further open. If Output
Reverse is disabled [REV 1 Off], the control signal will be the same
as the intended valve position.
For example, assume the intended valve position is 80 percent
open. If REV 1 is On, the actuator control signal will be 20 percent
(100 – 80). For a 4 to 20 mA circuit, this would be a 7.2 mA signal. If
REV 1 is Off, the control signal will be 80 percent, which would pro-
duce a 16.8 mA signal.

Valve Position This test can compare either a pressure or valve position measure-
ment to the actuator control signal to determine whether or not the
Test control valve is in the intended position. To set it up, set the First
Output Assigned Variable [COND:D OUT 1] to ActP and connect
one of the following position feedback signals to analog input CH4:
• a measurement of the actual position of the control valve or its
actuator, or
• a measurement of the control element’s current-to-hydraulic
(I/H) or current-to-pneumatic (I/P) converter pressure.
A valve position failure (see Output and Valve Position Failures on
page 50) will then be indicated if signal variable SV4 and the
intended actuator position (Act) differ by more than five percent
(5.0%) for a minimum time defined by the Output Failure Delay
[COND:D CONST 2].
Enabling this test also enables the Output Loopback Test. Although
both tests activate the same relays, the associated failures set dif-
ferent Modbus discretes and post different alarm messages.

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UM3307 Series 3++ Speed Controller

Chapter 8 States and Transitions

This chapter tells how to configure the automatic sequencing and
overspeed protection features.

Automatic Two basic sequences are used to ramp the speed up or down:

Sequences • The full Start-Up Sequence (see page 108) starts the turbine
and accelerates it to the Rated Speed. Parts of this sequence
can be used to start the turbine and accelerate it to an idle
speed or to ramp a running turbine to the Rated Speed.
• The full Stop Sequence (see page 110) slows a loaded turbine
to the Minimum Control Speed, then closes the control valve.
Portions of this sequence can be used to stop an idling turbine
or idle a loaded turbine. The final action in this sequence is an
emergency shutdown (ESD) that closes the valve as rapidly as
possible.
When any ramped sequence (startup, stop, rated, or idle) is initiated
(see Sequencing Operation on page 35), the local speed set point is
selected and ramped to an associated target speed (see Idle and
Rated Speeds on page 79), using Critical Speed Avoidance (see
page 111) techniques to avoid operating within the Critical Speed
Ranges (see page 79).
Initiating any sequence aborts any other already in progress (except
an emergency shutdown), as does switching to manual operation.
Provided the set point is above the Idle1 Speed, you can also abort
any ramping sequence via the front panel, discrete inputs, or com-
puter communication.

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108 Chapter 8: States and Transitions

Maximum Governor

Failsafe
Timer
remote or cascade set

Speed Set Point

Actuator Position

Remote or Cascade Set Point point ramped from Rated

Rated local SP
Minimum Governor stays at Rated

Idle 2 sequence ends

Idle 2

ramp rate changes above highest Idle speed

Critical
set point jumps critical range
Range 2
actuator travel
cannot exceed
LVL 0 Critical
set point jumps critical range Range 1
LVL 0

actuator moved Idle 1 sequence ends

to LVL – Idle 1

LVL –
Minimum
Control
startup aborts without
valid speed input
below Min. Control, above Minimum Control, Time
valve is ramped open set point is ramped

Figure 8-1 Start-Up, Load, and Rated Sequences

Start-Up The start-up sequence (Figure 8-1) initially ramps the governor
Sequence valve open, then switches to PID control and ramps the local set
point up to the selected target speed:
Step 1: The intended valve position (IVP) is raised at the Actuator
Ramp Rate [PID:S G 2], thus ramping open the control valve. If
this ramp reaches the Start-Up Valve Limit [COND:S LVL 0], the
IVP is held there until the Minimum Control Speed [COND:S
DISPLAY LOW] is reached or the Failsafe Timer is triggered.
Step 2: Local set point speed control is initiated when the turbine
reaches the Minimum Control Speed. That control response is
reduced to the Initial PID Output [COND:S LVL –], after which
the set point is raised from the Minimum Control Speed at the
Initial Startup Ramp Rate [COND:S LVL 6 LOW].

The controller ramps the local speed set point at the Initial Startup
Ramp Rate until it reaches the highest configured Idle target, after
Note: which it ramps the set point at the Final Startup Ramp Rate
[COND:S LVL 6 HIGH].

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Step 3: If the sequence was initiated by selecting the Idle1 operating

mode, it terminates when the turbine reaches its Idle1 Speed
[COND:S LVL 3 1]. Otherwise, the local set point continues to
ramp up.
Step 4: If the sequence was initiated by selecting the Idle2 mode, it
terminates when the turbine reaches its Idle2 Speed [COND:S
LVL 3 2]. Otherwise, the local set point continues to ramp up.
Step 5: If the sequence was initiated by selecting the Idle3 mode, it
terminates when the turbine reaches its Idle3 Speed [COND:S
LVL 3 3]. Otherwise, the local set point continues to ramp up.
Step 6: If the sequence was initiated by selecting the Rated mode, it
terminates when the Rated Speed [COND:S LVL 4] is reached.
The speed control loop then switches to the selected set point:
• If the local set point is selected, it remains at the Rated Speed
until changed by the operator.
• If the remote set point is selected, it is ramped at the General
Set Point Ramp Rate [PID:S G 1] from the Rated Speed to the
value received from the designated remote source.
• If the cascade set point is selected, it is ramped at the General
Set Point Ramp Rate from the Rated Speed to the value cal-
culated by the cascade control loop.

Permissive There are usually conditions (such as oil pressure and temperature
Conditions requirements) that should be met before starting the turbine. Some
of these can then be ignored, while others must continue to be met.
The Speed Controller monitors these conditions via its Permissive
and ESD Mode inputs, which are configured by setting the corre-
sponding Discrete Input Assigned Function [COND:D IN ##]:
• Permissive inputs assigned the +Start function must be set to
initiate a startup, while -Start inputs must be cleared. They are
ignored once the turbine is running.
• ESD Mode (and ESDae) inputs with the -ESD function must be
set to start or continue running the turbine, +ESD inputs must be
cleared.
During the design and installation of your control system, you should
create a list of each controller’s permissive inputs. It should identify
the physical condition (for example, low hydraulic pressure) corre-
sponding to each input and note whether its input must be asserted
or cleared before starting the turbine. If you have such a list, it can
be used in conjunction with the Input Signal Values [MODE TEST 4]
test to identify unsatisfied conditions. This will enable your operators
to identify these problems and determine how to solve them.

Failsafe Timer The Failsafe Timer [COND:S LVL 2] defines the maximum length of
time, in seconds, that the initial IVP ramp will continue without at

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110 Chapter 8: States and Transitions

least one valid speed signal. If no speed input reaches the Control
Threshold [COND:S ALARM 1] within this allotted time, the control-
ler will abort the startup and shut the turbine back down. Setting this
timer to zero disables it. A start-up sequence will then continue
indefinitely even if no valid speed signal is ever received.

Maximum Governor
Shut-Down
Delay
Speed Set Point

Minimum Governor

Idle 3 Idle3 sequence ends

Critical
Range 2 set point jumps critical speed range

Idle 2 Idle2 sequence ends

Critical
Range 1 set point jumps critical speed range

Idle 1 Idle1 sequence ends

Minimum
Control
set point and actuator
position drop to zero

Time
Figure 8-2 Stop and Unload Sequences

Stop Sequence The stop sequence (see Figure 8-2) gradually closes the steam con-
trol valve until the turbine slows to its Minimum Control Speed, then
shuts it down:
Step 1: If the speed is greater than Minimum Governor, the control-
ler waits for the Shut-Down Delay [COND:S LVL 1] to elapse. In
the meantime, the shutdown can be cancelled by selecting the
Rated mode. This delay is skipped if the speed is less than Min-
imum Governor, and can be disabled by setting it to zero.
Step 2: If the local set point is not selected, the speed control loop
switches to that set point and sets it to the current speed.
Step 3: The local set point is ramped down to the Minimum Control
Speed [COND:S DISPLAY LOW] at the Shutdown Ramp Rate
[COND:S LVL 7], jumping through any critical speed ranges it
crosses.

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 Series 3++ Speed Controller 111

Step 4: When the turbine reaches its Minimum Control Speed, an

emergency shutdown is executed, which sets both the local set
point and the intended valve position to zero. This action can
also be initiated by selecting the shutdown operating mode, and
is automatically triggered by various process conditions.

Displayed
Set Point
Critical Speed
Range 2

Critical Speed
Range 1
Actual
Set Point
Desired Ramping Incorrect Ramping
Figure 8-3 Ramping Through a Critical Speed Range

Critical Speed Any set point ramp (including operator adjustment of the local set
Avoidance point) that encounters either of the Critical Speed Ranges (see page
79) will ramp the set point through it as shown in Figure 8-3. If the
set point reaches either range limit, its displayed value immediately
changes to the other limit and then resumes ramping at its previous
rate. Meanwhile, its actual value is ramped at the Critical Speed
Ramp Rate [COND:S SP 6] until it equals the displayed value, after
which both are ramped at the same rate.

If SP 6 is less than a startup or shutdown rate (LVL 6 HIGH or LOW

or LVL 7) and a sequence using one of those ramps encountered a
Caution: critical speed, it would become a continuous ramp at the SP 6 rate.
Setting SP 6 to zero would cause the actual set point to remain con-
stant even though the displayed set point would continue to change.

A Critical Speed Ramp Rate value of zero will be changed to 500

the next time the controller resets (for example, when parameter val-
ues are downloaded from a computer running a configuration
program).

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112 Chapter 8: States and Transitions

Critical Speed If the speed remains in either critical speed range for longer than the
Stalling Critical Stall Time [COND:S CONST 2] while operating manually or
at the maximum intended valve position, the controller will revert to
automatic, select its Idle State (see page 36), reduce the local set
point to the lower limit of that critical speed range, and indicate a
“CRZ Stall” alarm:
• During any automatic sequence or if the set point is less than
Minimum Governor, the maximum IVP is always 100 percent.
• Otherwise, it is defined by the Demand Clamps (see page 104).

Coordinated Each Series 3++ Controller transmits a Run status bit over Port 1
Sequencing that indicates its currently selected operating state. A Speed Con-
troller sets that bit when its start-up sequence terminates with the
speed above minimum governor or when the speed is manually
increased to that threshold, and clears it when a shutdown or idle
sequence advances past its initial delay.
If the Speed Controller is specified as the Serial Speed Tracking
[MODE:P fE 5] and Run/Stop Companion [MODE:P fB –] of a Series
3++ Performance or Dual-Loop A/P Controller, the control signal of
that compressor controller will track the unit’s rotational speed
during turbine startups and shutdowns and initiate its own load and
idle sequences in response to a specified stop/idle signal:
• If its D2 input is specified but no signal is connected, the com-
pressor loading sequence will be automatically initiated at the
conclusion of a turbine startup but there will be no way to idle
the compressor before shutting down the turbine.
• If its D2 input is specified and connected to a switch or DCS,
that device will be able to load and idle the compressor. An
orderly shutdown could then be initiated by first idling the com-
pressor and then triggering the turbine controller’s shutdown
sequence.
• If an analog input is specified, the compressor will be automati-
cally loaded and idled as the corresponding signal rises above
and falls below the Run/Stop Threshold [COND:P LVL 2].

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Overspeed All steam turbines are equipped with overspeed trips that will shut
them down if they exceed their maximum safe rotational speeds.
Protection This protection can be supplemented (but not replaced) by the
Series 3++ Speed Controller’s electronic overspeed trip.
In addition, the controller’s load-shedding feature can be used to
rapidly reduce its power output in response to sudden load changes.
In many cases, this will prove an adequate response to conditions
that would otherwise trip the turbine.

Electronic Turbine-driven processes are subject to a variety of sudden

Overspeed Trip changes (for example, a sudden loss of load or coupling failure) that
can result in rapid acceleration to unsafe speeds. To protect against
such potentially hazardous situations, a turbine should always be
equipped with an overspeed trip device that would immediately and
unfailingly shut it down if it reached a maximum safe speed that is
known as the Mechanical Overspeed Trip speed (MOST).
An additional level of protection can be achieved by adding a sec-
ond trip system that shuts down the turbine at a slightly lower speed.
This system serves as the turbine’s first line of defense, while the
original system provides its primary, failsafe protection.
The Series 3++ Speed Controller’s electronic overspeed trip fills this
auxiliary role by shutting down the turbine before the primary trip
system kicks in.
Anytime the turbine speed exceeds the Electronic Overspeed Trip
[COND:S LVL 5] limit, the controller will immediately execute an
emergency shutdown. In addition to closing the steam valve by
reducing the intended valve position to zero, this sequence also trig-
gers any control relay that has been assigned the SD function. Such
relays are often used to close a trip and throttle valve.
The controller’s operating state will then display as “Overspd SD”
and the highest speed detected by the controller can be viewed via
the “MaxN” variable of the front-panel status screen’s Overspeed
Menu (see DS3307/O). That variable can be reset by the Maximum
Recorded Speed [COND:S SP 3] test sequence.

The Series 3++ Speed Controller’s Electronic Overspeed Trip

Warning! should not be used as a turbine’s only or primary overspeed
protection device.

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114 Chapter 8: States and Transitions

Maximum Speed cannot be recorded and set point cannot be raised above Maximum Control
Control To capture MOST, release ENTER key when
Mechanical mechanical trip shuts turbine down
Overspeed
Trip Releasing ENTER above
EOST initiates emergency
shutdown
Electronic
Overspeed
Trip
Releasing ENTER key between
Max. Governor and EOST ramps
set point down to Max. Governor Local Set Point
Ramp Rate
Speed

Pressing ENTER and D keys

allows set point to exceed
Maximum Governor

Maximum
Governor

Time
Figure 8-4 Typical Sequence of Overspeed Trip Test Events

Overspeed Trip The overspeed trip test (see Figure 8-4) is used to determine the
Test speed at which the turbine is shut down by its primary (mechanical)
overspeed trip device. If the Overspeed Trip Test [MODE:S fC 2]
parameter is enabled, any control relay assigned the Test function
will be set and you can execute this procedure either from the Oper-
ator Panel or via discrete inputs.
Before starting this test, you should use the Maximum Recorded
Speed [COND:S SP 3] sequence to reset the MaxN variable.
This test can be initiated by:
• setting any OStst discrete input; or
• selecting the front-panel status screen’s Overspeed Menu (see
DS3307/O), pressing the SCROLL button twice, then holding
down the ENTER key.
Either action will set any OSen outputs, change the displayed status
from “Overspeed Test” to “Overspeed TestActive”, and allow the
local set point to be raised above Maximum Governor:
• If the speed rises above Maximum Governor, the displayed
status will change to “AboveMaxGv”.
• If the speed rises above the Electronic Overspeed Trip threshold,
the displayed status will change to “Above EOST” and any OSen
outputs will toggle on and off.

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 Series 3++ Speed Controller 115

An Emergency Shutdown will be initiated if the ENTER key and

OStst input are released while the speed is above the EOST, or any
ESD discrete input is asserted. If the ENTER key and OStst input
are released with the speed below the EOST, the set point will ramp
down to Maximum Governor at the Local Set Point Ramp Rate.
Normally, you would continue raising the local set point until the pri-
mary overspeed protection device trips the turbine. If possible, that
device should also be used to assert an ESD discrete input. If that is
not possible, you should manually terminate the test by releasing
the ENTER key.
The Overspeed Menu’s “MOST” variable will then display the speed
at which the ENTER key was released or the ESD input asserted
and “MaxN” will display the turbine’s maximum speed. In addition,
if you have set up a discrete input that indicates when the trip and
throttle valve closes, the “TT Valv” variable will display the number
of milliseconds it took that valve to close after the emergency shut-
down was triggered.

Load Loss Asserting any fD31 discrete input causes the speed control loop to
Response immediately select its local set point and initialize it to the Default
Set Point [COND:S CONST 1]. This feature can be used to quickly
idle the turbine in response to a sudden loss of its own load or that
of its driven equipment.

Overspeed The overspeed prevention (OSP) function attempts to maintain the

Prevention steam turbine within an acceptable operating range by stepping the
steam valve closed by a given amount when the turbine speed (N)
reaches a specified threshold.
The OSP function will operate only when the turbine speed is above
the Maximum Governor speed. It is disabled while an Overspeed
Trip Test is active.
If the turbine speed exceeds the specified OSP threshold (Preven-
tion Speed [COND:S LVL HIGH]), the output of the Speed controller
is stepped down by the configured OSP control response (OSP Out-
put Step Size [COND:S CONST 3]), and an “OSP_Action” alarm is
posted. (A Prevention Speed setting of zero (0) disables the over-
speed prevention function.)
Once an OSP response is triggered, a configurable timer (OSP Min-
imum Step Time [COND:S CONST 4]) will begin to decrement. At
the conclusion of the timer, an additional OSP response will be trig-
gered if the turbine speed still exceeds the Prevention Speed.

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 Series 3++ Speed Controller 117

UM3307 Series 3++ Speed Controller

Appendix A Configuration Parameters

This appendix describes each Speed Controller configuration
parameter, including:
• its functional name and a description of that function,
• the range of values it can be given,
• the sequence of keys you must press to view or change it from the
Engineering Panel (often used as an alternate name),
• its confirming display prompt,
• any restrictions on the order in which it must be entered, and
• cross-references to the sections of this manual in which the asso-
ciated controller features are discussed.
Alternate Parameters The Speed Controller can store three alternate sets of parameter
values (in addition to the set it is using). Unlike compressor control-
lers, however, it does not support the recall of those parameters by
asserting discrete inputs.
Normalized and Most numeric parameters are stored and used in a normalized for-
Percentage Values mat, but are entered and displayed as the equivalent percentages.
Although this distinction is usually academic, failing to take it into
consideration can cause scaling problems.
If a parameter's defining equation calls for a normalized value but
this listing indicates it is a percentage (##.#), the value you give it
should be 100 times that calculated from the formula.
Viewing and Changing The engineering panel (Figure A-1) allows you to display or change
Parameter Values parameter values. To access this panel, loosen the screw at the bot-
tom of the front panel and swing the bezel out and to the left. This
allows simultaneous access to both the operator and configuration
interfaces.

To prevent process upsets, parameters should only be changed

Caution: with the controller in manual or off-line.

The parameter listings in this appendix include each parameter’s

engineering panel key sequence and confirming display. Pressing
the indicated keys will elicit the listed display, which consists of a
prompt followed by the current value:
• Enabling parameters can have the value Off and one or more oth-
ers such as On, High, Low, or single digits. These ranges are
indicated as “OFF/ON”, “OFF/HIGH/LOW”, or “Off/#”.
• List parameters have a limited number of possible values that are
generically indicated as “Value” or “Valu”.
• Numeric parameters can have any value within the listed range,
the precision of which is indicated by the number of “#” symbols

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118 Appendix A: Configuration Parameters

used to represent its digits. The position of any decimal point is

fixed. The space before a negative value is replaced by a “–”.
A hexadecimal ten leading digit shows as “A” (A0.0 is 100.0).
• For parameter arrays, the prompt also includes a digit correspond-
ing to the element index and represented by the character “#”.

ENGINEERING
PANEL
????????
PB – Kr 1 Td 2 Tf 3
fA fB SS MOR
Q CONST GAIN BIAS

G HIGH r 4 K 5 b 6
fC fD REV LOCK
M  ALARM DISPLAY

TL LOW RT 7 SO 8 C 9
fE MVAR TEST RA
IN LVL OUT SP
d • A 0
CLEAR AN IN COMM ENTER
f (X) X

SPEC
PID MODE COND
RESP

Figure A-1 Series 3++ Engineering Panel

You may examine the value of any configuration parameter while

the controller is on line without affecting the controller output or your
process, and without entering the configuration password.
Note:
If you attempt to change a parameter without enabling reconfigura-
tion, the No Store diagnostic message will be displayed and the new
value will be discarded.

After a parameter’s current value or status has been displayed, you

can terminate the procedure and clear the display by pressing the
gray CLEAR key. Or, if you have entered the Enable Reconfigura-

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 Series 3++ Speed Controller 119

tion [MODE LOCK 5 1] procedural key sequence, you can enter a

new value. The required procedure depends on the parameter type:
•Enabling parameters are changed by pressing the corresponding
key (0 for Off, 1 for On, HIGH, LOW, or a digit) followed by the
ENTER key. Until you do press ENTER, you can change your
mind and press as many of the allowed value keys as you need.
•List parameters are changed by pressing the decimal key until
the desired value is displayed and then pressing ENTER.
•Numeric parameters are changed by pressing the indicated num-
ber of numeric keys, including any leading or trailing zeroes,
then ENTER. Any decimal point is placed automatically. A nega-
tive value is defined by pressing the minus (–) key before the
first digit. A hexadecimal ten leading digit is defined by pressing
the HIGH key (100.0 is entered as HIGH 0 0). If you make a
mistake prior to pressing ENTER, you can press CLEAR to start
over.
For any parameter, pressing ENTER to finalize a value change also
clears the confirming display.

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120 Appendix A: Configuration Parameters

COND:C SP HIGH This parameter defines the maximum value that may be assigned to
the cascade/limiting control loop’s set point.
PCV Maximum Set
Point Range: PCV Minimum Set Point to 99.9 percent
Display: SPH ##.#
Reference: Cascade / Limiting Loop . . . . . . . . . . . . . . . . 89
Performance Set Point. . . . . . . . . . . . . . . . . . 91
Limiting Control Threshold . . . . . . . . . . . . . . . 92

COND:C SP LOW This parameter defines the minimum value that may be assigned to
the cascade/limiting control loop’s set point.
PCV Minimum Set
Point Range: 00.0 percent to PCV Maximum Set Point
Display: SPL ##.#
Reference: Cascade / Limiting Loop . . . . . . . . . . . . . . . . 89
Performance Set Point. . . . . . . . . . . . . . . . . . 91
Limiting Control Threshold . . . . . . . . . . . . . . . 92

COND:D BIAS 1 This parameter sets the bias used to scale and calibrate the high-
current output signal.
Output Scaling Bias
Range: .0000 to .9999
Display: B1 .####
Reference: High-Current Output. . . . . . . . . . . . . . . . . . . . 60

Note: This parameter can only be changed via the Engineering Panel.

COND:D BIAS 2 This parameter sets the bias used to scale and calibrate the high-
current output’s loopback input signal.
Loopback Scaling Bias
Range: –.9999 to .9999
Display: B2 .####
Reference: High-Current Output. . . . . . . . . . . . . . . . . . . . 60

Note: This parameter can only be changed via the Engineering Panel.

COND:D BIAS 4 This parameter sets the bias used to scale and calibrate a remote
serial set point.
Remote Set Point
Scaling Bias Range: –99.9 to 99.9
Display: BI4 ##.#
Reference: Serial Remote Set Point. . . . . . . . . . . . . . . . . 88

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 Series 3++ Speed Controller 121

COND:D CONST 2 This parameter defines the number of seconds the output loopback,
transducer feedback, or hydraulic feedback test deviation can be
Output Failure Delay
above its threshold before the corresponding alarm is signaled.
Range: 0.00 to 9.96 seconds (multiples of .04)
Display: CO2 #.##
Reference: Output Loopback Test . . . . . . . . . . . . . . . . . . 61
Valve Position Test . . . . . . . . . . . . . . . . . . . . 106

COND:D DISPLAY Each of these parameters determines whether or not the corre-
0# sponding measured variable can be viewed via the status screen’s
Analog In Menu (see DS3307/O).
Measured Variable
Display Range: Off variable cannot be displayed
On variable can be displayed
Display: D0# OFF/ON
Reference: Measured Variables . . . . . . . . . . . . . . . . . . . . 57

COND:D DISPLAY Each of these parameters defines the name and engineering units
0#– shown when the corresponding measured variable is viewed.
Measured Variable Range: name can be any eight and units can be any
Name and Units five symbols from Table 3-2
Display: AAAAAAAA, then EU:AAAAA
selected symbol (A) flashes
press • to select, then ENTER for each
Reference: Measured Variables . . . . . . . . . . . . . . . . . . . . 57

COND:D DISPLAY Each of these parameters defines the value the Analog In menu
0 # HIGH would display for the corresponding measured variable if the value
of its signal variable was 100.0 percent.
Measured Variable
Maximum Range: –9999 to 9999
Display: 0#H ####
Reference: Measured Variables . . . . . . . . . . . . . . . . . . . . 57

COND:D DISPLAY Each of these parameters defines the value the Analog In menu
0 # LOW would display for the corresponding measured variable if the value
of its signal variable was zero.
Measured Variable
Minimum Range: –9999 to 9999
Display: 0#L ####
Reference: Measured Variables . . . . . . . . . . . . . . . . . . . . 57

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COND:D DISPLAY Each of these parameters defines the position of the decimal point
0#• in the corresponding measured variable display.
Measured Variable Range: 0 #### (no decimal)
Decimal 1 ###. (trailing decimal)
2 ##.#
3 #.##
4 .### (leading decimal)
Display: 0#. 4321 (selected digit is replaced by •)
Reference: Measured Variables . . . . . . . . . . . . . . . . . . . . 57

COND:D GAIN 1 This parameter sets the gain used to scale and calibrate the high-
current output signal.
Output Scaling Gain
Range: .0000 to .9999
Display: G1 .####
Reference: High-Current Output. . . . . . . . . . . . . . . . . . . . 60

Note: This parameter can only be changed via the Engineering Panel.

COND:D GAIN 2 This parameter sets the gain used to scale and calibrate the high-
current output’s loopback input signal.
Loopback Scaling Gain
Range: 00.00 to 99.99
Display: G2 ##.##
Reference: High-Current Output. . . . . . . . . . . . . . . . . . . . 60

Note: This parameter can only be changed via the Engineering Panel.

COND:D GAIN 4 This parameter sets the gain used to scale and calibrate a remote
serial set point.
Remote Set Point
Scaling Gain Range: 0.0 to 9.99
Display: GA4 #.##
Reference: Serial Remote Set Point. . . . . . . . . . . . . . . . . 88

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 Series 3++ Speed Controller 123

COND:D IN ## Each of these parameters selects the function assigned to the corre-
sponding discrete input. If the value is positive, the input is asserted
Discrete Input Assigned
by raising its voltage above the neutral zone. If it is negative, the
Function
input is asserted by lowering that voltage below the neutral zone.
You can cycle through these parameters by pressing the COND and
IN keys, then pressing the decimal (•) key repeatedly.
Range: see Table 3-4
Display: ##+Value (press HIGH or LOW to select sign,
then press • to select function)
Reference: Discrete Inputs . . . . . . . . . . . . . . . . . . . . . . . . 64
Permissive Conditions . . . . . . . . . . . . . . . . . 109

COND:D LVL 7 This parameter defines the generator power input signal value that
corresponds to the maximum power output of the generator.
Maximum MW Signal
Range: 00.0 to 100.0 percent
Display: L7 ##.#
Reference: Megawatt Droop . . . . . . . . . . . . . . . . . . . . . . . 99

COND:D OUT 0 When Speed and Extraction Controllers are combined to regulate a
HIGH single extraction turbine, this parameter defines the maximum high-
pressure section flow, in percent of the fully-open flow through V1.
V1 Maximum Clamp
Range: 00.0 to 100.0 percent
Display: V1H ##.#
Reference: Extraction Control Interface . . . . . . . . . . . . . 104

COND:D OUT 0 When Speed and Extraction Controllers are combined to regulate a
LOW single extraction turbine, this parameter defines the minimum high-
pressure section flow, in percent of the fully-open flow through V1.
V1 Minimum Clamp
Range: 00.0 to 100.0 percent
Display: V1L ##.#
Reference: Extraction Control Interface . . . . . . . . . . . . . 104

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124 Appendix A: Configuration Parameters

COND:D OUT 1 This parameter selects the signal from which the high current output
First Output Assigned signal is calculated and enables or disables the current loopback,
hydraulic feedback, and transducer feedback tests.
Variable
Range: Act actuator control signal, no tests
ActL Act plus current Loopback test only
ActP ActL plus position feedback test
Off constant, minimum signal
None same as Off
Display: OT1 Valu
Reference: High-Current Output. . . . . . . . . . . . . . . . . . . . 60
Output Loopback Test . . . . . . . . . . . . . . . . . . 61
Valve Position Test . . . . . . . . . . . . . . . . . . . 106

COND:D OUT 1 – This parameter determines whether the high-current output is

generated as a unipolar or bipolar electrical signal.
Bipolar Output
Range: Off unipolar output
On bipolar output
Display: OT1- OFF/ON
Reference: Bipolar Output . . . . . . . . . . . . . . . . . . . . . . . . 60

COND:D OUT 2 This parameter identifies the internal variable from which the value
Second Output of the OUT2 analog output signal is calculated.
Assigned Variable Range: Act actuator control signal
Spd rotational speed
SP selected speed set point
RMSp remote set point
Off OUT2 = 4 mA
Display: OT2 Valu
Reference: Standard Analog Outputs. . . . . . . . . . . . . . . . 61

COND:D OUT 2 If OUT2 is a direct signal (Second Output Reverse [MODE:D REV 2]
HIGH Off), this parameter sets the value of the Second Output Assigned
Variable [COND:D OUT 2] at or above which that analog output will
Second Output Scale have its maximum value (100 percent). If OUT2 is a reversed signal
Maximum (REV 2 On), this parameter defines the value of that variable at or
above which that signal will have its minimum value (zero).
Range: 00000 to Maximum Control Speed
Display: 2H #####
Enter After: COND:S DISPLAY HIGH (if speed)
Reference: Standard Analog Outputs. . . . . . . . . . . . . . . . 61

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 Series 3++ Speed Controller 125

COND:D OUT 2 If OUT2 is a direct signal (Second Output Reverse [MODE:D REV 2]
LOW Off), this parameter sets the value of the Second Output Assigned
Variable [COND:D OUT 2] at or below which that analog output will
Second Output Scale have its minimum value (zero). If OUT2 is a reversed signal (REV 2
Minimum On), this parameter defines the value of that variable at or below
which that signal will have its maximum value (100 percent).
Range: 00000 to Maximum Control Speed
Display: 2L #####
Enter After: COND:S DISPLAY HIGH (if speed)
Reference: Standard Analog Outputs . . . . . . . . . . . . . . . . 61

Note: OUT 2 HIGH and LOW have no effect when OUT 2 is set to Act.

COND:D OUT 3 This parameter identifies the internal variable from which the value
of the OUT3 analog output signal is calculated.
Third Output Assigned
Variable Range: Act actuator control signal
Spd rotational speed
SP selected speed set point
RMSp remote set point
Off OUT3 = 4 mA
Display: OT3 Valu
Reference: Standard Analog Outputs . . . . . . . . . . . . . . . . 61

COND:D OUT 3 If OUT3 is a direct signal (Third Output Reverse [MODE:D REV 3]
HIGH Off), this parameter defines the value of the Third Output Assigned
Variable [COND:D OUT 3] at or above which that analog output will
Third Output Scale have its maximum value (100 percent). If OUT3 is a reversed signal
Maximum (REV 3 On), this parameter defines the value of that variable at or
above which that signal will have its minimum value (zero).
Range: 00000 to Maximum Control Speed
Display: 3H #####
Enter After: COND:S DISPLAY HIGH (if speed)
Reference: Standard Analog Outputs . . . . . . . . . . . . . . . . 61

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126 Appendix A: Configuration Parameters

COND:D OUT 3 If OUT3 is a direct signal (Third Output Reverse [MODE:D REV 3]
LOW Off), this parameter defines the value of the Third Output Assigned
Variable [COND:D OUT 3] at or below which that analog output will
Third Output Scale have its minimum value (zero). If OUT3 is a reversed signal (REV 3
Minimum On), this parameter defines the value of that variable at or below
which that signal will have its maximum value (100 percent).
Range: 00000 to Maximum Control Speed
Display: 3L #####
Enter After: COND:S DISPLAY HIGH (if speed)
Reference: Standard Analog Outputs. . . . . . . . . . . . . . . . 61

Note: OUT 3 HIGH and LOW have no effect when OUT 3 is set to Act.

COND:S ALARM 1 This parameter defines the minimum rotational speed below which
the signal from a magnetic pickup is considered unreliable.
Control Threshold
Range: 00000 to Maximum Control Speed
Display: A1 #####
Enter After: COND:S DISPLAY HIGH
Reference: Valid Speed Range . . . . . . . . . . . . . . . . . . . . 78
MPU Tests . . . . . . . . . . . . . . . . . . . . . . . . . . . 83
Failsafe Timer . . . . . . . . . . . . . . . . . . . . . . . 109

COND:S ALARM 2 These parameters define the “Speed Dev” alarm, which is indicated
if the difference between the speed and its set point exceed the
Deviation Alarm
Deviation Alarm Threshold for the minimum length of time set by the
Threshold
Deviation Alarm Delay. During droop control, the turbine speed is
Deviation Alarm Delay compared to the Rated Speed. This alarm can be disabled by set-
ting its threshold or delay to zero.
Range: 00000 to Maximum Control Speed
0.00 to 9.96 seconds (multiples of 0.04)
Display: A2 ##### (enter new limit, then)
A2 #.## (enter new delay)
Enter After: COND:S DISPLAY HIGH
Reference: Speed Deviation Alarm . . . . . . . . . . . . . . . . . 88

COND:S CONST 1 This parameter defines the initial value, the Load Loss Response
feature assigns to the local set point.
Default Set Point
Range: Minimum Governor to Maximum Governor (rpm)
Display: C1 #####
Enter After: COND:S DISPLAY HIGH
Reference: Load Loss Response . . . . . . . . . . . . . . . . . . 115

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 Series 3++ Speed Controller 127

COND:S CONST 2 This parameter defines the number of seconds that the speed can
remain in a critical speed range while the speed control response is
Critical Stall Time
at its maximum clamp or the controller is being manually operated.
After that many seconds, the speed is reduced to the lower limit of
that critical range, automatic operation is restored (if in manual), and
a “CRZ Stall” alarm is signaled.
Range: 000 to 999 seconds
Display: CO2 ###
Reference: Critical Speed Stalling . . . . . . . . . . . . . . . . . 112

COND:S CONST 3 This parameter defines the amount that the output of the Speed
controller will be stepped down when an Overspeed Prevention
OSP Output Step Size
action has been triggered to maintain the turbine speed at an
acceptable level.
Range: 00.0 to 99.9 percent
Display: CO3 #.##
Reference: Overspeed Prevention . . . . . . . . . . . . . . . . . 115

COND:S CONST 4 This parameter defines the minimum amount of time between Over-
OSP Minimum Step speed Prevention (OSP) responses. Once an OSP response has
Time been triggered, this amount of time must pass before another is
allowed. A value of zero is invalid, and is treated as the equivalent of
10 seconds.
This timer will begin to decrement when an OSP response steps
down the output of the Speed controller. At the conclusion of the
timer, an additional OSP response will be triggered if the turbine
speed still exceeds the Prevention Speed.
Range: 000 to 9.96 seconds
Display: CO4 #.##
Reference: Overspeed Prevention . . . . . . . . . . . . . . . . . 115

COND:S DISPLAY This parameter serves as a reference value for converting the abso-
HIGH lute speeds (in rpm) obtained from the speed inputs and displayed
on the front-panel readouts to the percent-of-range values the con-
Maximum Control troller uses internally. It should be set equal to or slightly greater
Speed than the maximum rotational speed your turbine could ever reach.
Range: 00000 to 64000 rpm
Display: HI #####
Reference: Valid Speed Range. . . . . . . . . . . . . . . . . . . . . 78
Idle and Rated Speeds . . . . . . . . . . . . . . . . . . 79
Scaling and Normalization . . . . . . . . . . . . . . . 82
Droop Control . . . . . . . . . . . . . . . . . . . . . . . . . 95

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128 Appendix A: Configuration Parameters

COND:S DISPLAY This parameter defines the minimum rotational speed below which
LOW the start-up and shut-down sequences ramp the actuator position
rather than the speed control loop’s set point.
Minimum Control
Speed Range: 00000 rpm to Maximum Control Speed
Display: LO #####
Enter After: COND:S DISPLAY HIGH
Reference: Control Range . . . . . . . . . . . . . . . . . . . . . . . . 78
Start-Up Sequence . . . . . . . . . . . . . . . . . . . 108
Stop Sequence . . . . . . . . . . . . . . . . . . . . . . 110

COND:S f(X) 1 # These parameters define the speed control loop’s proportional band
coefficient as a function of the Characterizer Argument [MODE:S
Proportional Band
SS 1].
Characterizer
You can cycle through these parameters by pressing the COND,
f(X), and 1 keys, then pressing the decimal (•) key repeatedly.
Range: 1.00 to 9.99
Display: Y1# #.##
Reference: Speed Control Loop . . . . . . . . . . . . . . . . . . . . 86
Isochronous Control . . . . . . . . . . . . . . . . . . . . 94

COND:S f(X) 2 # These parameters define the speed control loop’s integral action
coefficient as a function of the Characterizer Argument [MODE:S
Reset Rate
SS 1].
Characterizer
You can cycle through these parameters by pressing the COND,
f(X), and 2 keys, then pressing the decimal (•) key repeatedly.
Range: .000 to .999
Display: Y2# .###
Reference: Speed Control Loop . . . . . . . . . . . . . . . . . . . . 86
Isochronous Control . . . . . . . . . . . . . . . . . . . . 94

COND:S f(X) 3 # These parameters define the speed control loop’s dead-zone bias
as a function of the Characterizer Argument [MODE:S SS 1].
Dead-Zone
Characterizer You can cycle through these parameters by pressing the COND,
f(X), and 3 keys, then pressing the decimal (•) key repeatedly.
Range: .000 to .999
Display: Y3# .###
Reference: Speed Control Loop . . . . . . . . . . . . . . . . . . . . 86
Isochronous Control . . . . . . . . . . . . . . . . . . . . 94

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 Series 3++ Speed Controller 129

COND:S f(X) 4 # When valve droop control is selected, these parameters define the
and X 4 # generated power as a function of the control response (intended
steam control valve position).
Generated Power
Characterizer You can cycle through the X or f(X) parameters for this characterizer
by pressing the COND, X or f(X), and 4 keys, then pressing the dec-
imal (•) key repeatedly.
Range: 00.0 to 99.9 percent [X]
00.0 to 99.9 percent [f(X)]
Note: The value of each successive X value must
exceed (and cannot equal) that of its predecessor.
Display: X4# ##.# [X]
Y4# ##.# [f(X)]
Reference: Valve Droop . . . . . . . . . . . . . . . . . . . . . . . . . 100

COND:S LVL – This parameter defines the maximum initial valve opening for the
Initial PID Output start-up sequence’s closed-loop speed ramp. If the open-loop ramp
raises the intended valve position beyond this level, the steam flow
will be reduced as soon as any MPU indicates the Minimum Control
Speed [COND:S DISPLAY LOW] has been reached.
Range: 00.0 to 99.9 percent
Display: L- ##.#
Reference: Start-Up Sequence . . . . . . . . . . . . . . . . . . . . 108

COND:S LVL 0 This parameter defines the maximum valve opening for the start-up
Start-Up Valve Limit sequence’s open-loop ramp.
Range: 00.0 to 99.9 percent
Display: L0 ##.#
Reference: Start-Up Sequence . . . . . . . . . . . . . . . . . . . . 108

COND:S LVL 1 This parameter defines the length of time the controller will wait
before initiating a requested stop or idle sequence, thus giving the
Shut-Down Delay
operator time to rescind that request. This feature can be disabled
by setting its delay to zero.
Range: 000 to 999 seconds
Display: L1 ###
Reference: Stop Sequence . . . . . . . . . . . . . . . . . . . . . . . 110

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130 Appendix A: Configuration Parameters

COND:S LVL 2 During an automatic start up, this parameter defines the length of
time the controller will wait for the rotational speed to reach the Con-
Failsafe Timer
trol Threshold [COND:S ALARM 1] before its assumes the MPU
inputs have failed and shuts the turbine back down. This feature can
be disabled by setting its time limit to zero.
Range: 000 to 999 seconds
Display: L2 ###
Reference: Failsafe Timer . . . . . . . . . . . . . . . . . . . . . . . 109

COND:S LVL 3 1 This parameter defines the target speed for the Idle1 set point
ramps (setting it to zero disables all such sequences).
Idle1 Speed
Range: 00000 rpm to Idle2 Speed or Minimum Governor
Display: L3L#####
Enter After: COND:S DISPLAY HIGH
Reference: Idle and Rated Speeds . . . . . . . . . . . . . . . . . 79
Start-Up Sequence . . . . . . . . . . . . . . . . . . . 108

COND:S LVL 3 2 This parameter defines the target speed for the Idle2 set point
ramps (setting it to zero disables all such sequences). If the Idle1
Idle2 Speed
ramps are disabled, this target should also be set to zero.
Range: Idle1 Speed to Idle3 Speed or Minimum Governor
Display: L3H#####
Enter After: COND:S DISPLAY HIGH
Reference: Idle and Rated Speeds . . . . . . . . . . . . . . . . . 79
Start-Up Sequence . . . . . . . . . . . . . . . . . . . 108

COND:S LVL 3 3 This parameter defines the target speed for the Idle3 set point
ramps (setting it to zero disables all such sequences). If the Idle2
Idle3 Speed
ramps are disabled, this target should also be set to zero.
Range: Idle2 Speed to Minimum Governor
Display: L3H#####
Enter After: COND:S DISPLAY HIGH
Reference: Idle and Rated Speeds . . . . . . . . . . . . . . . . . 79
Start-Up Sequence . . . . . . . . . . . . . . . . . . . 109

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 Series 3++ Speed Controller 131

COND:S LVL 4 This parameter defines the target speed at which a full start-up or
rated sequence will terminate (for generator applications, this is nor-
Rated Speed
mally the synchronous speed).
Range: Minimum Governor to Maximum Governor
Display: L4 #####
Enter After: COND:S DISPLAY HIGH
Reference: Idle and Rated Speeds . . . . . . . . . . . . . . . . . . 79
Isochronous Control . . . . . . . . . . . . . . . . . . . . 94
Droop Control . . . . . . . . . . . . . . . . . . . . . . . . . 95
Breaker Fallback. . . . . . . . . . . . . . . . . . . . . . 101
Start-Up Sequence . . . . . . . . . . . . . . . . . . . . 109

COND:S LVL 5 This parameter defines the maximum speed that can be reached
before the electronic overspeed trip feature initiates an emergency
Electronic Overspeed
shutdown of the turbine.
Trip
Range: 00000 to Maximum Control Speed
Display: L5 #####
Enter After: COND:S DISPLAY HIGH
Reference: Control Range . . . . . . . . . . . . . . . . . . . . . . . . 78
Electronic Overspeed Trip . . . . . . . . . . . . . . 113

COND:S LVL 6 This parameter defines the rate at which the start-up sequences
HIGH increase the speed set point when it is above the highest configured
Idle speed.
Final Startup Ramp
Rate Range: 000 to 999 rpm/second
Display: L6H ###
Enter After: COND:S DISPLAY HIGH
Reference: Start-Up Sequence . . . . . . . . . . . . . . . . . . . . 109

COND:S LVL 6 This parameter defines the rate at which the start-up sequences
LOW increase the speed set point when it is below the highest configured
Idle speed.
Initial Startup Ramp
Rate Range: 000 to 999 rpm/second
Display: L6L ###
Enter After: COND:S DISPLAY HIGH
Reference: Start-Up Sequence . . . . . . . . . . . . . . . . . . . . 108

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132 Appendix A: Configuration Parameters

COND:S LVL 7 This parameter defines the rate at which the speed set point is
decreased by the shut-down sequence.
Shutdown Ramp Rate
Range: 000 to 999 rpm/second
Display: L7 ###
Enter After: COND:S DISPLAY HIGH
Reference: Stop Sequence . . . . . . . . . . . . . . . . . . . . . . 110

COND:S LVL 8 This parameter defines the upper limit of the controller’s first critical
HIGH speed range. Unless both it and the First Critical Speed Lower Limit
[COND:S LVL 8 LOW] are zero, the automatic start-up and shut-
First Critical Speed down speed set point ramps will jump through this range.
Upper Limit
Range: First Critical Speed Lower Limit to Second Critical
Speed Lower Limit or Minimum Governor (rpm)
Display: L8H#####
Enter After: COND:S DISPLAY HIGH
Reference: Critical Speed Ranges . . . . . . . . . . . . . . . . . . 79

COND:S LVL 8 This parameter defines the lower limit of the controller’s first critical
LOW speed range. Unless both it and the First Critical Speed Upper Limit
[COND:S LVL 8 HIGH] are zero, the automatic start-up and shut-
First Critical Speed down speed set point ramps will jump through this range.
Lower Limit
Range: 00000 rpm to First Critical Speed Upper Limit
Display: L8L#####
Enter After: COND:S DISPLAY HIGH
Reference: Critical Speed Ranges . . . . . . . . . . . . . . . . . . 79

COND:S LVL 9 This parameter defines the upper limit of the controller’s first critical
HIGH speed range. Unless both it and the Second Critical Speed Lower
Limit [COND:S LVL 9 LOW] are zero, the automatic start-up and
Second Critical Speed shut-down speed set point ramps will jump through this range.
Upper Limit
Range: Second Critical Speed Lower Limit to
Minimum Governor (rpm)
Display: L9H#####
Enter After: COND:S DISPLAY HIGH
Reference: Critical Speed Ranges . . . . . . . . . . . . . . . . . . 79

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 Series 3++ Speed Controller 133

COND:S LVL 9 This parameter sets the lower limit of the controller’s second critical
LOW speed range. Unless both it and the Second Critical Speed Upper
Limit [COND:S LVL 9 HIGH] are zero, the automatic start-up and
Second Critical Speed shut-down speed set point ramps will jump through this range.
Lower Limit
Range: First Critical Speed Upper Limit to
Second Critical Speed Upper Limit (rpm)
Display: L9L#####
Enter After: COND:S DISPLAY HIGH
Reference: Critical Speed Ranges . . . . . . . . . . . . . . . . . . 79

COND:S LVL HIGH This parameter defines the turbine speed threshold at which the
Overspeed Prevention function will step down the output of the
Prevention Speed
Speed controller to maintain the turbine speed at an acceptable
level. A setting of zero (0) disables the Overspeed Prevention
function.
Range: Maximum Governor to Maximum Control Speed
Display: LH #####
Enter After: COND:S DISPLAY HIGH
Reference: Overspeed Prevention . . . . . . . . . . . . . . . . . 115

COND:S OUT 1 This parameter defines the upper limit of the speed control response
HIGH (that is, the power demand).
Maximum Demand Range: Minimum Demand Clamp to 100.0 percent
Clamp Display: O1H ##.#
Reference: Limiting Control. . . . . . . . . . . . . . . . . . . . . . . . 91
Demand Clamps . . . . . . . . . . . . . . . . . . . . . . 104
Extraction Control Interface . . . . . . . . . . . . . 104

Note: A value of 100 percent disables the “HiActuator” alarm.

COND:S OUT 1 This parameter defines the speed control response’s lower limit.
LOW Range: 00.0 percent to Maximum Demand Clamp
Minimum Demand Display: O1L ##.#
Clamp Reference: Limiting Control. . . . . . . . . . . . . . . . . . . . . . . . 91
Breaker Fallback. . . . . . . . . . . . . . . . . . . . . . 101
Demand Clamps . . . . . . . . . . . . . . . . . . . . . . 104
Extraction Control Interface . . . . . . . . . . . . . 104

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134 Appendix A: Configuration Parameters

COND:S SP 1 This parameter defines the rate at which the local set point changes
when the front-panel Raise () or Lower () key is pressed for more
Local Set Point Ramp
than five seconds or a SpdUP or SpdDN discrete input is asserted.
Rate
Range: 000 to 999 rpm/second
Display: Accl ###
Enter After: COND:S DISPLAY HIGH
Reference: Local Set Point . . . . . . . . . . . . . . . . . . . . . . . . 87

COND:S SP 2 This parameter identifies the analog input signal, if any, that the
speed control loop uses as a remote set point.
Analog Remote Set
Point Range: Off no analog remote set point
1 to 8 analog input channel number
Display: RMSP OFF/#
Reference: Analog Remote Set Point. . . . . . . . . . . . . . . . 88
Power Set Point . . . . . . . . . . . . . . . . . . . . . . . 98

COND:S SP 4 These parameters configure the operation of any control relay

assigned the Swi1 function.
Switch 1 Mode
Switch 1 Speed Range: ±LATCH relay latches when speed rises above
(+) or falls below (–) specified threshold
±NLATC relay is tripped only if speed is above (+)
or below (–) specified threshold
Range: 00000 to Maximum Control Speed
Display: S1±Value (press HIGH or LOW to select sign,
• to select function, then ENTER to display speed)
S1±#####
Enter After: COND:S DISPLAY HIGH
Reference: Speed Switches . . . . . . . . . . . . . . . . . . . . . . . 80

COND:S SP 5 This parameter configures the operation of any control relay

assigned the Swi2 function.
Switch 2 Mode
Range: ±LATCH relay latches when speed rises above
Switch 2 Speed
(+) or falls below (–) specified threshold
±NLATC relay is tripped only if speed is above (+)
or below (–) specified threshold
Range: 00000 to Maximum Control Speed
Display: S2±Value (press HIGH or LOW to select sign,
• to select function, then ENTER to display speed)
S2±#####
Enter After: COND:S DISPLAY HIGH
Reference: Speed Switches . . . . . . . . . . . . . . . . . . . . . . . 80

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 Series 3++ Speed Controller 135

COND:S SP 6 This parameter sets the rate at which the local set point is ramped
through the critical speed ranges.
Critical Speed Ramp
Rate Range: 00000 to Maximum Control Speed rpm/second
Display: CR #####
Enter After: COND:S DISPLAY HIGH
Reference: Critical Speed Avoidance . . . . . . . . . . . . . . . 111

COND:S SP HIGH This parameter defines the maximum value that may be assigned to
the speed control loop’s set point.
Maximum Governor
Range: Minimum Governor to Maximum Control Speed
Display: SH #####
Enter After: COND:S DISPLAY HIGH
Reference: Normal Operating Range . . . . . . . . . . . . . . . . 78
Idle and Rated Speeds . . . . . . . . . . . . . . . . . . 79
Speed Set Point . . . . . . . . . . . . . . . . . . . . . . . 87
Cascade Control . . . . . . . . . . . . . . . . . . . . . . . 90

COND:S SP LOW This parameter defines the minimum value that may be assigned to
Minimum Governor the speed control loop’s set point.
Range: 00000 rpm to Maximum Governor
Display: SL #####
Enter After: COND:S DISPLAY HIGH
Reference: Normal Operating Range . . . . . . . . . . . . . . . . 78
Idle and Rated Speeds . . . . . . . . . . . . . . . . . . 79
Speed Set Point . . . . . . . . . . . . . . . . . . . . . . . 87
Cascade Control . . . . . . . . . . . . . . . . . . . . . . . 90
Breaker Fallback. . . . . . . . . . . . . . . . . . . . . . 101

MODE:C fC 3 This parameter determines how the cascade control loop’s set point
behaves when switching from manual to automatic operation. If the
PCV Set Point Recall
recall feature is enabled, that set point will ramp back to the last
value it had when manual operation was initiated. Otherwise, it will
be initialized to the value of the performance control variable at the
time automatic operation is restored.
Range: Off initializes to current PCV value
On ramps to previous automatic value
Display: fC3 OFF/ON
Reference: Performance Set Point . . . . . . . . . . . . . . . . . . 91
Limiting Control Threshold . . . . . . . . . . . . . . . 92

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136 Appendix A: Configuration Parameters

MODE:C REV 1 This parameter defines the direction of action for the cascade/limit-
ing control loop.
PCV Direction of Action
Range: Off response decreases if PV > SP
On response increases if PV > SP
Display: REV1 OFF/ON
Reference: Cascade / Limiting Loop . . . . . . . . . . . . . . . . 89
Cascade Control . . . . . . . . . . . . . . . . . . . . . . 90

MODE:D ANIN # Each of these parameters identifies the zero level of the correspond-
ing analog input signal (relative to its hardware configuration).
Offset Zero Input
Range: Off actual zero (for example, 0 to 5 Vdc)
On 20 percent offset zero (e.g., 4 to 20 mA)
Display: A# OFF/ON
Reference: Signal Variables . . . . . . . . . . . . . . . . . . . . . . . 57

MODE:D ANIN # Each of these parameters defines the maximum value for the corre-
HIGH sponding analog input’s analog-to-digital variable, above which that
input is considered to have failed.
Analog Input High
Alarm Limit Range: 00.0 to 102.2percent of 20 mA or 5.0 Vdc
102.3 21.0 mA (Namur NE 43)
102.4 no high alarm
Display: A#H ##.#
Reference: Transmitter Testing . . . . . . . . . . . . . . . . . . . . 56

MODE:D ANIN # Each of these parameters defines the minimum value for the corre-
LOW sponding analog input’s analog-to-digital variable, below which that
input is considered to have failed.
Analog Input Low
Alarm Limit Range: 00.0 to 102.4 percent
Display: A#L ##.#
Reference: Transmitter Testing . . . . . . . . . . . . . . . . . . . . 56

MODE:D COMM 0 This parameter identifies the controller in the network connected to
its serial Port 1. With the exception of redundant controllers, this ID
Controller ID Number
must be unique within that network.
Range: 1 to 8
Display: Ctrl# #
Reference: ID Numbers . . . . . . . . . . . . . . . . . . . . . . . . . . 75
Redundant Tracking. . . . . . . . . . . . . . . . . . . . 76

Note: This parameter can only be changed via the Engineering Panel.

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 Series 3++ Speed Controller 137

MODE:D COMM 0 • This parameter identifies the controller in the networks connected to
its serial Ports 2, 3, and 4. With the possible exception of redundant
Computer ID Number
controllers, this ID must be unique within each of those networks.
Range: 01 to 64
Display: Comp# ##
Reference: ID Numbers . . . . . . . . . . . . . . . . . . . . . . . . . . 75
Redundant Tracking . . . . . . . . . . . . . . . . . . . . 76

Note: This parameter can only be changed via the Engineering Panel.

MODE:D COMM 3 These parameters define the data transmission rate, parity setting,
and Modbus register scaling for the Port 3 communication channel.
Port 3 Baud Rate
Range: 4800, 9600, 19k2 (baud)
Port 3 Parity
Even, Odd, None (parity)
Port 3 Scaling 4000, 4095, 64k (100% value)
Display: PT3 Valu (press • to change, then ENTER)
PT3 Valu (press • to change, then ENTER)
PT3 Valu (press • to change, then ENTER)
Reference: Serial Communication Formats . . . . . . . . . . . 75
Modbus/OPC Configuration . . . . . . . . . . . . . . 75

MODE:D COMM 4 These parameters define the data transmission rate, parity setting,
Port 4 Baud Rate and Modbus register scaling for the Port 4 communication channel.
Range: 4800, 9600, 19k2 (baud)
Port 4 Parity
Even, Odd, None (parity)
Port 4 Scaling 4000, 4095, 64k (100% value)
Display: PT4 Valu (press • to change, then ENTER)
PT4 Valu (press • to change, then ENTER)
PT4 Valu (press • to change, then ENTER)
Reference: Serial Communication Formats . . . . . . . . . . . 75
Modbus/OPC Configuration . . . . . . . . . . . . . . 75

MODE:D fC 0 When controlling an extraction turbine, set this parameter equal to

the companion Extraction Controller’s Controller ID Number.
Extraction Controller ID
Range: Off disables extraction control interface
1 to 8 selects companion Extraction Controller
Display: fC0 OFF/#
Reference: Extraction Control Interface . . . . . . . . . . . . . 104

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138 Appendix A: Configuration Parameters

MODE:D fE 1 This parameter determines whether the controller will operate in its
redundant mode when a Track discrete input is asserted.
Redundant Tracking
Range: Off redundant tracking disabled
On redundant tracking enabled
Display: fE1 OFF/ON
Reference: Redundant Tracking. . . . . . . . . . . . . . . . . . . . 76

MODE:D fE 3 This parameter determines whether the remote set point increases
or decreases when the signal controlling it rises. For a serial remote
Remote Set Point
set point, it must have the same value as the REV 1 parameter of
Reverse
the source controller.
Range: Off SP increases as signal rises
On SP decreases as signal rises
Display: fE3 OFF/ON
Reference: Computer Set Point . . . . . . . . . . . . . . . . . . . . 87
Serial Remote Set Point. . . . . . . . . . . . . . . . . 88
Analog Remote Set Point. . . . . . . . . . . . . . . . 88

MODE:D LOCK 0 If redundant controllers are given the same Computer ID Number
Modbus While Tracking [MODE:D COMM 0 •], this parameter must be disabled so that only
one of them will respond to Modbus data requests to that address. If
they are given different ID numbers, enabling this parameter allows
the Modbus host to monitor both controllers.
Range: Off host cannot monitor tracking controller
On host can monitor tracking controller
Display: LOC0 OFF/ON
Reference: Redundant Tracking. . . . . . . . . . . . . . . . . . . . 76

MODE:D LOCK 2 This parameter defines the level of access (read/write or read-only)
that a host device has to the controller’s Modbus data.
Modbus Write Inhibit
Range: Off read and write access
On read access only
Display: LOC2 OFF/ON
Reference: Modbus/OPC Configuration . . . . . . . . . . . . . . 75

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 Series 3++ Speed Controller 139

MODE:D LOCK 6 This parameter disables the field input circuits of the CPU/IO PCB
Assembly. This feature is included only as an aid to developing,
CPU Inputs Lockout
testing, and demonstrating the Speed Controller and should never
be enabled in an installed, operating controller.
Range: Off CPU/IO PCB I/O functions enabled
On CPU/IO PCB I/O functions disabled
Display: LOC6 OFF/ON
Reference: Disabling Input Signals . . . . . . . . . . . . . . . . . . 54

An installed controller should never be operated with any LOCK 6

Caution: parameter enabled, as that would prevent it from receiving needed
input signals.

MODE:D LOCK 8 This parameter determines which of the speed set points can be
changed via computer communication.
Computer Remote Set
Point Range: Off the local set point
On the remote set point
Display: LOC8 OFF/ON
Reference: Computer Set Point . . . . . . . . . . . . . . . . . . . . 87
Power Set Point . . . . . . . . . . . . . . . . . . . . . . . 98

MODE:D RA # Each of these parameters selects the conditions under which the
corresponding control relay is triggered. If the assigned function is
Relay Assigned
positive, the relay will be activated when the associated condition
Function
exists. If the value is negative, the relay will de-activate.
You can cycle through these parameters by pressing the MODE and
RA keys, then pressing the decimal (•) key repeatedly.
Range: see Table 3-5
Display: RA#±Valu (press HIGH or LOW to select sign,
then press • to select function)
Reference: Control Relays . . . . . . . . . . . . . . . . . . . . . . . . 69

MODE:D REV 2 This parameter determines whether the second analog output signal
(OUT2) increases or decreases as the Second Output Assigned
Second Output
Variable [COND:D OUT 2] increases.
Reverse
Range: Off OUT2 increases as variable rises
On OUT2 decreases as variable rises
Display: REV2 OFF/ON
Reference: Standard Analog Outputs . . . . . . . . . . . . . . . . 61

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140 Appendix A: Configuration Parameters

MODE:D REV 3 This parameter determines whether the third analog output signal
(OUT3) increases or decreases as the Third Output Assigned Vari-
Third Output Reverse
able [COND:D OUT 3] increases.
Range: Off OUT3 increases as variable rises
On OUT3 decreases as variable rises
Display: REV3 OFF/ON
Reference: Standard Analog Outputs. . . . . . . . . . . . . . . . 61

MODE:S ANIN 1 This parameter specifies whether the controller calculates a speed
from the frequency of the first magnetic pickup input signal.
Speed Input 1
Range: Off MPU1 not read
On MPU1 enabled
Display: P1 OFF/ON
Reference: Speed Inputs . . . . . . . . . . . . . . . . . . . . . . . . . 81

MODE:S ANIN 2 This parameter specifies whether the controller calculates a speed
from the frequency of the second magnetic pickup input signal.
Speed Input 2
Range: Off MPU2 not read
On MPU2 enabled
Display: P2 OFF/ON
Reference: Speed Inputs . . . . . . . . . . . . . . . . . . . . . . . . . 81

MODE:S ANIN 3 This parameter specifies whether the controller calculates a speed
from the frequency of the third magnetic pickup input signal.
Speed Input 3
Range: Off MPU3 not read
On MPU3 enabled
Display: P3 OFF/ON
Reference: Speed Inputs . . . . . . . . . . . . . . . . . . . . . . . . . 81

MODE:S ANIN 4 When all three magnetic pickup inputs are enabled, this parameter
defines their maximum acceptable deviation from the median speed.
MPU Tolerance
Any input that deviates from the median by more than this amount is
considered to have failed.
Range: 01 to 99 rpm
Display: WIN ##
Reference: MPU Tests . . . . . . . . . . . . . . . . . . . . . . . . . . . 83

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 Series 3++ Speed Controller 141

MODE:S ANIN 5 This parameter defines the number of speed input pulses the con-
troller will expect to receive per revolution of the MPU gear shaft.
Gear Tooth Count
Range: 000 to 999 teeth
Display: GR ###
Reference: Scaling and Normalization . . . . . . . . . . . . . . . 82

MODE:S ANIN 6 This parameter defines the number of times the MPU gear shaft
rotates per revolution of the turbine.
Shaft Speed Ratio
Range: 0.000 to 9.999
Display: Ri #.###
Reference: Scaling and Normalization . . . . . . . . . . . . . . . 82

MODE:S fC 1 This parameter enables or disables the cascade/limiting control

loop. If it is enabled, the Limiting Control [MODE:S MVAR] parame-
Cascade / Limiting
ter selects that loop’s function.
Loop
Range: Off cascade and limiting control disabled
On cascade or limiting control enabled
Display: fC1 OFF/ON
Reference: Cascade / Limiting Loop . . . . . . . . . . . . . . . . . 89
Cascade Control . . . . . . . . . . . . . . . . . . . . . . . 90
Limiting Control. . . . . . . . . . . . . . . . . . . . . . . . 91
Power Set Point . . . . . . . . . . . . . . . . . . . . . . . 98

MODE:S fC 2 Enabling this parameter makes it possible to initiate the overspeed

Overspeed Trip Test trip test and display the Overspeed Menu (see DS3307/O).
Range: Off overspeed trip test unavailable
On overspeed trip test available
Display: fC2 OFF/ON
Reference: Overspeed Trip Test . . . . . . . . . . . . . . . . . . . . 68
Overspeed Trip Test . . . . . . . . . . . . . . . . . . . 114

MODE:S fC 4 This parameter specifies the companion Series 3++ Performance or

Dual-Loop A/P Controller from which the speed control loop
Serial Remote Set
receives its serial remote set point.
Point
Range: Off no serial remote set point
1 to 8 Controller ID of source controller
Display: fC4 OFF/#
Reference: Serial Remote Set Point . . . . . . . . . . . . . . . . . 88

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142 Appendix A: Configuration Parameters

MODE:S fC 5 The parameter enables or disables the generator control features.

Generator Control Range: Off generator control disabled
On generator control enabled
Display: fC5 OFF/ON
Reference: Basic Operation . . . . . . . . . . . . . . . . . . . . . . . 93

MODE:S fC 6 If Generator Control [MODE:S fC 5] is enabled, this parameter

determines how the droop control algorithm calculates the genera-
MW Droop Control
tor’s power output.
Range: Off power calculated from power demand
On power calculated from measurement
Display: fC6 OFF/ON
Reference: Basic Operation . . . . . . . . . . . . . . . . . . . . . . . 93
Megawatt Droop. . . . . . . . . . . . . . . . . . . . . . . 99
Valve Droop . . . . . . . . . . . . . . . . . . . . . . . . . 100

MODE:S fC 7 This parameter determines whether the droop control algorithm

uses SV6 (the signal variable for analog input CH6) or the Maximum
Remote Maximum
Load [SPEC:S b 3] parameter as its maximum load limit.
Load Limit
Range: Off Maximum Load
On SV6
Display: fC7 OFF/ON
Reference: Load Limits. . . . . . . . . . . . . . . . . . . . . . . . . . . 98

MODE:S fD 3 3 This parameter determines how the controller will respond if the
generator breaker of a turbine-driven generator opens. If it is
Breaker Shutdown
enabled, an emergency shutdown will be initiated. Otherwise, the
Fallback
controller will switch to isochronous control (if necessary), reduce its
speed control response to the Minimum Demand Clamp [COND:S
OUT 1 LOW], and initialize the local set point to the speed selected
by the Breaker Rated Fallback [MODE:S fD 3 4].
Range: Off isochronous control
On emergency shutdown
Display: fD33 OFF/ON
Reference: Breaker Fallback . . . . . . . . . . . . . . . . . . . . . 101

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 Series 3++ Speed Controller 143

MODE:S fD 3 4 If the generator breaker of a turbine-driven generator opens and the

Breaker Shutdown Fallback [MODE:S fD 3 3] is disabled, the con-
Breaker Rated Fallback
troller will switch to isochronous control, reduce its speed control
response to its Minimum Demand Clamp [COND:S OUT 1 LOW],
and initialize the speed set point to the level (Rated Speed [COND:S
LVL 4] or Minimum Governor [COND:S SP LOW]) specified by this
parameter.
Range: Off Minimum Governor
On Rated Speed
Display: fD34 OFF/ON
Reference: Breaker Fallback. . . . . . . . . . . . . . . . . . . . . . 101

MODE:S LOCK 6 1 This parameter disables the I/O functions of the Auxiliary PCB
Assembly. This feature is included only as an aid to developing,
Auxiliary I/O Lockout
testing, and demonstrating the Speed Controller and should never
be enabled in an installed, operating controller.
Range: Off Auxiliary PCB I/O enabled
On Auxiliary PCB I/O disabled
Display: LC61 OFF/ON
Reference: Disabling Input Signals . . . . . . . . . . . . . . . . . . 54

An installed controller should never be operated with any LOCK 6

Caution: parameter enabled, as that would prevent it from receiving needed
input signals.

MODE:S LOCK 6 2 Enabling this parameter configures the controller to ignore all of its
magnetic pickup speed inputs. This should be done only when using
Speed Inputs Lockout
a computer running one of our various controller support programs
to test or demonstrate the operation of the controller.
Range: Off enabled MPUs are read
On no MPUs are read
Display: LC62 OFF/ON
Reference: Disabling Input Signals . . . . . . . . . . . . . . . . . . 54

An installed controller should never be operated with any LOCK 6

Caution: parameter enabled, as that would prevent it from receiving needed
input signals.

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144 Appendix A: Configuration Parameters

MODE:S LOCK 9 This parameter identifies what model Series 3++ Controller is provid-
ing the serial remote set point.
Dual-Loop/
Performance RSP Range: Off Performance Controller
On Dual-Loop A/P Controller
Display: LOC9 OFF/ON
Reference: Serial Remote Set Point. . . . . . . . . . . . . . . . . 88

MODE:S MOR 1 Even if Manual Operation [MODE:S MOR 2] is enabled and

selected, the controller will automatically reduce the steam flow
Manual Override
whenever the rotational speed is above Maximum Governor
[COND:S SP HIGH], unless this parameter is enabled to allow the
operator to manually override that protective feature.
Range: Off no manual above Maximum Governor
On manual override allowed
Display: MOR1 OFF/ON
Reference: Manual Override . . . . . . . . . . . . . . . . . . . . . 105

MODE:S MOR 2 This parameter enables or disables manual controller operation.

Manual Operation Range: Off manual operation not allowed
On manual operation can be selected
Display: MOR2 OFF/ON
Reference: Manual Operation . . . . . . . . . . . . . . . . . . . . 105

MODE:S MVAR If the Cascade / Limiting Loop [MODE:S fC 1] is enabled, this

Limiting Control parameter determines whether cascade, high limiting, or low limiting
control is applied to the performance control variable (PCV).
Range: Off cascade control of PCV
High high limiting control of PCV
Low low limiting control of PCV
Display: MVR OFF/ON
Reference: Cascade / Limiting Loop . . . . . . . . . . . . . . . . 89
Cascade Control . . . . . . . . . . . . . . . . . . . . . . 90
Limiting Control . . . . . . . . . . . . . . . . . . . . . . . 91
Power Set Point . . . . . . . . . . . . . . . . . . . . . . . 98

MODE:S REV 1 This parameter matches the direction of the actuator control signal
to that of your steam control valve.
Output Reverse
Range: Off signal-to-open valve
On signal-to-close valve
Display: REV1 OFF/ON
Reference: Output Reverse . . . . . . . . . . . . . . . . . . . . . . 106

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 Series 3++ Speed Controller 145

MODE:S SS 1 This parameter determines which variable the speed control loop
uses as the argument for its Proportional Band Characterizer
Characterizer
[COND:S f(X) 1 #], Reset Rate Characterizer [COND:S f(X) 2 #],
Argument
and Dead-Zone Characterizer [COND:S f(X) 3 #].
Range: Off rotational speed
On control response (valve position)
Display: SS1 OFF/ON
Reference: Speed Control Loop . . . . . . . . . . . . . . . . . . . . 86
Isochronous Control . . . . . . . . . . . . . . . . . . . . 94
Droop Control . . . . . . . . . . . . . . . . . . . . . . . . . 96

PID:C G This parameter defines the rate at which the set point ramps when
the cascade loop is toggled from manual to automatic operation.
PCV Set Point Ramp
Rate Range: 0.00 to 9.99 repeats/minute
Display: G #.##
Reference: Performance Set Point . . . . . . . . . . . . . . . . . . 91

PID:C Kr 1 This parameter defines the integral action coefficient for the cas-
cade/limiting control loop.
PCV Reset Rate
Range: 00.0 to 99.9 repeats/minute
Display: Kr1 ##.#
Reference: Cascade / Limiting Loop . . . . . . . . . . . . . . . . . 89

PID:C PB 1 This parameter defines the proportional band coefficient for the cas-
cade/limiting control loop.
PCV Proportional Band
Range: 006 to 999
Display: PB1 ###
Reference: Cascade / Limiting Loop . . . . . . . . . . . . . . . . . 89

PID:C r 1 This parameter defines the maximum amount by which the perfor-
mance control variable can deviate from its set point without causing
PCV Dead-Zone Bias
the cascade control loop to change its control response (in other
words, the half-width of that loop’s dead zone).
Range: 00.0 to 99.9 percent of scale
Display: r1 ##.#
Reference: Dead Zones . . . . . . . . . . . . . . . . . . . . . . . . . . 85
Cascade Control . . . . . . . . . . . . . . . . . . . . . . . 90

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146 Appendix A: Configuration Parameters

PID:C Td 1 This parameter sets the derivative action time constant for the
cascade/limiting loop.
PCV Derivative
Coefficient Range: 0.00 to 9.99 seconds
Display: Td1 #.##
Reference: Cascade / Limiting Loop . . . . . . . . . . . . . . . . 89

PID:C Tf 1 This parameter sets the first order lag time constant for the software
filter applied to the performance (cascade/limiting) control variable
PCV Filter Time
and the droop control power measurement.
Constant
Range: 00.0 to 99.9 seconds
Display: Tf1 ##.#
Reference: Performance Control Variable . . . . . . . . . . . . 90
Megawatt Droop. . . . . . . . . . . . . . . . . . . . . . . 99

PID:S G 1 This parameter defines the rate at which the speed set point is
General Set Point ramped when automatic control is resumed or when you switch from
the local to the remote or cascade set point.
Ramp Rate
Range: 000 to 999 rpm/second
Display: G1 ###
Reference: Computer Set Point . . . . . . . . . . . . . . . . . . . . 87
Local Set Point . . . . . . . . . . . . . . . . . . . . . . . . 87
Speed Set Point . . . . . . . . . . . . . . . . . . . . . . . 87
Start-Up Sequence . . . . . . . . . . . . . . . . . . . 109

PID:S G 2 This parameter defines the rate at which the start-up sequence
Actuator Ramp Rate increases the speed control response until the turbine reaches its
Minimum Control Speed [COND:S DISPLAY LOW].
Range: 0.00 to 9.99 percent/second
Display: G2 #.##
Reference: Start-Up Sequence . . . . . . . . . . . . . . . . . . . 108

PID:S Kr 1 This parameter defines the integral action coefficient for the speed
control loop.
Speed Reset Rate
Range: 00.0 to 99.9 repeats/minute
Display: Kr1 ##.#
Reference: Speed Control Loop . . . . . . . . . . . . . . . . . . . . 86
Isochronous Control . . . . . . . . . . . . . . . . . . . . 94

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 Series 3++ Speed Controller 147

PID:S Kr – This parameter defines the integral action coefficient for the droop
control loop.
Droop Reset Rate
Range: 00.0 to 99.9 repeats/minute
Display: Kr- ##.#
Reference: Droop Control . . . . . . . . . . . . . . . . . . . . . . . . . 96

PID:S PB 1 This parameter defines the proportional band coefficient for the
speed control loop.
Speed Proportional
Band Range: 006 to 999
Display: PB1 ###
Reference: Speed Control Loop . . . . . . . . . . . . . . . . . . . . 86
Isochronous Control . . . . . . . . . . . . . . . . . . . . 94

PID:S PB – This parameter defines the proportional band constant for the droop
control loop.
Droop Proportional
Band Range: 006 to 999
Display: PB- ###
Reference: Droop Control . . . . . . . . . . . . . . . . . . . . . . . . . 96

PID:S r 1 This parameter defines the maximum amount by which the rota-
Speed Dead-Zone Bias tional speed can deviate from its set point without causing the speed
control loop to change its control response (in other words, the half-
width of that loop’s dead zone).
Range: 0 to Maximum Control Speed
Display: r1 #####
Reference: Dead Zones . . . . . . . . . . . . . . . . . . . . . . . . . . 85
Speed Control Loop . . . . . . . . . . . . . . . . . . . . 86
Isochronous Control . . . . . . . . . . . . . . . . . . . . 94
Droop Control . . . . . . . . . . . . . . . . . . . . . . . . . 96
Droop Dead Zone . . . . . . . . . . . . . . . . . . . . . . 96

PID:S r – This parameter defines the maximum amount by which the speed
can deviate from the Rated Speed without causing the droop control
Sync Speed Dead-
loop to change its control response (in other words, the half-width of
Zone Bias
that loop’s dead zone).
Range: 0 to Maximum Control Speed
Display: r- #####
Reference: Droop Dead Zone . . . . . . . . . . . . . . . . . . . . . . 96

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148 Appendix A: Configuration Parameters

PID:S Td 1 This parameter sets the derivative action time constant (in seconds)
for the speed control loop.
Speed Derivative
Coefficient Range: 0.00 to 9.99 seconds
Display: Td1 #.##
Reference: Speed Control Loop . . . . . . . . . . . . . . . . . . . . 86
Isochronous Control . . . . . . . . . . . . . . . . . . . . 94

PID:S Td – This parameter defines the derivative action time constant for the
droop control loop.
Droop Derivative
Coefficient Range: 0.00 to 9.99 seconds
Display: Td- #.##
Reference: Droop Control. . . . . . . . . . . . . . . . . . . . . . . . . 96

PID:S Tf 4 This parameter sets the first-order-lag time constant for the software
filter applied to the speed control loop’s remote set point.
RSP Filter Time
Constant Range: 00.0 to 99.9 seconds
Display: Tf4 ##.#
Reference: Speed Set Point . . . . . . . . . . . . . . . . . . . . . . . 87

SPEC:S b 1 This parameter defines the minimum load for the droop control algo-
rithm and the minimum value for the cascade set point (which is the
Minimum Load
cascade control loop’s output).
Range: 00.0 to 100.0 percent
Display: b1 ##.#
Reference: Cascade Control . . . . . . . . . . . . . . . . . . . . . . 90
Load Limits. . . . . . . . . . . . . . . . . . . . . . . . . . . 98

SPEC:S b 3 This parameter defines the maximum load for the droop control
algorithm and the maximum value for the cascade set point (that is,
Maximum Load
the output of the cascade control loop).
Range: 00.0 to 100.0 percent
Display: b3 ##.#
Reference: Cascade Control . . . . . . . . . . . . . . . . . . . . . . 90
Load Limits. . . . . . . . . . . . . . . . . . . . . . . . . . . 98

SPEC:S K This parameter defines the gain used by the valve and kilowatt
droop control algorithms.
Droop Control Gain
Range: 00.0 to 100.0
Display: DRP ##.#
Reference: Droop Control. . . . . . . . . . . . . . . . . . . . . . . . . 95

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UM3307 Series 3++ Speed Controller

Appendix B Controller Test Sequences

This appendix describes the controller test procedures that can be
executed from the Engineering Panel.
Each such key sequence begins with a data group key that selects
the function of the second key. Unlike configuration sequences,
most of these procedures are not assigned to specific data pages,
so a data page letter (for example, MODE:D ANIN –) is indicated
only if you must press the data group key as many times as needed
to display that letter at the end of the first step confirming display.
Pressing the CLEAR key will terminate any of these procedures and
clear the display. Otherwise, they time out and automatically clear
the display after 45 seconds of keyboard inactivity.

COND:S SP 3 This procedure displays and optionally resets the Overspeed Menu
“MaxN” variable, which is the highest turbine speed detected by the
Maximum Recorded
controller.
Speed
To display its current value (#####), press the following keys:

repeat COND until you see COND: S

3

SP
HI #####
Then press CLEAR to leave this value unchanged, or enter zero to
reset it to zero:

CLEAR

0
or HI 00000
ENTER

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MODE:D ANIN – This procedure can be used to determine whether failed analog
inputs (which trigger “Tran# Fail” alarms) are above or below their
Transmitter Status Test
acceptable ranges.
To initiate this test, press the following keys:

repeat MODE until you see MODE: D

–
AN IN
AN1 GOOD
or AN1 HIGH
or AN1 LOW
The digit in this display is the analog input channel number (AN1).
HIGH indicates that signal is above its Analog Input High Alarm
Limit, LOW indicates it is below its Analog Input Low Alarm Limit, or
GOOD indicates it is between those limits.
You can determine the status of each consecutive input signal by
pressing the • key:
•
AN2 GOOD
or AN2 HIGH
or AN2 LOW
This allows you to repetitively cycle through all the inputs.

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MODE COMM To restart the control program without initializing its operating state
and variables (see MODE TEST 6 on page 159), press the following
Reset Controller
keys:

MODE COMM ENTER

Reset
MODE COMM – 3 To identify the companion controllers from which Port 1 transmis-
sions are being received, press the following keys:
Serial Port 1 Test
– 3
MODE COMM
-1 GOOD
or -1 BAD
where the digit is a controller ID number. GOOD indicates data is
being received from that controller, BAD indicates it is not. Subse-
quently pressing the decimal key displays the same information for
the next possible companion controller. You can cycle through all
eight possible ID numbers (including this controller’s own) by press-
ing that key as many times as you like:
•
-8 BAD
•
-1 GOOD
Although transmissions are normally received from all controllers
connected to Port 1 (including this one), only those from specified
Note: companion controllers are normally of any concern. Failure to
receive an expected transmission will trigger a “Com1 Error” alarm.

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152 Appendix B: Controller Test Sequences

MODE LOCK 3 • This procedure copies the controller’s current parameters into any of
its three alternate sets.
Store Alternate
Parameters To initiate this procedure, which you can abort at any time by press-
ing CLEAR, press the following keys:
3 •
MODE LOCK ENTER
Store1?
This display indicates which alternate set the current parameters will
be copied into. To select a different set, press the decimal (•) key:
•
Store2?
Pressing ENTER will then copy the current parameters to the indi-
cated alternate set and briefly display that set’s new checksum:

ENTER
CS= F882
MODE LOCK 3 • • This procedure copies any of the three alternate parameter sets into
the controller’s current set.
Recall Alternate
Parameters To initiate this procedure, which you can abort at any time by press-
ing CLEAR, press the following keys:
3 • •
MODE LOCK ENTER
Recall1?
This display indicates which alternate set will be copied into the
working memory. To select a different set, press the decimal (•) key:
•
Recall2?
Pressing ENTER will then initiate a recall of the selected alternate
parameter set. If it is valid, it is copied into the current set and the
controller executes a soft reset. If the selected set is invalid (which
probably means it was never defined), “No Match” is displayed to
inform you that the recall has been aborted:

ENTER
Reset
or No Match

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 Series 3++ Speed Controller 153

MODE LOCK 4 This procedure displays the checksum values of the controller’s
various parameter sets. You can determine which (if any) of the
Parameter Checksum
alternate parameter sets is currently in use by comparing the check-
sum of the Present and Long-Term sets to those for the alternate
sets. You can also tell if any of these parameter sets agree with
those recorded on a parameter worksheet by comparing these
checksums to those recorded on that worksheet.
To view the parameter checksums, press the following keys:
4
MODE LOCK
CS= F882
or P = A76F
If the confirming display beings with CS, the present parameter set
is the same as that stored in long-term memory. If that display
begins with P, the two sets differ and the checksum shown is for the
present set. In that case, you can display the long-term parameter
checksum by pressing the decimal key:
•
L = A3C2
If the two parameter sets are different, you should use the Disable
Reconfiguration [MODE LOCK 5 0] procedure to disable reconfigu-
ration. The controller will then correct any errors that occur in the
present parameter set.
To display the Alternate Parameter Set checksums, continue to
press the decimal (•) key:
•
CS1=B94A
•
CS2=632E
•
CS3=44FC
You can cycle through the displays of all four (or five) checksums by
continuing to press the decimal (•) key as many times as you want.

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154 Appendix B: Controller Test Sequences

MODE LOCK 5 1 To enable alteration of the controller’s configuration and tuning

parameters from the Engineering Panel, press the following keys:
Enable Reconfiguration
5 1
MODE LOCK
LOC5 ON
ENTER

If you make a mistake entering this sequence, the controller will

beep and display an Error! message on the confirming display.
When you finish reconfiguring your controller, enter the Disable
Reconfiguration [MODE LOCK 5 0] sequence to disable further
changes (otherwise, reconfiguration will be automatically disabled
after thirty minutes of keyboard inactivity):

MODE LOCK 5 0 To disable alteration of the controller’s configuration and tuning

parameters from the Engineering Panel, press the following keys:
Disable
Reconfiguration 5 0
MODE LOCK
LOC5 OFF
ENTER

If you make a mistake entering this sequence, the controller will

beep and display an Error! message on the confirming display.

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 Series 3++ Speed Controller 155

MODE TEST 2 This procedure displays the installed control program and the FPGA
Program Version and Auxiliary PCB firmware revision numbers.
To determine which revision of the control program is installed in
your controller, press the following keys:
2
MODE TEST 10611063-005
Pressing the decimal key (•) will then display the Auxiliary PCB ver-
sion number:
•
SPBD-010
If your controller is not equipped with this assembly (or it is malfunc-
tioning), this test displays a series of dashes:
•
SPBD----
Pressing the decimal key (•) one more time will display the installed
version of the FPGA firmware:
•
HW01.02A
MODE TEST 3 To view a dynamic display of a specific serial port’s communications
activity, press the following keys:
Serial Port Activity Test
3 #
MODE TEST
PT# R-T_
where # is the numeric key corresponding to the port number. The
bar after the R will be in the high position if that port is receiving a
transmission, otherwise it will be low. Similarly, the bar after the T
will be high only when that port is transmitting. The port in the above
example is receiving but not transmitting.
You can then check for communications activity on any other port by
pressing the corresponding numeric key (for example, press 4 to
view Port 4’s activity):
4
PT4 R-T_

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156 Appendix B: Controller Test Sequences

MODE TEST 4 This procedure can display the current values of the analog, speed
(frequency), position, and discrete input signals, the intended states
Input Signal Values
of the control relays, and the currently-pressed front-panel buttons
and control keys.

The internal analog inputs for the standard analog output loopback
Note: measurements, CPU/IO power supply voltages and temperature
can only be monitored via the via the front-panel status screen.

To initiate this test, press the following keys:

4
MODE TEST
Inputs
To display the measured value of any analog input, press the corre-
sponding numeric key. For example, pressing 1 displays the current
value of the CH1 input:
1
CH1 45.8
where the number in the display is the corresponding signal variable
(values above 99.9 percent display as A0.0). Or, you can display the
value of each consecutive input by pressing the decimal key (•).
To determine if an input is being read accurately, disable its Offset
Zero Input parameter and compare the resulting TEST 4 value to a
volt or ammeter measurement of the corresponding input signal.

The engineering-units value of each measured variable can be dis-

Note: played via the Analog In menu of the front-panel status screen.

To display the speed/frequency inputs (MPUs), press the decimal

key to scroll past the CH8 input display:

CH8 50.8
•
PU1 00.0
These are shown as percentages of the Maximum Control Speed.

The revolutions-per-minute value of each enabled speed input can

Note: be displayed via the In/Out menu of the front-panel status screen.

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 Series 3++ Speed Controller 157

To display the Auxiliary PCB’s position inputs and the high-current

output loopback signal, scroll past the display for MPU 3:

PU3 00.0
•
LV1 35.2
•
AD3 50.3
•
AD4 00.0
•
AD5 01.1
These values represent:
LV1 unscaled LVDT1 input, displayed as a percentage
of its maximum range
AD3 raw value of the output loopback signal,
in percent of 200 mA.
AD4 auxiliary analog input (00.0 = -20, A0.0 = +20 mA)
AD5 output loopback value, after applying the Loop-
back Scaling Bias and Loopback Scaling Gain
To determine the status of the discrete inputs, press zero (0). Press-
ing the decimal key (•) then repeatedly toggles the display between
inputs 1 to 8 and 9 to 16:
0
_2__5___
•
_A__DE__
•
_2__5___
Each character will be the input number if that input is asserted or
an underscore if it is not. Digits above nine are shown in a modified
hexadecimal notation (A=10, B=11, …, G=16). The above examples
show only inputs DI2, 5, 10 (A), 13 (D), and 14 (E) are asserted.

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158 Appendix B: Controller Test Sequences

To determine which control relays are activated, press nine (9):

9
1__4____
where each character will be either the relay number (if that relay is
activated) or an underscore (if it is not). The 1 for fault relay CR1 will
appear unless it (and possibly CR2) are de-activated by CR1’s
assigned function. In the above example, only the fault relays and
CR4 should be activated.

The status of the Auxiliary PCB Fault relay (DO9) cannot be viewed
Note: via this procedure.

To display a group of digits indicating which front-panel keys and

buttons are pressed, press the minus (–) key:
–
12__5___
If no keys are pressed, a line of eight underscores is displayed. If a
single key is pressed or stuck, one of the following unique groups of
digits will appear (for example, the group 1/2/5 shown above would
indicate that only the Menu button is pressed or stuck down):

1356 8 4

12456 125 5

235 346 6

12346 127 1

237 7 2

This procedure does not disable the normal operation of the

Caution: front panel keys and buttons, so pressing them to verify that
they are working can affect the operation of the controller.

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 Series 3++ Speed Controller 159

MODE TEST 6 Resetting the main CPU restarts its control program. A soft reset
occurs when critical parameters are changed or alternate parameter
CPU Reset Count
sets are recalled, the controller is reconfigured from a workstation,
or the Reset Controller [MODE COMM] procedure is executed. This
procedure checks the controller’s parameters to make sure they are
reasonable, resets its serial ports and analog inputs, and begins a
new scan. It does not change the operating state or outputs.
A hard reset, which also triggers an emergency shutdown, occurs
when the controller is first powered up, after a power interruption, or
when a hardware or software fault causes a watchdog time out.
To display the number of times the control program has restarted
since this count was last zeroed, press the following keys:
6
MODE TEST
Z80 ####
where #### is the reset count, which can then be reset by pressing
the zero key:
0
Z80 0000

MODE TEST 7 To display the number of times the front-panel microprocessor has
reset since this count was last zeroed, press the following keys:
Front-Panel Reset
Count 7
MODE TEST
Mot ####
where #### is its current value, which can then be reset by pressing
the zero key:
0
Mot 0000

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160 Appendix B: Controller Test Sequences

MODE TEST 8 This procedure initiates the calculation and display of a four-digit,
hexadecimal (for example, 1AF4) checksum for the controller’s
Program Checksum
internal binary operating instructions. It is used primarily to verify the
successful downloading of a new operating program.
To initiate this test, press the following keys. The checksum will be
displayed after a brief pause:
8
MODE TEST
CRC BusY
CRC ####
where #### is the checksum for the installed software. The Series
3++ Speed Controller [DS3307/V] provides the correct CRCs for
various software revisions.

MODE TEST 9 This procedure sets a Speed Controller’s clock to a specified month,
day, year, hour and minute, which it displays in that order. As the
Set Clock
current value of each field is displayed, you can:
• press the decimal key (•) to leave it unchanged and display the
next field’s value,
• enter a new value by pressing the corresponding two numeric
keys and then the ENTER key, or
• press the CLEAR key to terminate this procedure.
If you make a mistake while specifying a new value, press the
CLEAR key once to start over or twice to abort this procedure and
leave the original value unchanged. If you specify an invalid value
and then press ENTER, the procedure aborts after briefly displaying
an “Error!” message. Once you have entered a change, making an
error or aborting the procedure will not undo it.
To initiate this procedure, press the following keys to display the cur-
rent month-of the-year setting (01##12):
9
MODE TEST
Month?##
Either pressing the decimal key (•) or entering a new month will then
display the current day-of-the-month (01##days in month):
# #
Month?##
ENTER
Day? ##
where each numeric key used to specify the new month is repre-
sented as # (you must press the leading zero for most months).

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 Series 3++ Speed Controller 161

Either pressing the decimal key (•) or entering a new day will then
display the current year (20##):
# #
Day? ##
ENTER
Year? ##
Either pressing the decimal key (•) or entering a new year will then
display the current hour-of-the-day (00##59):
# #
Year? ##
ENTER
Hour? ##
Pressing the CLEAR key or entering a new minute (00##59) will
then terminate this procedure. Entering a new minutes value will
also set the seconds counter to zero:
# #
Minut?##
ENTER

MODE TEST HIGH This procedure dynamically displays the number of times the Auxil-
iary PCB has failed to respond to the CPU/IO PCB since this count
Auxiliary PCB Error
was last zeroed.
Count
To display this count, press the following keys:
HIGH
MODE TEST
332=XXXX
where #### is the communication error count, which can then be
reset by pressing the zero key:
0
332=0000

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 Series 3++ Speed Controller 163

UM3307 Series 3++ Speed Controller

Index
A Accumulated Integral Response
General PID Algorithm . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 85
Actuator Control Signal
Assigning to Analog Outputs. . . . . . . . . . . . . . . . . . . . . . . . . 59
Configuring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 106
Alarm
Controller Status Indicators. . . . . . . . . . . . . . . . . . . . . . . . . . 47
External Alarms. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69
Alternate Parameter Sets
Checksums . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 153
Storing and Recalling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 152
Analog Input
Configuration. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55–58
Disabling Input Signals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54
Monitoring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49
Signal Values Test . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 156
Analog Output
Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59
Monitoring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49
Standard Analog Outputs . . . . . . . . . . . . . . . . . . . . . . . . . . . 61
Analog-to-Digital Variable
Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56
Antisurge Controller
Applications. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
Variable-Speed Load . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
Automatic Operation
Continuous Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
Discrete Inputs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 66
Restoring. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45
Automatic Sequences
Automatic Sequences . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 107
Coordinated Sequencing. . . . . . . . . . . . . . . . . . . . . . . . . . . 112
Discrete Inputs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67
Sequencing Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35
Auxiliary PCB
Auxiliary PCB Error Count. . . . . . . . . . . . . . . . . . . . . . . . . . 161
Auxiliary PCB Revision . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54
Fault Relays . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69
Faults . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47
Hardware Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53
B Bipolar Output

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164 Index

Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60
Board Temperature
Monitoring Internal Conditions . . . . . . . . . . . . . . . . . . . . . . . 48
Breaker Fallbacks
Breaker Fallbacks. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 101
Bumpless Transfer
General PID Algorithm . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 85
Initiating Cascade Control . . . . . . . . . . . . . . . . . . . . . . . . . . 29
Performance Set Point . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 91
Restoring Automatic . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45
Serial Remote Set Point . . . . . . . . . . . . . . . . . . . . . . . . . . . . 88
Speed Set Point . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 87
C Cascade Control
Cascade/Limiting Loop . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 89
Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 90
Droop Set Point . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 98
Variable-Speed Load . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
Cascade Set Point
Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 88
Discrete Inputs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 66
Selection and Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
Set Point Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
Cascade/Limiting Control Loop
Cascade/Limiting Loop . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 89
Compressor Control
Applications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
Serial Remote Set Point . . . . . . . . . . . . . . . . . . . . . . . . . . . . 88
Computer Communications
Manual Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44
Modbus Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 75
Operator Interfaces. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
Redundant Tracking . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 76
Serial Ports . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 74
Speed Set Point . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 87
Computer ID Number
ID Numbers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 75
Redundant Tracking . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 76
Computer Inhibit
Modbus Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 75
Configuration
Enabling and Disabling. . . . . . . . . . . . . . . . . . . . . . . . . . . . 154
Parameter Checksum. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 153
Viewing and Changing Parameter Values . . . . . . . . . . . . . 117
Control Key

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 Series 3++ Speed Controller 165

Signal Values Test . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 158

Control Range
Turbine Speed Profile . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 78
Control Relay
Configuration. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69
Monitoring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50
Signal Values Test . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 158
Speed Switches . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 80
Control Response
Control Response . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 92
Demand Clamps . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 104
Control Valve
Analog Output . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59
Monitoring Position . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
Output Reverse . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 106
Positioning. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62
Controller ID Number
ID Numbers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 75
Redundant Tracking . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 76
Controller Reset
CPU Reset Count . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 159
Fault Indicators . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47
MODE COMM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 151
CPU/IO PCB
Analog Inputs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55
Faults . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47
FPGA Firmware Revision . . . . . . . . . . . . . . . . . . . . . . . . . . . 54
Hardware Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53
Critical Speed
Configuring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 79
Critical Speed Avoidance . . . . . . . . . . . . . . . . . . . . . . . . . . 111
Critical Speed Stalling . . . . . . . . . . . . . . . . . . . . . . . . . . 39, 112
D Dead Zone
Cascade Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 90
Droop Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 95
General PID Algorithm . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 85
Speed Control Loop . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 86
Synchronous Speed . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 96
Debounce, Discrete Inputs . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64
Demand Clamp
Automatic Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
Demand Clamps . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 104
Extraction Control Interface. . . . . . . . . . . . . . . . . . . . . . . . . 104
Manual Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44

March 2021 UM3307 (2.1.0)

166 Index

Digital Positioning Module

Series 3++ Applications . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63
Disabling Inputs
Disabling Input Signals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54
Discrete Input
Configuring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64
Debounce . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64
Disabling Input Signals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54
Monitoring. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50
Signal Values Test . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 157
Droop Control Loop
Continuous Operation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
Droop Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 95
Isochronous Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 94
Megawatt Droop . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 99
Mode Selection. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 93
Set Points . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 98
Valve Droop . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 100
Droop Set Point
Enabling and Selecting. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 98
Dual-Loop A/P Controller
Applications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
Coordinated Sequencing . . . . . . . . . . . . . . . . . . . . . . . . . . 112
Variable-Speed Load . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
E Electronic Overspeed Trip
Control Range . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 78
Overspeed Protection. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 113
Emergency Shutdown
Always Enabled (ae) Input . . . . . . . . . . . . . . . . . . . . . . . . . . 67
Sequencing Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39
Stop Sequence . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 110
Engineering Panel
Serial Communication Errors . . . . . . . . . . . . . . . . . . . . . . . . 50
Using . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 117
External Alarms
External Alarms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69
Extraction Control
Extraction Control Interface . . . . . . . . . . . . . . . . . . . . . . . . 104
Extraction Controller
Applications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
Serial Ports . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 74
F Failsafe Timer
Start-Up Sequence . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 109

March 2021 UM3307 (2.1.0)

 Series 3++ Speed Controller 167

Fault
Auxiliary PCB Reset Count . . . . . . . . . . . . . . . . . . . . . . . . . 161
Controller Status Indicators. . . . . . . . . . . . . . . . . . . . . . . . . . 47
CPU Reset Count . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 159
Fault Relays . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69
Indicators. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47
Redundant Tracking . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 76
Field Device Power Test
Fault and Alarm Indicators . . . . . . . . . . . . . . . . . . . . . . . . . . 48
Field Input Module
Hardware Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53
Field Output Module
Hardware Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53
Front Panel
Front Panel Reset Count. . . . . . . . . . . . . . . . . . . . . . . . . . . 159
Operator Interfaces . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
G Generator Breaker
Discrete Inputs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68
Generator Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 93
Generator Control
Applications. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
Breaker Fallbacks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 101
Configuration. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 93
Continuous Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . 26, 32
Discrete Inputs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68
Generator Shutdown . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
Generator Startup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43
Idling a Generator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37
H Hardware Configuration
Hardware Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53
High-Current Output
Bipolar Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60
Configuration. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60
High-Density Interconnect Cables
Hardware Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53
I ID Numbers
ID Numbers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 75
Idle Sequence
Discrete Inputs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67
Ramp to Idle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37
Idle Speed
Configuring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 79
Indicators. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36

March 2021 UM3307 (2.1.0)

168 Index

Idle State
Critical Speed Stalling . . . . . . . . . . . . . . . . . . . . . . . . . . . . 112
Sequencing Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36
Intended Valve Position
Intended Valve Position . . . . . . . . . . . . . . . . . . . . . . . . . . . 103
Manual Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44
Monitoring. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
Internal Power Test
Fault and Alarm Indicators . . . . . . . . . . . . . . . . . . . . . . . . . . 48
Internal Power Supply Failure . . . . . . . . . . . . . . . . . . . . . . . 68
Monitoring Internal Conditions . . . . . . . . . . . . . . . . . . . . . . . 48
Isochronous Control
Continuous Operation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
Discrete Inputs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68
Isochronous Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 94
Mode Selection. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 93
L Limiting Control
Cascade/Limiting Loop . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 89
Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 91
Continuous Operation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
Control Response. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 92
Generator Control. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 93
Limiting Control Threshold . . . . . . . . . . . . . . . . . . . . . . . . . . 92
Load Limit
Cascade Set Point . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 88
Generator Control. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 98
Load Loss Response
Discrete Inputs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67
Overspeed Protection. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 115
Local Set Point
Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 87
Discrete Inputs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 66
Selection and Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
Set Point Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
Loop Reverse
Cascade Control. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 90
Limiting Control. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 91
M Manual Operation
Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 105
Discrete Inputs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 66
Initiating . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44
Manual Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44
Manual Startup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43
Remote Manual Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44

March 2021 UM3307 (2.1.0)

 Series 3++ Speed Controller 169

Manual Override
Configuration. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 105
Manual Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44
Manual Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44
Maximum Governor
Control Response . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 92
Demand Clamps . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 104
Manual Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44
Manual Override . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 105
Normal Operating Range . . . . . . . . . . . . . . . . . . . . . . . . . . . 78
Overspeed Trip Test . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 114
Speed Set Point . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 87
Maximum Recorded Speed
Controller Test Sequences . . . . . . . . . . . . . . . . . . . . . . . . . 149
Overspeed Trip Test . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 114
Measured Variable
Measured Variables . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57
Mechanical Overspeed Trip Speed
Control Range . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 78
Electronic Overspeed Trip. . . . . . . . . . . . . . . . . . . . . . . . . . 113
Overspeed Trip Test . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 115
Megawatt Droop Control
Droop Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 99
Minimum Control Speed
Control Range . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 78
Minimum Governor
Control Response . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 92
Demand Clamps . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 104
Normal Operating Range . . . . . . . . . . . . . . . . . . . . . . . . . . . 78
Speed Set Point . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 87
Modbus Register Scaling
Modbus Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 75
N Normal Operating Range
Turbine Speed Profile . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 78
O Operating Mode
Discrete Inputs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67
Operating Sequences . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 107
Operating State
Discrete Inputs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67
Operating Sequences . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 107
Sequencing Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35
Operator Interface
Modbus Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 75

March 2021 UM3307 (2.1.0)

170 Index

Operator Interface Options . . . . . . . . . . . . . . . . . . . . . . . . . . 25

Operator Workstation
Serial Ports . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 74
Output Loopback Test
Controller Status Indicators . . . . . . . . . . . . . . . . . . . . . . . . . 50
Output Readout
Intended Valve Position . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
Output Reverse
Output Reverse . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 106
Overspeed Protection
Overspeed Prevention . . . . . . . . . . . . . . . . . . . . . . . . . . . . 115
Overspeed Trip Test
Overspeed Protection. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 114
P Parameter Checksum
Parameter Checksum. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 153
Performance Control Variable
Monitoring. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
Performance Controller
Applications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
Coordinated Sequencing . . . . . . . . . . . . . . . . . . . . . . . . . . 112
Serial Ports . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 74
Variable-Speed Load . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
Performance Set Point
Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 91
Viewing and Changing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
Permissive Conditions
Discrete Inputs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67
Start-Up Sequence . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 109
Physical Clamp
Extraction Control Interface . . . . . . . . . . . . . . . . . . . . . . . . 104
Manual Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44
PID Algorithm
General PID Algorithm . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 85
Position Input
Disabling Input Signals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54
Input Signal Values. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 157
Monitoring. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
Valve Position Test. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 106
Positioning Loop
Hardware Options. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53
High-Current Output . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60
Power Demand
Extraction Control Interface . . . . . . . . . . . . . . . . . . . . . . . . 104

March 2021 UM3307 (2.1.0)

 Series 3++ Speed Controller 171

Intended Valve Position . . . . . . . . . . . . . . . . . . . . . . . . . . . 103

Power Input
Megawatt Droop . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 99
Power Set Point
Droop Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 95
Program Checksum
Program Checksum . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 160
Program Version
Program Version . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 155
R Rated Sequence
Discrete Inputs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67
Ramp to Rated . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38
Rated Speed
Configuring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 79
Ready State
Sequencing Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41
Real-Time Clock
Setting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 160
Redundant Controller
Discrete Inputs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67
MPU Testing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 83
Redundant Tracking . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 76
Tracking State . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46
Redundant Selector Power Test
Fault and Alarm Indicators . . . . . . . . . . . . . . . . . . . . . . . . . . 48
RCS Power Failure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68
Remote Control
Analog Outputs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59
Control Functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64
Discrete Inputs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64
Discrete Outputs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69
Operator Interfaces . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
Remote Manual
Discrete Inputs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 66
Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44
Setting Up . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 105
Remote Set Point
Analog Remote Set Point . . . . . . . . . . . . . . . . . . . . . . . . . . . 88
Discrete Inputs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 66
Droop Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 98
Selection and Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
Serial Remote Set Point . . . . . . . . . . . . . . . . . . . . . . . . . . . . 88
Set Point Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27

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172 Index

Reset to Ready
Discrete Inputs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67
Shutdown State . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41
Rotational Speed
Configuring Speed Inputs . . . . . . . . . . . . . . . . . . . . . . . . . . . 81
Controller Status Indicators . . . . . . . . . . . . . . . . . . . . . . . . . 49
Disabling Input Signals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54
Input Signal Values. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 156
Monitoring. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
MPU Testing. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 83
Scaling and Normalization . . . . . . . . . . . . . . . . . . . . . . . . . . 82
Speed Control Loop . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 86
Turbine Speed Profile. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 77
Run State
Continuous Operation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
Variable-Speed Load . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
S Serial Port
Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 74
Fault and Alarm Indicators . . . . . . . . . . . . . . . . . . . . . . . . . . 50
ID Numbers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 75
Serial Communication Errors . . . . . . . . . . . . . . . . . . . . . . . . 50
Serial Communication Formats . . . . . . . . . . . . . . . . . . . . . . 75
Serial Port 1 Test . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 151
Serial Port Activity Text . . . . . . . . . . . . . . . . . . . . . . . . . . . 155
Set Point Mode
Continuous Operation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
Set Point Readout
Speed and Set Point. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
Set Point Source
Discrete Inputs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 66
Ready State . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41
Selecting and Identifying . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
Shutdown Log
Shutdown State . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41
Shutdown State
Sequencing Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41
Signal Variable
Signal Values Test . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 156
Signal Variables . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57
Speed Control
Continuous Operation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
Deviation Alarm . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
Generator Control. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 94
Variable-Speed Load . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31

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 Series 3++ Speed Controller 173

Speed Control Loop

Monitoring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
Speed Control Loop . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 86
Speed Deviation Alarm . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 88
Speed Readout
Speed and Set Point . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
Speed Set Point
Monitoring and Selecting. . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
Speed Set Point . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 87
Speed Switch
Configuring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 80
Monitoring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
Standard Outputs
Configuration. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61
Start-Up Sequence
Automatic Sequences . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 108
Black Starting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43
Discrete Inputs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67
Sequencing Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42
Stop Sequence
Automatic Sequences . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 110
Sequencing Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
T Tracking State
Redundant Tracking . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 76
Tracking State . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46
Transmitter Testing
Controller Status Indicators. . . . . . . . . . . . . . . . . . . . . . . . . . 49
Transmitter Status Test. . . . . . . . . . . . . . . . . . . . . . . . . . . . 150
Transmitter Testing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56
Trip and Throttle Valve
Overspeed Trip Test . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 115
U Utility Breaker
Discrete Inputs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68
Generator Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 93
V Valid Speed Range
Electronic Overspeed Trip. . . . . . . . . . . . . . . . . . . . . . . . . . 113
MPU Testing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 83
Overspeed Trip Test . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 114
Scaling and Normalization . . . . . . . . . . . . . . . . . . . . . . . . . . 82
Turbine Speed Profile . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 78
Valve Droop Control
Valve Droop . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 100
Valve Position Test

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174 Index

Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 106
Controller Status Indicators . . . . . . . . . . . . . . . . . . . . . . . . . 50
Valve Positioning
Digital Positioning Module . . . . . . . . . . . . . . . . . . . . . . . . . . 63
Overview. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62
W Watchdog Time Out
CPU/IO and Auxiliary PCB . . . . . . . . . . . . . . . . . . . . . . . . . . 47

March 2021 UM3307 (2.1.0)

 DS3307/D. Series 3++ Speed Controller

#
Speed Controller
OPC Variables
Controller Version: 1063-005

This data sheet lists and describes the default data items the Series 3 OPC Server provides for
this controller. Cross-references in the descriptions are to the Series 3++ Speed Controller
[UM3307].
Read-Only Data Items
Variable Name Native Type Variable Name Native Type Variable Name Native Type
1V_Power Float Last_ESD1 Short PCV_pos Float
3V_Power Float Limit Boolean Port1Fail Boolean
5V_Power Float Limit_Enabled Boolean Port2Fail Boolean
15V_Power Float Loop Counter Short Position_Fail Boolean
24V_Power Float Low_Clamp Boolean Power Float
Alarm Boolean Low_Voltage Boolean Power% Float
Automatic Boolean Max_Gov Float Power_SP Float
Aux_Board_Fail Boolean Max_Speed Float Power_SP% Float
Board_Temp Float Min_Gov Float Power_hi Float
Cascade Boolean MOR_Active Boolean Power_lo Float
Cascade_Enabled Boolean MPU# Float Power_max Float
CH# Float MPU#_Fail Boolean Power_min Float
CH#_fail Boolean OS_Test Boolean Power_pos Float
CH#_scaled Float Out_Display Float Power_Fallback Boolean
COMM_Status Long Output_Fail Boolean Power_Limit Boolean
Computer_RSP Boolean OUT1_Readback Float PV#hi Float
CRC Short OUT2 Float PV#lo Float
CRZ_Stall Boolean OUT2_Readback Float PV#max Float
DI# Boolean OUT3 Float PV#min Float
DO# Boolean OUT3_Readback Float PV#pos Float
Droop Boolean PCV Float Ready Boolean
FD_24V_Fail Boolean PCV% Float Remote Boolean
Gen_Breaker Boolean PCV_SP Float Reset Boolean
Gen_Enabled Boolean PCV_SP% Float RPM_Display Float
High_Clamp Boolean PCV_hi Float RS_24V_Fail Boolean
Idle1 Boolean PCV_lo Float Run Boolean
Idle2 Boolean PCV_max Float Shutdown Boolean
Idle3 Boolean PCV_min Float SP_Display Float

March 2021 Page 1 of 8 DS3307/D (2.1.0)

Variable Name Native Type Variable Name Native Type Variable Name Native Type
Speed_Dev Boolean Stop Boolean Tran_Fail Boolean
SpeedSwitch# Boolean State Integer Version String
Speed_Track Boolean Tracking Boolean Write_Inhibit Boolean

Read-Write Data Items

Variable Name Native Type Variable Name Native Type Variable Name Native Type
AutomaticW Boolean Manual_TargetW Float RemoteW Boolean
CascadeW Boolean PCV_SPW Float RunW Boolean
ESDW Boolean PCV_SPW% Float Servo#W Boolean
Halt_RampW Boolean Power_SPW Float Speed_SPW Float
Idle1W Boolean Power_SPW% Float StopW Boolean
Idle2W Boolean RatedW Boolean User#W Boolean
Idle3W Boolean ReadyW Boolean

Data Item Descriptions

Clients can access this data by connecting to the TrainTools.S3p_OPC.1 server and prepend-
ing the item names with the COM port number, a colon, the controller’s Computer ID, and a
period (for example, COM1:5.CH1).
1V_Power, 3V_Power, 5V_Power, 15V_Power: Measured output voltages of the 1.2, 3.3, 5.0
and 15 Volt power converters, respectively. See: Internal Conditions in Chapter 2.
24V_Power: Measured voltage of the power provided to the CPU PCB by the power supply
assembly. See: Internal Conditions in Chapter 2.
Alarm: On when there are unacknowledged alarm conditions. See: Controller Health in Chapter
2 and Alarms Menu in DS3307/O.
Automatic and AutomaticW: On when the controller is operating automatically and Off during
manual operation. Setting AutomaticW forces the controller into automatic, clearing it forces
the controller into manual. See: Manual Operation in Chapter 2.
Aux_Board_Fail: On when the main CPU is unable to communicate with the auxiliary/speed
board CPU. See: CPU/IO and Auxiliary PCB Faults in Chapter 2.
Board_Temp: Internal temperature measured by the CPU PCB, in degrees Celsius.
See: Internal Conditions in Chapter 2.
Cascade: On only when the speed or power set point is being calculated from the deviation of
PCV from the PCV_SP. See: Speed and Set Point in Chapter 2.
Cascade_Enabled: On when the PCV control loop is enabled, even if it is not active.
See: Cascade Set Point in Chapter 2.

March 2021 Page 2 of 8 DS3307/D (2.1.0)

CascadeW: On when the cascade speed set point is selected, even if the controller is not using
it (for example, during manual operation). Setting CascadeW forces the speed control loop
to select that set point, clearing it selects the local speed control set point.
See: Speed and Set Point in Chapter 2.
CH#: Percent-of-span value of the corresponding analog input signal variable (each 4 to 20 mA
input signal is compensated for a twenty percent offset). See: Signal Variables in Chapter 3.
CH#_fail: 1 if corresponding raw analog input signal is below its low alarm threshold, 2 if it is
above its high alarm threshold, otherwise 0. Tran_Fail is set if any of these variables have
non-zero values. See: Transmitter Testing in Chapter 3.
CH#_scaled: Value of the corresponding measured variable, calculated by scaling analog input
CH# between PV#lo and PV#hi. See: Measured Variables in Chapter 3.
COMM_Status: 0 (no error) or 1 (if the n most recent Modbus requests timed out. The minimum
number of requests that must time out (n) is set by the server’s “Timeouts Before COMM
Failure” preference (1 by default).
Computer_RSP: If Gen_Enabled is Off, this variable is set when Speed_SPW reports and
changes the remote speed set point. If Gen_Enabled is On, this variable is set when Pow-
er_SPW reports and changes the remote power set point.
See: Speed and Set Point and Droop Operation in Chapter 2.
CRC: 16-bit checksum for the controller’s present set of configuration and tuning parameters.
See: Parameter Checksum in Appendix B.
CRZ_Stall: On when the speed is within a critical zone and the intended valve position is at its
high clamp or under manual control. See: Critical Speed Stall in Chapter 2.
DI#: On when the corresponding discrete input (1#16) is asserted, Off when it is cleared.
See: Discrete Inputs in Chapter 3.
DO#: On when the corresponding control relay (1#8) is supposed to be activated, Off when it
is supposed to be cleared. Bits corresponding to fault relays reflect only the assigned func-
tions and cannot indicate hardware faults. See: Control Relays in Chapter 3.
Droop: On when the controller is regulating a turbine-driven generator’s power output, rather
than its speed and frequency. See: Droop Operation in Chapter 2.
ESDW: On when the controller is operating in its Shutdown state. Setting this bit initiates an
emergency shutdown (and clears Idle1W, Idle2W, Idle3W, RatedW, and StopW), after
which it remains set until the controller is reset to the Ready state by asserting ReadyW,
pressing the Reset key, or asserting a Reset input. See: Emergency Shutdown in Chapter 2.
FD_24V_Fail: On if any discrete input assigned the field device power function clears.
See: Power Supply Failures in Chapter 2.
Gen_Breaker: On when a generator control application’s generator breaker input is asserted.
See: Synchronous Generator in Chapter 2.
Gen_Enabled: On when generator control is enabled, even if it is not active.
See: Synchronous Generator in Chapter 2.
Halt_RampW: Setting this bit to On interrupts any Idle, Rated, or Stop sequence and clears
Idle1W, Idle2W, Idle3W, RatedW, or StopW. See: Sequencing Operation in Chapter 2.

March 2021 Page 3 of 8 DS3307/D (2.1.0)

High_Clamp and Low_Clamp: On when the intended valve position is at or beyond its corre-
sponding upper or lower limit. See: Control Element Position in Chapter 2.
Idle1: On when the speed set point is greater than or equal to the Idle1 Speed and less than the
Idle2 Speed (or Minimum Governor if the Idle2 Speed is zero). See: Idle State in Chapter 2.
Idle1W: On while the speed set point is being ramped to its Idle1 Speed. Setting this bit while
the controller is in its Ready state selects Idle1 as the target for subsequent startups. Setting
it while the turbine is running causes the controller to ramp the speed up or down to that tar-
get speed and halts any other active sequence (thus clearing Idle2W, Idle3W, RatedW, or
StopW). It can not be set while ESDW is. See: Sequencing Operation in Chapter 2.
Idle2: On when the speed set point is greater than or equal to the Idle2 Speed and less than the
Idle3 Speed (or Minimum Governor if the Idle3 Speed is zero). See: Idle State in Chapter 2.
Idle2W: On while the speed set point is being ramped to its Idle2 Speed. Setting this bit while
the controller is in its Ready state selects Idle2 as the target for subsequent startups. Setting
it while the turbine is running causes the controller to ramp the speed up or down to that tar-
get speed and halts any other active sequence (thus clearing Idle1W, Idle3W, RatedW, or
StopW). It can not be set while ESDW is. See: Sequencing Operation in Chapter 2.
Idle3: On when the speed set point is greater than or equal to the Idle3 Speed and less than
Minimum Governor. See: Idle State in Chapter 2.
Idle3W: On while the speed set point is being ramped to its Idle3 Speed. Setting this bit while
the controller is in its Ready state selects Idle3 as the target for subsequent startups. Setting
it while the turbine is running causes the controller to ramp the speed up or down to that tar-
get speed and halts any other active sequence (thus clearing Idle1W, Idle2W, RatedW, or
StopW). It can not be set while ESDW is. See: Sequencing Operation in Chapter 2.
Last_ESD1: Integer identifying the cause of the most recent shutdown:
01: Overspeed trip 32: Shutdown occurred while tracking
02: Front-panel operating mode request 34: Auxiliary/Speed Board failure
04: Failure of all enabled MPUs 64 to 79: ESD field DI number + 63
08: Failsafe shutdown during startup 128: Breaker shutdown
16: Watchdog shutdown (fault) else: unset or corrupted
See: Shutdown State in Chapter 2.
Limit: On when the limiting control loop is reducing the steam flow, or the speed control
response is at its upper or lower demand clamp (extraction applications).
See: Limiting Control and Control Element Position in Chapter 2.
Limit_Enabled: On when the PCV limiting loop is enabled, even if it is not active.
See: Limiting Control in Chapter 2.
Loop Counter: Control loop counter which continuously counts up to 255 and recycles to zero
while the controller is active. Indicates controller activity and is primarily used for testing
purposes.
Low_Voltage: On when any internally-monitored CPU PCB component power voltage is below
its alarm level. See: Power Supply Failures in Chapter 2.

March 2021 Page 4 of 8 DS3307/D (2.1.0)

Manual_TargetW: Intended valve position (percent open). If AutomaticW is cleared (manual
operation selected), writing to this variable changes OUT1 and Out_Display.
See: Manual Operation in Chapter 2.
Max_Speed: Maximum Control Speed [COND:S DISPLAY HIGH] configuration parameter
(read-only), which defines the normalization speed for all speed variables and parameters.
See: Speed Inputs in Chapter 4.
Min_Gov and Max_Gov: Minimum Governor [COND:S SP LOW] and Maximum Governor
[COND:S SP HIGH] configuration parameters (read-only), which define the speeds the
turbine should normally operate between. See: Speed and Set Point in Chapter 2.
MOR_Active: On when the manually specified valve position is being reduced because the
speed is above Max_Gov. See: Manual Operation in Chapter 2.
MPU#: Speed calculated from the corresponding speed input signal, in rpm.
See: Scaling and Normalization in Chapter 4.
MPU#_Fail: On when the corresponding magnetic pickup’s signal is less than the Control
Threshold or outside the deviation window. See: MPU Tests in Chapter 4.
OS_Test: On if the Overspeed Trip Test is enabled. See: Overspeed Trip Test in Chapter 8.
Out_Display: Intended valve position (percent open) displayed by the front-panel OUT readout.
See: Control Element Position and Manual Operation in Chapter 2.
Output_Fail: On if OUT1_Readback deviates from Out_Display (or its compliment, if OUT1 is
reversed) by more than 5.0 percent. See: Output Loopback Test in Chapter 3.
OUT1_Readback: Actual percent-of-span value of the high-current output signal, or the control
valve position measured by the LVDT1 input (if the optional positioning loop is enabled).
See: Control Element Position and Analog Output Signals in Chapter 2.
OUT2 and OUT2_Readback, OUT3 and OUT3_Readback: Intended and actual values of the
standard analog output signals. See: Analog Output Signals in Chapter 2.
PCV: Performance control variable for the cascade or limiting control loop.
See: Cascade Set Point and Limiting Control in Chapter 2.
PCV%: Performance control variable, in percent.
PCV_hi, PCV_lo, PCV_max, PCV_min and PCV_pos: Same as PV1hi, PV1lo, PV1max,
PV1min, and PV1pos (see PV#hi below).
PCV_SP and PCV_SPW: These variables report and PCV_SPW can change the set point or
limiting control threshold for the performance control variable (PCV):
• If Cascade_Enabled is on, they are the cascade loop’s set point. If Cascade is active, that
set point can be changed by writing to PCV_SPW.
See: Cascade Set Point in Chapter 2.
• If Limit_Enabled is On, they are the limiting control threshold.
See: Limiting Control in Chapter 2.
PCV_SP% and PCV_SPW%: Set point or limiting control threshold for PCV, in percent.
Port1Fail: On if the controller fails to receive Port 1 data it has been configured to expect.
See: Serial Communication Errors in Chapter 2.
Port2Fail: Always Off, because Speed Controllers do not use serial Port 2.

March 2021 Page 5 of 8 DS3307/D (2.1.0)

Position_Fail: On if the position feedback test is enabled and CH4 deviates from Out_Display
(or its compliment, if OUT1 is reversed) by more than 5.0 percent.
See: Output and Valve Position Failures in Chapter 2.
Power: This variable reports the measured or calculated electrical power for the droop control
loop, as scaled for the front panel readouts. See: Droop Operation in Chapter 2.
Power%: Measured or calculated electrical power, as a percent of Power_hi.
Power_hi and Power_lo: Scaling range for the Power variable, calculated by applying Power_-
pos to Power_max and Power_min.
Power_max: PV3max (see PV#max below) multiplied by the configured Maximum MW Signal
[COND:D LVL 7].
Power_min and Power_pos: Same as PV3min and PV3pos (see PV#min and PV#pos below).
Power_Fallback: On when the electrical power input fails, in which case Power is estimated
from the intended valve position. See: Droop Operation in Chapter 2.
Power_Limit: On if Power is at or beyond its configured maximum set point.
See: Droop Operation in Chapter 2.
Power_SP and Power_SPW: If Droop is On, these variables report the droop control set point.
If Cascade is On, that set point is controlled by the performance control loop. Otherwise:
• If Computer_RSP and Remote are both Off, the local power set point is in use and can be
changed by writing to Power_SPW or pressing the Raise and Lower keys.
• If Computer_RSP and Remote are both On, the remote power set point is in use and can
be changed only by writing to Power_SPW.
In either case, the new set point will be clamped if the value written to Power_SPW is
beyond its configured range. See: Droop Operation in Chapter 2.
Power_SP% and Power_SPW%: Droop control set point, as a percent of Power_hi.
PV#hi and PV#lo: Scaling range for corresponding CH#_scaled, calculated by applying PV#pos
to PV#max and PV#min. See: Measured Variables in Chapter 3.
PV#max: Measured Variable Maximum [COND:D DISPLAY 0 # HIGH] configuration parameter
for CH#_scaled.
PV#min: Measured Variable Minimum [COND:D DISPLAY 0 # LOW] configuration parameter
for CH#_scaled.
PV#pos: Measured Variable Decimal [COND:D DISPLAY 0 # •] configuration parameter for
CH#_scaled, presented as 0001 with a decimal in the specified position (for example, 0.01 if
parameter value is 2).
RatedW: On while the speed set point is being ramped to its Rated Speed. Setting this bit while
the controller is in its Ready state selects Rated as the target for subsequent startups. Set-
ting it while the turbine is running causes the controller to ramp the speed up or down to that
target and halts any other active sequence (thus clearing Idle1W, Idle2W, Idle3W, or
StopW). See: Sequencing Operation in Chapter 2.

March 2021 Page 6 of 8 DS3307/D (2.1.0)

Ready and ReadyW: Set to On when the controller is reset to its Ready state, and is cleared
when a startup or shutdown is initiated. Setting ReadyW while the controller is in the Shut-
down state resets it to the Ready state, thus enabling you to initiate a startup.
See: Ready State in Chapter 2.
Remote and RemoteW: On when the remote speed or power set point is selected (depending
on Gen_Enabled). If the local and remote set points are both enabled, setting RemoteW
selects the remote set point and clearing it selects the local set point.
See: Speed and Set Point in Chapter 2.
Reset: Off while the controller is in its Shutdown operating state. The controller must then be
reset to the Ready state (which sets this bit) before the turbine can be restarted.
See: Shutdown State in Chapter 2.
RPM_Display: Selected speed, in rpm. See: Speed and Set Point in Chapter 2.
RS_24V_Fail: On if any discrete input assigned the redundant selector power function clears.
See: Power Supply Failures in Chapter 2.
Run: Set when a ramp to the Rated Speed terminates or is halted after reaching Min_Gov, then
remains On as long as the turbine speed is in the normal operating range.
See: Continuous Operation and Turbine Startup in Chapter 2.
RunW: Setting this bit while the controller is in its Ready state initiates a startup and accelerates
the turbine to the target speed selected by setting the Idle1W, Idle2W, Idle3, or RatedW bit.
If none of those bits is set, the Idle1 target speed is selected by default. This bit is cleared
when the resulting sequence terminates.
See: Turbine Startup and Sequencing Operation in Chapter 2.
Servo#W: Setting or clearing either of these variables (which can only be changed via computer
communications) activates or de-activates any control relays assigned the corresponding
Co0# function. One possible use for such relays is to initiate control responses that can only
be triggered by discrete inputs. See: Control Relays in Chapter 3.
Shutdown: On while the controller is in its Shutdown operating state. The controller must then
be reset to the Ready state (which clears this bit) before the turbine can be restarted.
See: Shutdown State in Chapter 2.
SP_Display: Selected speed set point, in rpm. See: Speed and Set Point in Chapter 2.
Speed_Dev: On when the turbine speed differs from its set point by more than the Deviation
Alarm Threshold. See: Speed Alarms in Chapter 2.
Speed_SPW: This variable reports the current speed set point, in rpm:
• If Computer_RSP, Cascade, Remote and Droop are all Off, the local speed set point is in
use and can be changed by writing to this variable or pressing the Raise and Lower keys.
• If Gen_Enabled is Off and Computer_RSP and Remote are both On, the remote speed set
point is in use and can be changed by writing to this variable.
In either case, the new Speed_SPW value must be between Min_Gov and Max_Gov.
See: Speed and Set Point in Chapter 2.
Speed_Track: On when the remote set point is either not selected or cannot be satisfied due to
a limiting condition or manual operation. The device sending that set point should then track
the actual turbine speed. See: Remote Set Point in Chapter 2.

March 2021 Page 7 of 8 DS3307/D (2.1.0)

SpeedSwitch#: On when or if the speed is or temporarily was beyond the corresponding (speed
switch 1 or 2) alarm threshold. See: Speed Alarms in Chapter 2.
State: The operating state of the controller. See: Operation in Chapter 2.
Stop: On when set when the speed set point is below Minimum Governor and/or is being
ramped. When the Automatic variable is cleared, this boolean will turn on if the speed falls
below but will not turn off if it rises above that threshold.
See: Sequencing Operation in Chapter 2.
StopW: On during a ramped shutdown. Setting this bit while the controller is in its Run or Idle
state initiates that sequence and halts any other active sequence (thus clearing Idle1W,
Idle2W, Idle3W, or RatedW). See: Ramped Stop in Chapter 2.
Tracking: On when this controller is operating as an on-line backup to another.
See: Tracking State in Chapter 2.
Tran_Fail: On when any analog input signal falls outside of its transmitter testing limits (in which
case the corresponding CH#_fail will have a non-zero value), Off when all such signals are
within their acceptable ranges. See: Transmitter Testing in Chapter 3.
User#W: These six variables (3  #  8) are never changed by and do not affect the operation of
the controller, but can be changed and read back. Thus, clients could use them as an OPC
“scratch pad”, perhaps for communication with each other.
Version: Revision of installed control program. See: Program Version in Appendix B.
Write_Inhibit: On when the controller is configured to prevent the listed read/write variables from
being changed via computer communication.
See: Modbus/OPC Configuration in Chapter 3.

March 2021 Page 8 of 8 DS3307/D (2.1.0)

COMPRESSOR CONTROLS CORPORATION

Des Moines, IA, USA
Phone: (515) 270-0857 • Web: www.cccglobal.com
Printed in U.S.A.
 DS3307/MSeries 3++ Speed Controller

#
Speed Controller
Modbus Variables
Product Revision: 1063-005

This data sheet lists this controller’s Modbus coils, discrete inputs, and registers. The Series
3++ Modbus implementation, including descriptions of data types, register scaling, and available
functions, is described in Chapter 2 of UM3300/M. Cross-references in the following descrip-
tions are to the Series 3++ Speed Controller [DS3307/M].
Coils
Address Coil Address Coil Address Coil
00001-2 Servo Relay # 00014 Idle3 00023 Ready
00003-8 User Coils 00015-18 1101 (2) 00024 Cascade
00009-10 01 (1) 00019 Stop 00025 Idle2
00011 Automatic 00020 Idle1 00026 Halt Ramp
00012 Remote 00021 Rated 00027-32 0
00013 Run 00022 ESD
Discrete Inputs
Address Discrete Address Discrete Address Discrete
10001 Automatic 10041 ESD 10057-64 Tran Fail
10002 Remote 10042 Alarm 10065 Power Limit
10003 Ready 10043 Output Fail 10066 Power Fallback
10004 Idle1 10044 Speed Dev 10067-8 Speed Switch #
10005 Run 10045 0 10069 Idle3
10006 Shutdown 10046 Speed Track 10070 Low Battery
10007 Reset 10047 Limit 10071 MOR Active
10008 Cascade 10048 Position Fail 10072 CRZ Stall
10009 Tracking 10049 Low Voltage 10073 FD 24V Fail
10010 OS Test 10050 0 10074 RS 24V Fail
10011-13 MPU # Fail 10051 Aux Board Fail 10075 Write Inhibit
10014 Port 1 Fail 10052 Low Clamp 10076 Computer RSP
10015 Port 2 Fail 10053 High Clamp 10077 Limit Enabled
10016 Tran Fail 10054 Stop 10078 Cascade Enabled
10017-32 DI Condition 10055 Gen Breaker 10079 Gen Enabled
10033-40 CR State 10056 Droop

March 2021 Page 1 of 8 DS3307/M (2.1.0)

 Input Registers
Address Register Scaling (3) Address Register Scaling (3)
30001-08 Channel # 100% 30022 Power CV 100%
30009 RPM Display MCS 30023 Power SP 100%
30010 SP Display MCS 30024 Controller State Integer
30011 OUT Display 100% 30025 Board Temp –50 to 438 °C
30012-14 MPU # MCS 30026 24V Power 29.8 Vdc
30015 OUT1 Readback 100% 30027 15V Power 17.6 Vdc
30016 Last ESD integer 30028 5V Power 6.07 Vdc
30017 Param CRC integer 30029 3.3V Power 4.88 Vdc
30018 OUT 2 100% 30030 1.2V Power 4.88 Vdc
30019 OUT 3 100% 30031 OUT2 Readback 100%
30020 PCV 100% 30032 OUT3 Readback 100%
30021 PCV SP 100% 30033 Loop Counter integer
Holding Registers
Address Register Scaling (3) Address Register Scaling (3)
40001 PCV SP 100% 40004 Power SP 100%
40002 Speed SP Min,MaxGov 40005-37 Input Registers (4) see above
40003 Manual Target 100%
Note 1: Coil 00010 is set to indicate this is a Series 3++ Controller.
Note 2: Although they have coil addresses, bits 00015 through 00018 jointly constitute a read-
only, four-bit integer identifying the controller type.
Note 3: Scaling is the variable value corresponding to port’s configured maximum range. If two
are listed, the first is the variable value when register is zero (0x0000).
Note 4: Each input register can also be read (but not changed) at an address calculated by add-
ing its offset (its address minus 30001) to the address of the first undefined holding register.
CAUTION: The address locations specified for these Input Registers apply only to
this Product Revision. Address locations will shift as holding registers are added.

March 2021 Page 2 of 8 DS3307/M (2.1.0)

 Data Item Descriptions
Unless otherwise noted, speeds are scaled relative to the Maximum Control Speed, with the
port’s configured register maximum (usually 4,000 or 64,000) representing 100 percent of that
MCS. Thus, if the MCS is 8000 rpm, 6000 rpm (75.0 percent) would scale to decimal 3000 or
48000 and 8000 rpm would scale to decimal 4000 or 64000.
1.2V Power, 3.3V Power, 5V Power and 15V Power: Input registers 27 through 30 report the
output voltages of the CPU PCB power converters. See: Internal Conditions in Chapter 2.
24V Power: Input register 26 reports the actual voltage supplied to the CPU PCB by the power
supply assembly. See: Internal Conditions in Chapter 2.
Alarm: Discrete 42 is set when there are unacknowledged alarm conditions.
See: Controller Health in Chapter 2 and Alarms Menu in DS3307/O.
Automatic: Discrete 1 and coil 11 are set when the controller is operating automatically and
cleared when manual is selected. Setting that coil forces the controller into automatic, clear-
ing it forces the controller into manual. See: Manual Operation in Chapter 2.
Aux Board Fail: Discrete 51 is set when the main CPU is unable to communicate with the auxil-
iary/speed board CPU. See: CPU/IO and Auxiliary PCB Faults in Chapter 2.
Board Temp: Input register 25 reports the internal temperature measured by the CPU PCB.
See: Internal Conditions in Chapter 2.
Cascade and Cascade Enabled: Discrete 78 is set when cascade control is enabled. Coil 24
will then be set whenever the cascade speed set point is selected, even if the controller is
not using it (for example, during manual operation). In contrast, discrete 8 is set only when
cascade control is active. Setting coil 24 selects the cascade set point, thus clearing the
Remote coil (12) and discrete (2). Clearing that coil selects the local set point. See: Speed
and Set Point and Cascade Set Point in Chapter 2.
Channel #: Input registers 1 through 8 report the values of the corresponding analog input sig-
nals. Any channel configured as an Offset Zero Input is compensated for a twenty percent
offset. See: Signal Variables in Chapter 3.
Computer RSP: If the Gen Enabled discrete (79) is Off, discrete 76 is set when the Speed SP
holding register (2) reports and changes the remote speed set point. If Gen Enabled is On,
discrete 76 is set when the Power SP holding register (4) reports and changes the remote
power set point. See: Speed and Set Point and Droop Operation in Chapter 2.
Controller State: This is a “debugging” register intended for internal CCC use. It reflects the cur-
rent operating state of the controller.
CR State: Discretes 33 through 40 report the intended states of the control relays — each is set
when the corresponding relay is activated (their offsets are 32 greater than the relay num-
bers). Those corresponding to fault relays reflect only the assigned functions and cannot
indicate hardware faults. See: Control Relays in Chapter 3.
CRZ Stall: Discrete 72 is set when the speed is in a critical zone and the intended valve position
is at its high clamp or under manual control. See: Critical Speed Stall in Chapter 2.
DI Condition: Discretes 17 through 32 reflect the discrete field input states, in ascending order
(17 is DI 1, 32 is DI16). See: Discrete Inputs in Chapter 3.

March 2021 Page 3 of 8 DS3307/M (2.1.0)

Droop: Discrete 56 is set when the controller is regulating a turbine-driven generator’s power
output, rather than its speed and frequency. See: Droop Operation in Chapter 2.
ESD: Setting coil 22 initiates an emergency shutdown (and clears the Idle1/20, Idle2/25,
Idle3/14, Rated/21, and Stop/19 coils). Initiating such a shutdown from the Front Panel or via
discrete field inputs also sets this coil. It remains set until the controller is reset to the Ready
state by asserting the Ready coil (23), pressing the Reset key, or asserting a Reset discrete
field input. See: Emergency Shutdown in Chapter 2.
FD 24V Fail: Discrete 73 is set if any discrete field input assigned the field device power func-
tion clears. See: Power Supply Failures in Chapter 2.
Gen Breaker: Discrete 55 is set when a generator control application’s generator breaker input
is asserted. See: Synchronous Generator in Chapter 2.
Gen Enabled: Discrete 79 is set when generator control is enabled.
See: Synchronous Generator in Chapter 2.
Halt Ramp: Setting coil 26 interrupts any active sequence and clears the associated Idle1/20,
Idle2/25, Idle3/14, Rated/21, or Stop/19 coil. See: Sequencing Operation in Chapter 2.
High Clamp and Low Clamp: Discrete 52 is set when the intended valve position is at or below
its configured minimum value, while discrete 53 is set when it is at or above its upper limit.
See: Control Element Position in Chapter 2.
Idle1: Discrete 4 is set when the speed set point is greater than or equal to the Idle1 Speed and
less than the Idle2 Speed (or Minimum Governor if the Idle2 Speed is zero).
Setting coil 20 while the controller is in its Ready state selects the Idle1 Speed as the target
for any subsequent startup sequence. Setting it while the turbine is running causes the con-
troller to ramp the speed up or down to that target speed. Initiating any of those sequences
from the Front Panel or via discrete field inputs also sets coil 20. In all cases, it is cleared
when the resulting sequence terminates. Setting coil 20 also clears the Idle2/25, Idle3/14,
Rated/21, and Stop/19 coils. It can not be set while the ESD coil (22) is set.
See: Idle State in Chapter 2.
Idle2: Discrete 41 is set when the speed set point is greater than or equal to the Idle2 Speed
and less than the Idle3 Speed (or Minimum Governor if the Idle3 Speed is zero).
Setting coil 25 while the controller is in its Ready state selects the Idle2 Speed as the target
for any subsequent startup sequence. Setting it while the turbine is running causes the con-
troller to ramp the speed up or down to that target speed. Initiating any of those sequences
from the Front Panel or via discrete field inputs also sets coil 25. In all cases, it is cleared
when the resulting sequence terminates. Setting coil 25 also clears the Idle1/20, Idle3/14,
Rated/21, and Stop/19 coils. It can not be set while the ESD coil (22) is set.
See: Idle State in Chapter 2.
Idle3: Discrete 69 is set when the speed set point is greater than or equal to the Idle3 Speed
and less than Minimum Governor.
Setting coil 14 while the controller is in its Ready state selects the Idle2 Speed as the target
for any subsequent startup sequence. Setting it while the turbine is running causes the con-
troller to ramp the speed up or down to that target speed. Initiating any of those sequences
from the Front Panel or via discrete field inputs also sets coil 14. In all cases, it is cleared
when the resulting sequence terminates. Setting coil 14 also clears the Idle1/20, Idle2/25,
Rated/21, and Stop/19 coils. It can not be set while the ESD coil (22) is set.
See: Idle State in Chapter 2.

March 2021 Page 4 of 8 DS3307/M (2.1.0)

Last ESD: Input register 16 reports the cause of the most recent shutdown:
01: Overspeed trip 32: Shutdown occurred while tracking
02: Front-panel operating mode request 34: Auxiliary/Speed Board failure
04: Failure of all enabled MPUs 64 to 79: ESD field DI number + 63
08: Failsafe shutdown during startup 128: Breaker shutdown
16: Watchdog shutdown (fault) else: unset or corrupted
See: Shutdown State in Chapter 2.
Limit: Discrete 47 is set when the limiting control loop is reducing the steam flow, or the speed
control response is at its upper or lower demand clamp (extraction applications).
See: Limiting Control and Control Element Position in Chapter 2.
Limit Enabled: Discrete 77 is set when the limiting control loop is enabled.
See: Limiting Control in Chapter 2.
Loop Counter: Input register 33 shows the control loop counter which continuously counts up to
255 and recycles to zero, while the controller is active. This variable indicates controller
activity and is primarily used for testing purposes.
Low Battery: Discrete 70 is set when low battery voltage is detected on the RTC/RAM chip (Rev
B and higher CPU boards only). See: Battery Failure in Chapter 2.
Low Voltage: Discrete 49 is set when any internally-monitored CPU PCB component power
voltage is below its alarm level. See: Power Supply Failures in Chapter 2.
Manual Target: Holding register 3 reports the intended valve position (percent open). If the
Automatic coil (11) is cleared, you can directly control the actuator output signal by writing
the desired valve position to this register. See: Manual Operation in Chapter 2.
MOR Active: Discrete 71 is set when the manually specified valve position is declining because
the speed is above maximum governor. See: Manual Operation in Chapter 2.
MPU #: Input registers 12 through 14 report the speeds calculated from the corresponding
speed input signals (MPU 1 through 3) as a percentage of the maximum control speed.
See: Speed Input Signals in Chapter 2.
MPU # Fail: Discretes 11 through 13 are set when the corresponding magnetic pickup signals
are less than the Control Threshold or outside the deviation window (three-MPU installations
only). The offset of each discrete is calculated by adding 10 to the input number (10011 is
for MPU 1 and 10013 is for MPU 3). See: Speed Input Failures in Chapter 2.
OS Test: Discrete 10 is set whenever the Overspeed Trip Test is enabled.
See: Overspeed Trip Test in Chapter 8.
OUT Display: Input register 11 reports the displayed intended valve position (percent open).
See: Control Element Position and Manual Operation in Chapter 2.
OUT1 Readback: Input register 15 usually reports the actual value of the high-current output
(OUT1). If the internal positioning loop is enabled, however, it reports the valve position
measured by the LVDT input.
See: Control Element Position and Analog Output Signals in Chapter 2.
Output Fail: Discrete 43 is set if the deviation of OUT1 Readback from Manual Target exceeds
5.0 percent for longer than the Output Failure Delay. See: Output Loopback Test in Chapter
3.

March 2021 Page 5 of 8 DS3307/M (2.1.0)

OUT 2, OUT2 Readback, OUT 3 and OUT3 Readback: Input registers 31 and 32 report the
intended values of the standard analog output signals, while registers 24 and 25 report their
actual values. See: Analog Output Signals in Chapter 2.
Param CRC: Regardless of the configured scaling, input register 17 reports the 16-bit cyclic
redundancy checksum for the controller’s current set of configuration and tuning parame-
ters. See: Parameter Checksum in Appendix B.
PCV and PCV SP: Input registers 20 and 21 report the performance control variable and its set
point or control threshold:
• If Limit Enabled is On, holding register 1 reports and can change its limiting control
threshold. See: Limiting Control in Chapter 2.
• If Cascade Enabled is On, holding register 1 reports and can change its set point. The
speed control loop can then be forced to use its cascade set point by setting the Cascade
coil (24). See: Cascade Set Point in Chapter 2.
Port 1 Fail and Port 2 Fail: Discrete 14 is set if the controller fails to receive Port 1 data it has
been configured to expect, input 15 is never set (Speed Controllers do not use Port 2).
See: Serial Communication Errors in Chapter 2.
Position Fail: Discrete 48 is set if the valve positioning test deviation exceeds 5.0 percent for
more than the Output Failure Delay. See: Output and Valve Position Failures in Chapter 2.
Power CV: Input register 22 reports the generated power, scaled as a percentage of the config-
ured maximum power. See: Droop Operation in Chapter 2.
Power Fallback: Discrete 66 is set when the generated electrical power input fails, in which
case that measurement is estimated from the intended valve position.
See: Droop Operation in Chapter 2.
Power Limit: Discrete 65 is set if the generated power (measured or characterized) reaches its
configured maximum set point. See: Droop Operation in Chapter 2.
Power SP: Input register 23 reports the generated power set point, scaled as a percentage
of the configured maximum power. If the Cascade discrete is off and the Computer RSP and
Remote discretes have the same value, that set point can be changed via holding register 4.
See: Droop Operation in Chapter 2.
Rated: Setting coil 21 while the controller is in its Ready state selects the Rated Speed as the
target for any subsequent startup sequence. Setting it while the turbine is running at a speed
below Minimum Governor causes the controller to ramp the speed up to that target. Initiating
either sequence from the Front Panel or via discrete field inputs also sets coil 21, which is
then cleared when the sequence terminates. Setting coil 21 also clears the Idle1/20,
Idle2/25, Idle3/14, and Stop/19 coils. It can not be set while the ESD coil (22) is set.
See: Sequencing Operation in Chapter 2.
Ready: Discrete 3 and coil 23 are set when the controller is reset to its Ready state, and is
cleared when a startup or shutdown is initiated. Setting that coil while the controller is in the
Shutdown state resets it to the Ready state, thus enabling you to initiate a startup. Setting
the coil while not in the Shutdown state clears all alarms. See: Ready State in Chapter 2.

March 2021 Page 6 of 8 DS3307/M (2.1.0)

Remote: Coil 12 is set whenever the remote speed or power set point is selected, even if the
controller is not using it (for example, if it is being manually operated). In contrast, discrete 2
is set only if the controller is actually using the remote set point. Clearing this coil selects the
local set point, setting it selects the remote set point (and clears Cascade coil 24 and dis-
crete 8, if set). If the Automatic discrete (1) is set and the Remote and Cascade discretes (2
and 8) are cleared, the controller is using its local speed or power set point.
See: Speed and Set Point in Chapter 2.
Reset: Discrete 7 is set whenever the controller is reset and is cleared thirty seconds later.
See: CPU Reset Count in Appendix B.
RPM Display: Input register 9 reports the selected control speed displayed by the front-panel
RPM readout, as a percentage of the MCS. See: Speed and Set Point in Chapter 2.
RS 24V Fail: Discrete 74 is set if any discrete field input assigned the redundant selector power
function clears. See: Power Supply Failures in Chapter 2.
Run: Discrete 5 is set when a ramp to the Rated Speed terminates or is halted after the speed
reaches Minimum Governor, then remains set as long as the speed is in the normal operat-
ing range.
Setting coil 13 while the controller is in its Ready state initiates a startup and accelerates the
turbine to a target speed selected by setting the Idle1/20, Idle2/25, Idle3/14, or Rated/21 coil
(if none of those coils is set, Idle1 is selected by default). It is cleared when the resulting
sequence terminates.
See: Continuous Operation and Turbine Startup in Chapter 2.
Servo Relay #: Coils 1 and 2, which can only be set and cleared by a Modbus host, activate and
de-activate any control relays assigned the corresponding Co0# function. One possible use
for such relays is to initiate control responses that can only be triggered by discrete field
inputs. See: Control Relays in Chapter 3.
Shutdown: Discrete 6 is set at the conclusion of any ramped or emergency shutdown, regard-
less of how it is initiated. The controller must then be reset to the Ready state (which clears
this discrete) before the turbine can be restarted. See: Shutdown State in Chapter 2.
Speed Dev: Discrete 44 is set when the turbine speed differs from its set point by more than the
Deviation Alarm Threshold. See: Speed Alarms in Chapter 2.
Speed SP and SP Display: Input register 10 reports the selected speed set point, as a percent-
age of the MCS. When the Cascade discrete is off, either the local or remote set point can
be changed by writing to holding register 2:
• If the Computer RSP discrete (76) is on, the remote set point can be changed only by
writing to holding register 2 while the Remote discrete (2) is also on. If the Run state is
selected, the speed control loop can be forced to use that set point by setting the Remote
coil (12).
• If the Computer RSP discrete (76) is off, writing to holding register 2 while the Remote
discrete (2) is also off is only one of the ways the local set point can be changed. If the
Run state is selected, the speed control loop can be forced to use that set point by clear-
ing both the Remote and Cascade coils (2 and 24).
In either case, the set point value is a linear function of the normal operating range. Zero is
equal to Minimum Governor, while 100.0 percent equals Maximum Governor.
See: Speed and Set Point in Chapter 2.

March 2021 Page 7 of 8 DS3307/M (2.1.0)

Speed Switch #: Discrete 67 or 68 is set if the speed is or temporarily was beyond the speed
switch 1 or 2 alarm threshold. See: Speed Alarms in Chapter 2.
Speed Track: Discrete 46 is set when the remote set point is either not selected or cannot be
satisfied due to a limiting condition or manual operation. The device sending that set point
should then track the actual turbine speed. See: Remote Set Point in Chapter 2.
Stop: Discrete 54 is set when the speed set point is below Minimum Governor and/or is being
ramped. When the Automatic discrete is cleared, this discrete will set if the speed falls below
but will not clear if it rises above that threshold.
Setting coil 19 while the controller is in its Run or Idle state initiates a ramped shutdown,
initiating that sequence from the Front Panel or via discrete field inputs also sets this coil. In
all cases, it is cleared at the end of the resulting sequence. Setting coil 19 also clears the
Idle1/20, Idle2/25, Idle3/14, and Rated/21 coils. It can not be set while the ESD coil (22) is
set.
See: Sequencing Operation and Ramped Stop in Chapter 2.
Tracking: Discrete 9 is set only when the controller is operating as a backup to another Speed
Controller. See: Tracking State in Chapter 2.
Tran Fail: Discrete 7 is set when any analog input signal falls outside of its transmitter testing
limits. See: Transmitter Failures in Chapter 2.
Tran Fail #: Discretes 57 through 64 indicate when their associated analog input signals fall out-
side of their transmitter testing limits. See: Transmitter Failures in Chapter 2.
User Coils: Coils 3 through 8 are never changed by and do not affect the operation of the
controller, but can be changed and read back. Thus, hosts can use them as a Modbus
“scratch pad”, perhaps for communication with each other.
Write Inhibit: Discrete 75 is set when hosts cannot change coils and holding registers.
See: Modbus/OPC Configuration in Chapter 3.

March 2021 Page 8 of 8 DS3307/M (2.1.0)

COMPRESSOR CONTROLS CORPORATION

Des Moines, IA, USA
Phone: (515) 270-0857 • Web: www.cccglobal.com
Printed in U.S.A.
DS3307/O Series 3++ Speed Controller

#
Speed Controller
Operator Interface
Product Revision: 1063-005

Overview This data sheet describes the Series 3++ Speed Controller’s Control
Loop Readouts (see page 2), Control Keys and LEDs (see page 3),
and Status LEDs and Screen (see page 6).

3620 RPM
Control Loop

SP
3600 83.1 OUT
Readouts and
Buttons
CASC LIMIT POWER

Speed Controller

Control
Fault Spd/Remote Controller Status
Alarm Screen, LEDs,
and Buttons
ACK MENU SCROLL

Remote
AUTO MAN ESD
Local
RESET
GenPwr

Cascade

Tracking

Limit
OP
MODE
SP
MODE  Control Keys
and LEDs
Run

Idle

Stop
TEST ENTER 
A #

Cross-references are to the Series 3++ Speed Controller [UM3307],

which tells how to operate and configure these controllers. In pdf
versions of this document, each element in the above illustration is
linked to the corresponding description.

March 2021 Page 1 of 16 DS3307/O (2.1.0)

 Control Loop The upper section of this controller’s front panel includes:

Readouts • Speed (RPM), Set Point (SP), and Output (OUT) readouts that
normally report the status of the speed control loop, and
• CASCade, LIMIT, and POWER buttons that can be pressed to
temporarily display the value and set point for the corresponding
control loop.
These readouts can be brightened or dimmed from the Testing and
Options Menu (see page 15).
The five-digit RPM readout usually displays the turbine’s rotational
RPM speed in revolutions per minute. The RPM will display "xxxx" when
the MPU is disabled.

The five-digit SP readout usually displays the set point for the speed
SP control loop, also in rpm.

The three-digit OUT readout displays the intended valve position

OUT (IVP), in percent of span. If output reverse is enabled, this will be the
complement of the actuator control signal (ACS = 1 – IVP). In most
applications, the IVP equals the clamped speed control response. If
extraction control is enabled, it equals the clamped V1 flow rate.
If the cascade control loop is enabled, the RPM and SP readouts will
CASC temporarily display that loop’s process variable and set point when
the CASC button is held down.
If the limiting control loop is enabled, the RPM and SP readouts will
LIMIT temporarily display that loop’s process variable and set point when
the LIMIT button is held down.
If generator control is enabled, the RPM and SP readouts will tem-
POWER porarily display the generated electrical power and its set point when
the POWER button is held down.
Pressing the POWER button and the SCROLL button at the same
time will instantaneously change the frequency of the controller’s
beep sound to its highest value (silent).

March 2021 Page 2 of 16 DS3307/O (2.1.0)

 Control Keys The lower section of the front panel includes twelve control LEDs,
eight control keys, and the front-panel TEST key (see Testing and
and LEDs Options Menu on page 15).
The LEDs in the AUTO and MAN keys indicate whether the control-
AUTO MAN
ler is operating automatically or manually:
• The green LED in the AUTO key indicates automatic operation.
• The yellow LED in the MAN key indicates manual operation. It will
flash if a remote manual discrete input is asserted, to indicate the
output is being remotely controlled via analog input CH2.
If Manual Operation is enabled, pressing either key while its LED is
off will toggle the controller to that mode of operation and light that
indicator. Automatic or manual operation can also be selected by
asserting discrete inputs or via serial communications.
The Raise and Lower keys vary the actuator control signal, local
 speed set point, or performance (cascade or limiting) set point:
• If the Manual key LED is lit, pressing one of these keys changes
the intended valve position.
 • If the Auto key and Local LEDs are lit, pressing one of these keys
changes the local speed set point. If droop control is active, the
power set point is changed proportionally.
• If the Auto key and Cascade LEDs are lit and the Control Menu
is displaying the performance control variable and its set point,
pressing one of these keys changes that set point.
• If the Control Menu is displaying the limiting control variable and
set point, pressing one of these keys changes that set point.
• Pressing either key during a set point ramp aborts that ramp with
the local set point selected at its last ramped value.
When raising the control response or performance set point/limit,
momentarily pressing the Raise key increments that signal by 0.1
percent. Holding it down increases that signal in steadily larger
steps (it takes about 20 seconds to change either signal by 100 per-
cent). The Lower key decreases those signals in a similar fashion.
When raising the local speed set point, momentarily pressing the
Raise key increases that signal by 1 rpm. Holding it down increases
that set point at the Local Set Point Ramp Rate [COND:S SP 1].
Pressing the Lower key lowers this set point in a similar fashion.
The green GenPwr (generating power) LED is lit when generator
GenPwr
droop control is active, or flashes to indicate isochronous control of
the generator speed and electrical frequency.
It will flash mostly Off when the controller is in automatic control and
the breaker is closed, but the controller is not in the Run State.

Tracking When redundant controllers have been installed, the green Tracking
LED of the active controller is off and that of its backup is lit.

March 2021 Page 3 of 16 DS3307/O (2.1.0)

 The yellow Limit LED is lit when the limiting loop is controlling the
Limit
steam flow, or the speed control response is at its upper or lower
clamp (extraction applications).
Pressing the ENTER key initiates a Set Point Mode change or
ENTER
selects or confirms an Operating Mode change.

Set Point Mode Either the green Remote, yellow Local, or yellow Cascade LED is
always lit to indicate the source of the speed (GenPwr LED off or
flashing) or electrical power (GenPwr LED on) set point:
• The Remote LED is lit when the remote set point is selected,
Remote
which can be varied by an analog input, companion controller, or
a Modbus host. If that source is selected, this LED flashes during
ramps to the Rated Speed or if the controller is in manual.
• The Local LED is lit when the local set point is selected, which
Local
can be varied by the Raise and Lower keys, discrete inputs, or a
Modbus host (provided the Auto and Run LEDs are lit).
• The Cascade LED is lit when the cascade set point is selected,
Cascade
which is varied by the internal performance control loop. If that
source is selected, this LED flashes during ramps to the Rated
Speed, if the speed is below Minimum Governor, or if the control-
ler is in manual.
To change the selected set point source, press the SP MODE key to
SP blank the second and fourth lines and display a prompt in the third
MODE
line of the status screen:
1. Press the SP MODE key repeatedly until the prompt for the
desired set point source appears (each prompt will appear only
if that set point source is enabled):

SP Remote
MODE Select?

SP Local
MODE Select?

SP Cascade
MODE Select?
2. Press the ENTER key to select the displayed set point source
and light the corresponding LED.
To abort this procedure, press either the MENU or SCROLL button
or press the SP MODE key repeatedly until the previously displayed
menu system screen reappears.

March 2021 Page 4 of 16 DS3307/O (2.1.0)

 The set point source can also be changed by asserting discrete
inputs or via computer communications.

If generator control is enabled, the remote or cascade set point can

Note: be selected only when droop control is active.

Operating Mode The red LED in the upper left corner of the ESD key is lit following
an emergency shutdown. The controller will then operate in its Shut-
down state, the governor valve will be fully closed, manual operation
cannot be selected, and the turbine cannot be restarted. Pressing
the ESD key will clear all alarms, advance the controller to its Ready
state, and light the red Stop LED.
An online backup controller will light its ESD LED if its active peer
ESD
does or if any of its own ESD inputs are asserted.
The red Stop LED is lit when a turbine startup can be initiated. The
governor valve will remain fully closed unless manual operation is
Stop initiated. This LED flashes when a ramped stop is in progress.

Run The green Run LED is lit when the speed set point is at or above
Minimum Governor and is not being ramped. It flashes during any
sequence that will end at the Rated Speed.
The yellow Idle LED is lit when the speed set point is below Mini-
Idle
mum Governor. It flashes during any sequence that will end at one
of the idle speeds.
Changing the operating mode initiates a startup or shutdown, idles a
OP running turbine, or brings an idling turbine on-line (see Sequencing
MODE
Operation in Chapter 2). Pressing the OP MODE key blanks the
second and displays a prompt in the bottom two lines of the status
screen:
1. Press the OP MODE key repeatedly until the desired mode’s
prompt is displayed in the status screen. For example:

OP Rated 5000
MODE Select?
The number following the idle or rated mode prompt is the value
of the corresponding target speed (5000 in the above example).
2. Press the ENTER key once to select that mode. You will then be
prompted to verify the specified change:
Rated 5000
ENTER
Confirm?
3. Pressing ENTER a second time initiates the change, pressing OP
MODE aborts it.

March 2021 Page 5 of 16 DS3307/O (2.1.0)

 The controller can be set up to pause before initiating a stop or slow
to idle sequence. During this pause, you can cancel that change by
initiating manual operation or selecting the Rated mode.
Automatic sequences can also be initiated by asserting discrete
inputs or via computer communications.

Status LEDs The center section of the front panel includes:

and Screen • the controller Fault and Alarm LEDs,

• a ten-character by four-line Status Screen, and
• three buttons for operating that screen’s menu system.
The red Fault LED is lit if:
Fault • the engineering panel is unable to communicate with the CPU, in
which case the status screen displays “No Comms with Main
CPU”, and all other display elements turn off; or
• the CPU is unable to communicate with the Auxiliary PCB, in
which case the other LEDs, control loop readouts, and status
screen will continue to operate.
In either case, an alternate means of controlling the turbine should
be immediately activated.

If the Fault LED lights or any Fault relay de-activates, the analog
Caution: output signal should be immediately disconnected from its control
element (the connected circuits often include relays that do so).

The yellow Alarm LED is lit whenever one or more alarm conditions
exist. Additional information can then be obtained via the Alarms
Alarm Menu (see page 12). When a new alarm condition is detected, this
LED flashes and the alarms menu is automatically displayed.
Acknowledging and correcting all active alarms turns this LED off.

Control Each line of the status screen can display up to ten letters, digits, or
other symbols:
13:52:11 • The top line always identifies the currently-selected menu. Press-
12/25/06 ing the MENU button cycles through the first screens of the avail-
able menus, whose second lines will be blank while the bottom
two display the current 24-hour time (hour/minute/seconds) and
date (month/day/year).
• Pressing the SCROLL button cycles through the selected menu’s
MENU available screens.
The contrast of the status screen can be adjusted from the Testing
and Options Menu (see page 15).
SCROLL
Holding down the SCROLL button and pressing the Raise or Lower
key will change the frequency of the controller’s beep sound.

March 2021 Page 6 of 16 DS3307/O (2.1.0)

 Pressing the SCROLL button and the POWER button at the same
time will instantaneously change the frequency of the controller’s
beep sound to its highest value (silent).

Control Menu Selecting the Control menu and pressing SCROLL will display the
controller’s Operating State (see below):

Control
Spd/Local

Pressing SCROLL a second time displays “Limit” or “Cascade” on

the second line (if either loop is enabled), followed by that loop’s
process variable and set point on the third and fourth lines:

Control Control
Limit Cascade
PV: ##.# or PV: ##.#
SP: ##.# SP: ##.#

Pressing SCROLL again displays “Power” on the second line (if

generator control is enabled), followed by the generated power and
its set point on the third and fourth lines:

Control
Power
PV: ##.#
SP: ##.#

Operating State When the turbine is running under automatic control, the displayed
states depend on whether or not Generator Control is enabled.
If Generator Control is not enabled, the operating state indicates
which speed set point is being used:
• Spd/Local indicates the speed control loop is regulating turbine
speed using a local set point, or that the turbine is idling or being
ramped on-line.
• Spd/Remote indicates that loop is using a remote set point.
• Spd/Casc indicates the cascade control loop is calculating the
speed set point from the performance control variable deviation.
If Generator Control is enabled, the state indicates the selected
mode (droop or isochronous) and whether the generator is on-line:
• Spd/Droop indicates the rotational speed is being controlled
because the generator is off-line. The controller will switch to its
droop mode if the generator breaker is closed.

March 2021 Page 7 of 16 DS3307/O (2.1.0)

 • Spd/Isoch indicates the generator is off-line but the controller will
continue to control its speed (isochronous control) even if the
generator breaker is closed.
• Isoch means the generator is under isochronous control.
• Droop means the generator is under droop control.
If manual operation or redundant controller tracking is active, the
operating state displays as:
• Manual indicates the intended valve position is being controlled
by the Raise and Lower keys or OutUP and OutDN discrete
inputs, rather than by the PID algorithm.
• RemtManual indicates the intended valve position is being con-
trolled by analog input CH2 because a discrete input assigned
the Remote Manual function is asserted.
• Tracking indicates this redundant controller is duplicating the con-
trol response, set point mode, and operating state of another
Speed Controller via the Port 1 serial link, and will assume control
of the turbine if that other controller fails.
If the turbine is shut down, the displayed state indicates why:
• Overspd SD indicates the turbine was shut down because it
exceeded the Electronic Overspeed Trip speed.
• MPULoss SD indicates the turbine was shut down because all of
its speed inputs failed.
• Breaker SD indicates the turbine was shut down when the gener-
ator breaker unexpectedly opened.
• DGI SD ## means the shutdown was initiated by Stop or ESD
input number ##.
• OperatorSD indicates the shutdown was initiated by selecting the
Shutdown or Stop Operating Mode (see page 5) or setting the
Modbus Stop or ESD coil.
• FailsafeSD means a start-up aborted when the turbine failed to
reach Minimum Control Speed before the Failsafe Timer elapsed.
• WatchdogSD means a power loss or controller failure caused a
hard reset of the CPU, thus tripping the turbine.
• AuxBoardSD indicates the turbine was shut down because the
Auxiliary PCB failed.
• TrackingSD indicates the turbine was shut down by this control-
ler’s active peer.

March 2021 Page 8 of 16 DS3307/O (2.1.0)

 You can also identify the causes of the last eight shutdowns by
scrolling the SD Log Menu (see page 14).
In any case, you must reset the controller before you can restart the
turbine. Once you have done so, the operating state will indicate
whether or not there are any unsatisfied start permissives:
• NotRdyPerm indicates turbine operation cannot be resumed
because of an unsatisfied Permissive input.
• NotRdy ESD indicates turbine operation cannot be resumed
because of an unsatisfied Shutdown input.
• ReadyToRun indicates the turbine is stopped but can be started.

March 2021 Page 9 of 16 DS3307/O (2.1.0)

 In/Out Menu Selecting the In/Out menu and pressing SCROLL displays the
values of the enabled speed inputs, in rpm:

In/Out
Spd1 4969
Spd2 5001
SPD3 4983

The label for the selected input is displayed in all uppercase letters
(SPD3 above), the labels for the others are capitalized (Spd#).
Pressing SCROLL a second and third time displays the states of the
digital inputs and outputs:

In/Out In/Out
Digital In DigitalOut
Î:1__4___8 then Î:1_3___7_
¨:9____E_G

Each digit or letter (A for input 10, G for 16) appears if that circuit is
asserted or energized, otherwise it is replaced by an underscore.
The digits for the fault relays (CR1 and possibly CR2) will appear
unless they are de-activated by CR1’s assigned function. In the
above examples, inputs 1, 4, 8, 9, 14 (E), and 16 (G) are asserted,
and only CR1, CR3 and CR7 should be activated.
If the remote set point is enabled, pressing SCROLL again displays
the remotely-specified speed or droop set point (in rpm):

In/Out
RmSP= ####

The next two presses of the SCROLL button display the intended
and read-back values of the analog outputs:

In/Out In/Out
Out1 =##.# RdBk1=##.#
Out2 =##.# then RdBk2=##.#
Out3 =##.# RdBk3=##.#

If reverse action is enabled for an output, the displayed value will be

the complement of the variable it represents.

March 2021 Page 10 of 16 DS3307/O (2.1.0)

 Analog In Menu Selecting the Analog In menu and pressing SCROLL displays the
scaled value of one analog input on the fourth line, below its config-
urable eight-character name on the third line:

Analog In Analog In

1:V1 Press or 1:V1 Press

250. psig 0. Fail

If an input’s unscaled value is within its acceptable range (see

Transmitter Testing in Chapter 3), a user-defined engineering units
label will appear after its scaled value (as shown to the left above).
If not, the word “Fail” will be displayed, the Alarm LED will be lit, and
the Alarms Menu (see page 12) would indicate at least one “Tran#
Fail” condition.
Pressing SCROLL repeatedly will cycle through the screens for all of
the enabled Measured Variables (see Chapter 3).

Diagnostic Menu Selecting the Diagnostic menu and pressing the SCROLL button
displays the checksum (any hexadecimal number), and the com-
puter and controller ID numbers:

Diagnostic
CS=7128
CompID# 05
CtrlID# 4

The next two presses of the SCROLL button display the actual
CPU/IO PCB component power voltages:

Diagnostic Diagnostic
Power: AB 5.0V = 5.0
24V = 24.0 then 3.3V = 3.3
15V = 15.0 1.2V = 1.2

The next press of the SCROLL button displays the controller’s inter-
nal temperature:

Diagnostic
Board Temp

050. degC

March 2021 Page 11 of 16 DS3307/O (2.1.0)

 Alarms Menu Alarms are identified and acknowledged via this menu, which is
essentially a list of up to eight active alarm conditions. Each screen
identifies one active alarm, and pressing the SCROLL button dis-
plays the next, in reverse chronological order:

Alarms
Com1 Error

The Alarm LED is lit if the displayed alarm has been acknowledged
or flashes if it has not. If flashing, that alarm can be acknowledged
Alarm by pressing the ACK button. It is then removed from the list only if it
has been corrected, otherwise the LED quits flashing but the alarm
ACK remains on the list until it is corrected. Acknowledging and correct-
ing all active alarms turns the LED off.
When a new alarm is posted, this menu is automatically selected
and scrolled to display it. Resetting the controller to its Ready state
clears the alarm list. Setting the Ready Modbus coil (00023) while
the controller is not in the Shutdown State will also clear all alarms.

Message Condition Reference

Aux. Board CPU cannot communicate with Auxiliary PCB page 47
Com1 Error control-level Port1 communication error page 50
CRZ Stall speed remained within a critical zone too long page 39
FD24V Fail field device power supply failure page 48
HiActuator control response at high clamp page 26
IdleEnable idle ramp initiated while in Run state page 37
LoActuator control response at low clamp page 26
low battery voltage detected on the RTC/RAM chip (Rev
LowBattery page 48
B and higher CPU boards only).
Max Load droop set point at its high clamp page 34
MOR active manual override is limiting manual operation page 44
MPU# Fail failure of indicated (#) speed input page 49
MW Fallbck fallback to valve droop—all power inputs failed page 34
OutputFail unacceptable deviation page 50
PosFeedbck unacceptable deviation of position feedback signal page 50
Pwr Supply internal power supply failure page 48
RS24V Fail redundant control selector power supply failure page 48
SpdSwitch# speed is or was beyond speed switch # threshold page 30
Speed Dev excessive turbine speed deviation page 30
Tran# Fail analog input # is beyond its transmitter testing range page 49
OSP_Action speed above Overspeed Prevention threshold page 115

March 2021 Page 12 of 16 DS3307/O (2.1.0)

 Overspeed Menu The Overspeed Menu is available only if the Overspeed Trip Test
(see Chapter 8) is enabled. Selecting it and pressing the SCROLL
button will then display the following associated variables:

Overspeed
EOST 8000
MOST 9000
MaxN 9000

EOST the speed at which the controller will initiate an

emergency shutdown of the turbine.
MOST the speed at which the test ended or a shutdown
was initiated by a discrete input.
MaxN the highest speed detected since the engineering
panel Maximum Recorded Speed [COND:S SP 3]
procedure was last used to reset it.
Pressing SCROLL again displays the prompt for initiating the test,
which is done by holding the ENTER key down:

Overspeed Overspeed
Test TestActive


While holding ENTER down, you can raise the speed set point
above maximum governor by pressing the Raise key:
• If the speed rises above Maximum Governor, this prompt will
change to AboveMaxGv.
• If the speed rises above the Electronic Overspeed Trip threshold,
this prompt will change to Above EOST, in which case releasing
the ENTER key would trigger an emergency shutdown.
Overspeed Overspeed
AboveMaxGv Above EOST
or

Pressing SCROLL a third time displays the trip and throttle valve
closing time in milliseconds (5000 maximum):

Overspeed
TTValv####

March 2021 Page 13 of 16 DS3307/O (2.1.0)

 SD Log Menu Selecting the SD Log menu and pressing SCROLL once displays
the cause of the most recent turbine shutdown and the time and
date at which it occurred (as discussed on page 8):

SD Log 1
WatchDogSD
13:52:11
12/25/06

Each subsequent press of the SCROLL key displays the same infor-
mation for the next older of the last eight shutdowns:

SD Log 8
OperatorSD
19:43:52
03/02/06

If this controller has not shut the turbine down eight times, the older
log entries will obviously be invalid. Unless the random initial values
of the corresponding memory locations happened to correspond to
one of the eight possible shutdown codes, the second lines of those
log entries would display “Undefined” and the third and fourth lines
would display meaningless, possibly-invalid times and dates (for
example, the following entry indicates 73 minutes and 62 seconds
after 7 PM on the 43rd day of the 17th month of 2025):

SD Log 8
Undefined
19:73:62
17/43/25

Undefined might also appear because a stored shutdown code has

been corrupted.

March 2021 Page 14 of 16 DS3307/O (2.1.0)

 Testing and Holding the TEST key down invokes the Display Testing and
Options Menu Options menu:

Display
Testing &
Options
Ver. #.##

where the # characters represent the digits of the installed version of

TEST
the front-panel firmware. You must continue to hold the TEST key
down while scrolling through and using any of the following tests.
The first press of the SCROLL button invokes the procedure for
adjusting the contrast of the status screen’s liquid crystal display:

LCD
Contrast
Adjustment
Use ¨Î

Unless this contrast is already set to its highest (or lowest) level, it
will then be slightly increased (or decreased) each time you press
the Raise (or Lower) key.
The second press of the SCROLL button invokes a display from
which you can brighten or dim the control loop readouts:

LED
Brightness
Adjustment
Use ¨Î

Unless the readouts are already brightened (or dimmed), pressing

the Raise (or Lower) key will then make them brighter (or dimmer).
The third press of the SCROLL button initiates the LED Test, which
displays the following message and turns on every numeric readout
segment and LED on the Front and Engineering Panels:

LED Test

March 2021 Page 15 of 16 DS3307/O (2.1.0)

March 2021 Page 16 of 16 DS3307/O (2.1.0)

COMPRESSOR CONTROLS CORPORATION

Des Moines, IA, USA
Phone: (515) 270-0857 • Web: www.cccglobal.com
Printed in U.S.A.
 DS3307/V. Series 3++ Speed Controller

#
Speed Controller
Revision History
This data sheet describes the changes in each standard release of this controller. Cross-
references are to the Series 3++ Speed Controller [UM3307].

1061-001 CRC: 2B0B, ID Code: 1; Released: July 2007

In addition to supporting the new Series 3++ hardware platform, the
initial release of this application differed from revision 1056-004 of
the Series 3 Plus Speed Controller as described below.
Alarms The "Aux Board" alarm was added, which is triggered (along with
any Fail relays) if the CPU is unable to communicate with the Speed
Board for four consecutive scans (160 ms). A communication failure
lasting eight scans will trigger a shutdown.
Application Function The option to regulate rotational speed cubed was eliminated (the
Application Function [MODE:S fA] was removed).
Cascade/Limiting The option of connecting a redundant performance control variable
Control signal to analog input CH5 was eliminated (the Alternate PCV Input
[MODE:C SS 3] and PCV Spread Alarm Threshold [COND:C Alarm
3] parameters and "PV Spread" alarm were removed).
The PV and SP readouts for this loop now use the CH1 measured
variable scaling (COND:D DISPLAY 1 LOW, HIGH, and •).
The PCV Display scaling parameters [COND:C DISPLAY 1 LOW,
HIGH, and •] were removed.
Generator Control The power (MW) analog input was changed from CH7 to CH3 so
FTAs are no longer required for generator control. In addition, that
input is now filtered using the PCV Filter Time Constant [PID:C Tf 1].
A Sync Speed Dead Zone Bias [PID:S r –] was added so the droop
control algorithm can be configured to ignore minor fluctuations of
the synchronous speed and electrical frequency.
The option of connecting a redundant power input was eliminated
(the Alternate MW Input [MODE:S SS 3] and MW Spread Alarm
Threshold [COND:S Alarm 3] parameters and "MW Spread" alarm
were removed).
The scaling of the power PV and SP readouts was adjusted so it
matches the corresponding measured variable if the Maximum MW
Signal [COND:D LVL 7] is less than 100 percent.

March 2021 Page 1 of 8 DS3307/V (2.1.0)

 Idle States A third idle speed was added, which works like but must be above
Idle2, by adding an Idle3 discrete input and Idl3 relay assignment,
Idle3 Speed [COND:S LVL 3 3] parameter, and Modbus Idle3 coil
and discrete. In addition, the Idle1 and Idle2 Speed key sequences
were changed from LVL 3 LOW and 3 HIGH to 3 1 and 3 2.
Aborting a ramped sequence no longer leaves the Run, Idle, or Stop
LED flashing—either the Idle or Run LED will light to indicate the set
point is below or above minimum governor.
Measured Variables Each Analog In menu item now displays a channel number and
8-character signal label on the third line of the status screen and a
numeric value and a 5-character units label on the fourth. The key
sequence for setting the Measured Variable Label [COND:D Display
0 # –] parameters was modified to also define the units label.
The COND:D Display 0 0 key sequence for restoring all eight default
signal labels was eliminated.
Modbus The Port 4 response delay was changed to match that of Port 3
(seven character minimum).
It is no longer possible to block Modbus read access (the Read and
Write Inhibit [MODE:D LOCK 1] parameter was removed).
The key sequence [MODE:D COMM 3 or 4] for selecting each port’s
baud rate and parity was modified to also select its register scaling.
The nominal maximum value of each variable (usually 100 percent)
can now be reported as 4000/0x0FA0, 4095/0x0FFF, or 64000/
0xFA00. The old Port 3 Modbus Register Scaling [MODE:D LOCK
7] parameter for Port 3 was removed.
Coils 1 through 8 can now be changed and read back, but are never
changed by the controller. The first two activate/de-activate relays
assigned the Co01 and Co02 functions, the other six do not affect
the controller in any way.
The read-only value of coil 00010 was changed from 0 to 1, which
distinguishes Series 3++ Controllers from their predecessors.
The previously mentioned Idle3 coil was added.
The Out Fail (10043), Speed Deviation (10044) and Position Fail
(10048) discretes were modified to indicate the corresponding con-
dition rather than unacknowledged alarms.
Discrete inputs were added to indicate Modbus writes are locked
out; low voltage; valve position, individual analog input, auxiliary
board, field device and redundant selector power failures; output
clamped high or low; speed switch 1 and 2; idle3 and stop states;
computer remote set point; cascade or limiting control enabled;
generator control enabled, breaker closed, droop selected, power
fallback, and maximum load; critical speed stalling; and manual
override active.

March 2021 Page 2 of 8 DS3307/V (2.1.0)

 Input registers were added for the 1.2, 3.3, 5.0, 15 and 24V power
voltages; board temperature; cascade/limiting variable and set
point; power variable and set point; and analog output readbacks.
A power set point holding register was added for the droop control
loop, so its set point can be entered in megawatts instead of setting
the speed droop set point in rpm.
Parameter Ranges The value of the Speed Dead Zone Bias [PID:S r 1] is now displayed
in rpm instead of percent (it can still range from 0 to 100 percent of
the maximum control speed).
Power Supply Alarm The Power Supply alarm and relay condition are now based on the
internal CPU/IO PCB voltage measurements. The Power Supply
Test Input [MODE:D fE 0] parameter was removed.
Relay Functions A DGI relay assigned function was added, which causes a discrete
output to track the corresponding input. If MODE:D RA 3 is set to
+DGI, for example, CR3 would activate whenever D3 is asserted.
A Rst relay assignment was added, which activates its relays for
one second when the controller is reset to its ready to start state.
A Strt relay assignment was added, which activates its relays for
one second when a startup reaches the minimum control speed.
An Idl3 relay assigned function was added (see Idle States)
Co01 and Co02 relay assigned functions were added, which causes
the discrete outputs to track the corresponding Modbus coils.
Shutdown Log The engineering panel Shutdown Log [MODE TEST 0] procedure
was replaced by a new status screen SD Log menu.
In addition, each log entry now includes the controller time of the
shutdown. A new engineering panel Set Clock [MODE TEST 9] key
sequence was added to support this feature.
Software Version The Program Version [MODE TEST 2] key sequence was modified
Display to display first the control program version, then the speed board
firmware version, and finally the field programmable gate array
(FPGA) firmware version.
Valve Position The "ActH" option for the First Output Assigned Variable [COND:D
OUT 1] and the "I/H Failure" alarm have been renamed "ActP" and
"PosFeedbck" to reflect the more general use of the associated fea-
ture as a valve position test.
The Rosemont 3311 I/P transducer is no longer supported. The
“ActT” First Output Assigned Variable [COND:D OUT 1] option, I/P
Failure alarm, and Modbus I/P Fail bit were eliminated.

1061-002 skipped

March 2021 Page 3 of 8 DS3307/V (2.1.0)

 1061-003 CRC: DB8F, ID Code: 2; Released: November 2007
Operating State The LCD Control and SD Log will now display:
• “Undefined” instead of "----------" for invalid codes, such as
those most likely stored for unused log entries;
• “AuxBoardSD” if the shutdown was triggered by a speed board
failure (new code 34); and
• “Tracking SD” instead of “Shutdown” if the controller was track-
ing its active peer when the shutdown occurred.
Transmitter Failure The transmitter high alarm was modified so it is never indicated for
any input whose parameter is set to 102.4, or is indicated only if the
input signal reaches the 21.0 mA threshold for Namur NE 43 smart
transmitters if that parameter is set to 102.3.

1061-004 CRC: 759A, ID Code: 5; Released: May 2008

Alarms Alarms are now allowed to be acknowledged during shutdown.
Rated Sequence Rated sequence can now be selected when the controller is in the
Run mode; when this happens the controller will switch to Local.
Speed Priority Improved speed priority operation by not triggering speed tracking
Operation unless the output is at the physical clamp AND the demand clamp.

1061-005 CRC: 059A, ID Code: 10; Released: May 2009

Improvements Added support for inverted engineering unit displays--where the
maximum value is less than the minimum value, and removed the
ability to switch to Manual while an ESD discrete is active.
Corrections Corrected a problem with critical zone stall not aborting the start
sequence.

1061-006 CRC: 8978, ID Code: 11; Released: February 2010

Improvements Increased the delay between Port 1 messages to lower serial port
loading, and decreased the possibility of missing a Modbus request
due to heavy communication loading.
Corrections Corrected possibility of delaying the start of the control loop due to
Modbus communications.
Corrected a problem with an Auxiliary Board failure shutdown being
displayed in the SD Log as “Undefined.” Log will now correctly indi-
cate “AuxBoardSD.”
FD24V Fail Alarm Clarified this alarm to mention that it is external, optional, generated
by a digital input, and only applicable if wired that way (May 2010).

March 2021 Page 4 of 8 DS3307/V (2.1.0)

 1061-007 CRC: 8F59, ID Code: 13; Released: July 2010
Improvements Modified redundant tracking so the tracked output is passed through
an 80 millisecond delay.
Trans Fail and Corrected the description for these in the Modbus data sheet:
Trans Fail # August 2010.

1062-001 CRC: 7238, ID Code: 18; Released: September 2012

Improvements Modified the [MODE LOCK 3] Store/Recall functions so they cannot
be activated unless [MODE LOCK 5] is enabled.
Added the ability to instantaneously change the frequency of the
controller’s beep sound to its highest value (silent) by pressing the
Scroll button and Limit 3 button at the same time.
August 29, 2013 (manual revision 1.4.1): Revised Tracking on page
67 to change wording from "Don’t assign..." Tracking function to
"best practice is not to assign..." Tracking function to an auxiliary
PCB input.
Overspeed Prevention Added the Overspeed Prevention function.
ESDae Added the ESDae discrete input, which triggers an ESD in all states
(including the Ready state) and does not allow the controller to be
Reset or switched to Manual while active.
Remote Serial SP Added COND:D GAIN 4 and COND:D BIAS 4 parameters for scal-
Scaling ing the Serial Remote Set Point from a companion Performance
controller.

1062-002 CRC: 50AB, ID Code: 24

Improvements Added a front face display for the parameter checksum.
Removed the possibility of a "Max Load" alarm when b3(S) = 100%.
Clamped the MW PV so it cannot go above 100%.
Disabled Port 1-3 serial port drivers during Loader operation to
avoid disrupting communication to other daisy-chained controllers.
Corrections Fixed possibility of sending a Run status over Port 1 while in Ready
if transitioning directly from Manual.

1062-003 CRC: 29CC, ID Code: 26; Released: February 2014

Improvements Removed the possibility of receiving a new Modbus request while in
the process of responding to a previous request.
Corrections Fixed problem with droop control not working because the droop
bias was not calculated properly. This error resulted in an effective
MW PV that was lower than the displayed value.
October 2014 (manual revision 1.5.1): Add CCC recommendation to
use DPM for new project installations, while upgrades can continue

March 2021 Page 5 of 8 DS3307/V (2.1.0)

 to use the auxiliary PCB high-current output, see High-Current Out-
put on page 60.
November 2014 (manual revision 1.5.2): Additional updates to
DS3307/O (p11 removed high-current) and DS3307/L (p7 removed
bipolar output) to support the previous (October 2014) update.

1062-004 CRC: 3A28, ID Code: 35; Released: February 2015

New Features Modified Modbus coil 00023 (Ready/Reset) so that setting the coil
while not in Shutdown can be used to clear all alarms.
Improvements Modified the overspeed prevention algorithm so it is disabled when
Prevention Speed [COND:S LVL HIGH] equals zero.
Modified the start sequence so that the Final Startup Ramp Rate
[COND:S LVL 6 HIGH] is used after the last configured Idle instead
of only after Idle2.
Removed the possibility of droop control when the controller is not in
Run.
Modified the GenPwr LED so it flashes mostly Off if when in Auto
and the breaker is closed, but the controller is not in Run.
Modified the "Drop" and "Isoc" relay assignments so that in Auto
they cannot be active unless the controller is in Run.
Modified the Speed SP when coming out of Redundant Tracking
into Isoch so the SP is initially set to sync speed.
Manual Updates June 17, 2015 (manual revision 1.6.1): added engineering panel
information to Appendix A.

1063-001 CRC: 530E, ID Code: 40; Released: December 2016

New Features Added Modbus input register 30033 -- Loop Counter.
Added "Trck" relay assignment.
Improvements Improved the precision when reading Modbus registers with 4095
scaling.
Modified the handling of Modbus register writes when the value is
above the scaling maximum so the request is ignored rather than
setting the register to the maximum value.
Modified the MODE LOCK 3 Recall function so it no longer requires
MODE LOCK 5 to be enabled.
Modified the Overspeed Prevention algorithm so it is disabled while
an Overspeed Trip Test is active.
Modified the "CRZ Stall" alarm so it cannot be cleared unless the
speed is outside the critical zone.
Modified the Port 1 status sent in Manual so extraction is not
allowed unless speed has reach minimum governor.

March 2021 Page 6 of 8 DS3307/V (2.1.0)

 Manual Updates March 2017:
• Added Caution to Note 4 of DS3307/M.
• Added debounce discussion to Discrete Inputs.

1063-002 CRC: 0484, ID Code: 46; Released: December 2017

Improvements Modified Modbus discrete 10052 (Low Clamp) so it is always active
if the output = 0%.
Modified Modbus discrete 10053 (High Clamp) so it is always active
if the output = 100%.
Modified the MPU displays so the RPM shows as "xxxx" when the
MPU is disabled, instead of blanking the entire line.
Modified the "stay in limit" logic so it is cleared whenever the output
reaches a clamp. Because the Limit LED is active during "stay in
limit," this change prevents the situation where the Limit LED could
remain active indefinitely due to clamping.
Removed the filtering of variables for loops that are disabled.
Removed the possibility of switching into the Loader when the Port 4
communication settings are not set to 19.2K baud and Odd parity.
Corrections Fixed problem with remote serial set point when MODE:D fE 3 was
enabled and COND:D GAIN 4 and COND:D BIAS 4 were not set to
1.00 and 0.00, respectively.
Fixed possibility of getting an "MW Fallback" alarm when generator
mode is disabled.
Manual Updates Corrected mis-numbering of Discrete Modbus addresses in descrip-
tion of Low Clamp and High Clamp.

1063-003 CRC: A0CC, ID Code: 48; Released: October 2018

Improvements Modified the "SPtk" relay assignment so it also becomes active
when in Remote and the analog remote SP is not active.
Modified the high actuator tracking release so it cannot occur if
speed is below minimum governor.
Modified the high and low clamp status so they can also be active in
situations where the output is beyond the clamp.
Corrections Fixed potential controller reset when trying to recall an alternate
parameter set with a Bad CRC ("No Match").
New Features Added an alarm for detecting low battery voltage on the RTC/RAM
chip. The status can only be checked on Rev B and higher CPU
boards. The alarm posted is "LowBattery".
Added Modbus discrete 10070 -- Low Battery.
Manual Updates Corrected description of Modbus Write Inhibit [MODE:D LOCK 2]
parameter in Modbus/OPC Configuration.

March 2021 Page 7 of 8 DS3307/V (2.1.0)

 1063-004 CRC: FF00, ID Code: 51; Released: September 2019
Improvements Modified the transition into redundant tracking so there is no initial
80ms output tracking delay.
Removed the restrictions that would not allow the cascade/limit SP
to be changed from the front face during Shutdown or the open loop
actuator ramp.
Corrections Fixed problem with not being able to switch into Remote if only
Lock8(D) was enabled.
Fixed problem with allowing a front face prompt to switch to Remote
even when all Remote SP sources were disabled.
Fixed problem with the cascade/limit SP clamps only being checked
when the cascade/limit loop menu was displayed on the front face.
FIxed problem with SpdUp/SpdDn discrete inputs not working when
the cascade/limit loop menu was displayed on the front face.
Fixed problem with resetting the failsafe timer during the open loop
actuator ramp if a new Rated/Idle request is received.
Fixed problem with Modbus input registers 30009 (RPM display)
and 30010 (SP display) not always representing the Speed and
Speed SP as intended. Theses Modbus registers reflected what
was being displayed for the PV & SP on the front face and would be
affected if an alternate loop was being displayed by the Casc, Limit
or Power keys.
New Features Removed Comm2(D) and hardcoded the baud rate for the unused
Port 2 at 9600 baud.
1063-005 CRC: 8B89, ID Code: 57; Released: March 2021
Improvements Modified the speed tracking status when Out1 High(S) = A0.0 so
that it is still activated when the output reaches the high clamp.
Corrections Fixed problem in Remote with Rated sequence releasing speed
track at Min Gov instead of waiting until the SP reached Rated.
Fixed possibility of sending a "Purge" status over Port 1 when
extraction is not enabled. When extraction is enabled, the same sta-
tus bit is used by the load shedding response (fD31) to put the
extraction in Idle.
Fixed problem with the valve droop PV not being updated while in
Tracking.
Fixed possibility of a non-existent actuator alarm when in Manual
with Rev1(S) enabled.

March 2021 Page 8 of 8 DS3307/V (2.1.0)

COMPRESSOR CONTROLS CORPORATION

Des Moines, IA, USA
Phone: (515) 270-0857 • Web: www.cccglobal.com
Printed in U.S.A.
 FM3307/C. Series 3++
Speed
Controller

# Speed Controller
Configuration Worksheet
Customer: CCC No.:
Completed By: Tag No.:
Date: Serial No.:
Software Rev.: 1063- Checksum:
Service:
Controller ID: Computer ID:

COND:C GROUP
SP HIGH SP LOW

MODE:C GROUP
fC 3 REV 1

PID:C GROUP
G PB 1 Td 1
Kr 1 r1 Tf 1

COND:D GROUP
BIAS 1 GAIN 2 OUT 1 OUT 3
BIAS 2 GAIN 4 OUT 1 – OUT 3 HIGH
BIAS 4 LVL 7 OUT 2 OUT 3 LOW
CONST 2 OUT 0 HIGH OUT 2 HIGH
GAIN 1 OUT 0 LOW OUT 2 LOW
DISPLAY 0 #
DISPLAY 0 # HIGH
DISPLAY 0 # LOW
DISPLAY 0 # •
DISPLAY 0 # –
EU
1 2 3 4 5 6 7 8
IN ##
01 02 03 04 05 06 07 08

09 10 11 12 13 14 15 16

March 2021 Page 1 of 4 FM3307/C (2.1.0)

 Series 3++ Speed Controller Configuration Worksheet
CCC No.: Tag No.: Date:

MODE:D GROUP
COMM 3 baud COMM 4 baud fE 1 LOCK 6
COMM 3 parity COMM 4 parity fE 3 LOCK 8
COMM 3 scaling COMM 4 scaling LOCK 0 REV 2
fC 0 LOCK 2 REV 3

AN IN #
AN IN # HIGH
AN IN # LOW
RA #
NO/NC
CR1 CR2 CR3 CR4 CR5 CR6 CR7 CR8 CR9

COND:S GROUP
ALARM 1 LVL 0 LVL 6 LOW SP 4 mode
ALARM 2 limit LVL 1 LVL 7 SP 4 speed
ALARM 2 delay LVL 2 LVL 8 HIGH SP 5 mode
CONST 1 LVL 3 1 LVL 8 LOW SP 5 speed
CONST 2 LVL 3 2 LVL 9 HIGH SP 6
CONST 3 LVL 3 3 LVL 9 LOW SP HIGH
CONST 4 LVL 4 OUT 1 HIGH SP LOW
DISPLAY HIGH LVL 5 OUT 1 LOW
DISPLAY LOW LVL HIGH SP 1
LVL – LVL 6 HIGH SP 2

0.000 0.111 0.222 0.333 0.444 0.555 0.666 0.777 0.888 1.000
f(X) 1 #
f(X) 2 #
f(X) 3 #
X4# 0.000 1.000
f(X) 4 #
0 1 2 3 4 5 6 7 8 9

March 2021 Page 2 of 4 FM3307/C (2.1.0)

 Series 3++ Speed Controller Configuration Worksheet
CCC No.: Tag No.: Date:

MODE:S GROUP
AN IN 1 fC 1 fD 3 3 MOR 1
AN IN 2 fC 2 fD 3 4 MOR 2
AN IN 3 fC 4 LOCK 6 1 MVAR
AN IN 4 fC 5 LOCK 6 2 REV 1
AN IN 5 fC 6 LOCK 9 SS 1
AN IN 6 fC 7

PID:S GROUP
G1 Kr – r1 Td 1
G2 PB 1 r– Td –
Kr 1 PB – Tf 4

SPEC:S GROUP
b1 b3 K

March 2021 Page 3 of 4 FM3307/C (2.1.0)

 Series 3++ Speed Controller Configuration Worksheet
CCC No.: Tag No.: Date:

March 2021 Page 4 of 4 FM3307/C (2.1.0)

COMPRESSOR CONTROLS CORPORATION

Des Moines, IA, USA
Phone: (515) 270-0857 • Web: www.cccglobal.com
Printed in U.S.A.
 FM3307/L. Series 3++ Speed Controller

# Speed Controller
Configuration Planner
Customer: CCC No.:
Completed By: Tag No.:
Date: Serial No.:
Software Rev.: 1063- Checksum:
Service:
Controller ID: Computer ID:

Turbine Speed Profile

Valid Speed Range (see Chapter 4 of UM3307)
Maximum Control Speed [COND:S DISPLAY HIGH] 64000 rpm
Control Threshold [COND:S ALARM 1] rpm
Control Range (see Chapter 4 of UM3307)
Minimum Control Speed [COND:S DISPLAY LOW] rpm
Electronic Overspeed Trip [COND:S LVL 5] rpm
Normal Operating Range (see Chapter 4 of UM3307)
Minimum Governor [COND:S SP LOW] rpm
Maximum Governor [COND:S SP HIGH] rpm
Critical Speed Ranges (see Chapter 4 of UM3307)
First Critical Speed Lower Limit [COND:S LVL 8 LOW] rpm
First Critical Speed Upper Limit [COND:S LVL 8 HIGH] rpm
Second Critical Speed Lower Limit [COND:S LVL 9 LOW] rpm
Second Critical Speed Upper Limit [COND:S LVL 9 HIGH] rpm
Idle and Rated Speeds (see Chapter 4 of UM3307)
Idle1 Speed [COND:S LVL 3 1] rpm
Idle2 Speed [COND:S LVL 3 2] rpm
Idle3 Speed [COND:S LVL 3 3] rpm
Rated Speed [COND:S LVL 4] rpm
Speed Switches (see Chapter 4 of UM3307)
Switch 1 Mode [COND:S SP 4] +Latch / +NLatc / –Latch / -NLatc
Switch 1 Speed [COND:S SP 4] rpm
Switch 2 Mode [COND:S SP 5] +Latch / +NLatc / –Latch / -NLatc
Switch 2 Speed [COND:S SP 5] rpm
Select + to activate Speed Switch when NPT is above specified limit or – to activate it below that limit.
A LATCHed speed switch generates an alarm that must be acknowledged.

March 2021 Page 1 of 8 FM3307/L (2.1.0)

 Series 3++ Speed Controller Configuration Planner
CCC No.: Tag No.: Date:

Speed Set Point (see Chapter 5 of UM3307)

Analog Remote Set Point [COND:S SP 2] Off / 1 to 8 (Channel #)
Serial Remote Set Point [MODE:S fC 4] Off / 1 to 8 (Controller ID)
Dual-Loop/ Performance RSP [MODE:S LOCK 9] Off for Perf, On for Dual-Loop
Computer Remote Set Point [MODE:D LOCK 8] Off for local, On for remote
Remote Set Point Reverse [MODE:D fE 3] Off / On
General Set Point Ramp Rate [PID:S G 1] 999 rpm/sec
RSP Filter Time Constant [PID:S Tf 4] 99.9 sec
Local Set Point Ramp Rate [COND:S SP 1] 999 rpm/sec
Remote Set Point Scaling Gain [COND:D GAIN 4] 0.00 to 9.99
Remote Set Point Scaling Bias [COND:D BIAS 4] –99.9 to 99.9

Speed Control Loop (see Chapter 5 of UM3307)

Speed Proportional Band [PID:S PB 1] 006 to 999
Characterizer Argument [MODE:S SS 1] Off for speed / On for valve position
Proportional Band Characterizer [COND:S f(X) 1 #] 1.00  f(X)  9.99
N or CR: 00.0 11.1 22.2 33.3 44.4 55.5 66.6 77.7 88.8 100.0
PB/PB1:
0 1 2 3 4 5 6 7 8 9
Speed Reset Rate [PID:S Kr 1] 99.9 rpts/min
Reset Rate Characterizer [COND:S f(X) 2 #] .000  f(X)  .999
N or CR: 00.0 11.1 22.2 33.3 44.4 55.5 66.6 77.7 88.8 100.0
Kr/Kr1:
0 1 2 3 4 5 6 7 8 9
Speed Derivative Coefficient [PID:S Td 1] 9.99 sec
Speed Dead-Zone Bias [PID:S r 1] rpm
Dead-Zone Characterizer [COND:S f(X) 3 #] .000 f(X) .999
N or CR: 00.0 11.1 22.2 33.3 44.4 55.5 66.6 77.7 88.8 100.0
r/r1:
0 1 2 3 4 5 6 7 8 9

Speed Deviation Alarm (see Chapter 5 of UM3307)

Deviation Alarm Threshold [COND:S ALARM 2] rpm
Deviation Alarm Delay [COND:S ALARM 2] 9.96 sec

March 2021 Page 2 of 8 FM3307/L (2.1.0)

 Series 3++ Speed Controller Configuration Planner
CCC No.: Tag No.: Date:

Overspeed Protection
Electronic Overspeed Trip (see Chapter 8 of UM3307)
This feature is configured by setting the Electronic Overspeed Trip speed (see Control Range).
Overspeed Trip Test (see Chapter 8 of UM3307)
Overspeed Trip Test [MODE:S fC 2] Off / On
Load Loss Response (see Chapter 8 of UM3307)
Default Set Point [COND:S CONST 1] rpm
Overspeed Prevention (see Chapter 8 of UM3307)
Prevention Speed [COND:S LVL HIGH] rpm
OSP Output Step Size [COND:S CONST 3] 0 to 99.9%
OSP Minimum Step Time [COND:S CONST 4] 0 to 9.96 seconds

Cascade / Limiting Loop (see Chapter 5 of UM3307)

Cascade / Limiting Loop [MODE:S fC 1] Off / On (Off for neither)
Limiting Control [MODE:S MVAR] Off for cascade, High or Low for limit
PCV Direction of Action [MODE:C REV 1] Off / On
PCV Maximum Set Point [COND:C SP HIGH] 99.9 %
PCV Minimum Set Point [COND:C SP LOW] 99.9 %
PCV Proportional Band [PID:C PB 1] 006 to 999
PCV Reset Rate [PID:C Kr 1] 99.9 rpts/min
PCV Derivative Coefficient [PID:C Td 1]  9.99 sec
PCV Filter Time Constant [PID:C Tf 1] 99.9 sec
Cascade Control (see Chapter 5 of UM3307)
PCV Dead-Zone Bias [PID:C r 1]  99.9 %
PCV Set Point Recall [MODE:C fC 3] Off / On saves SP in manual
PCV Set Point Ramp Rate [PID:C G] 9.99 rpts/min
Minimum Load [SPEC:S b 1] 100.0 % cascade or droop
Maximum Load [SPEC:S b 3] 100.0 % cascade or droop

Intended Valve Position

Demand Clamps (see Chapter 7 of UM3307)
Maximum Demand Clamp [COND:S OUT 1 HIGH]  100.0 %
Minimum Demand Clamp [COND:S OUT 1 LOW]  99.9 %
Extraction Control Interface (see Chapter 7 of UM3307)
Extraction Controller ID [MODE:D fC 0] Off / 1 to 8 (Extraction Controller ID)
V1 Maximum Clamp [COND:D OUT 0 HIGH]  100.0 %
V1 Minimum Clamp [COND:D OUT 0 LOW]  100.0 %

March 2021 Page 3 of 8 FM3307/L (2.1.0)

 Series 3++ Speed Controller Configuration Planner
CCC No.: Tag No.: Date:

Generator Control
Basic Operation (see Chapter 6 of UM3307)
Generator Control [MODE:S fC 5] Off / On
MW Droop Control [MODE:S fC 6] Off for valve droop, On for MW
Isochronous Control (see Chapter 6 of UM3307)
This loop uses the same tuning coefficients as the Speed Control Loop.
Droop Control (see Chapter 6 of UM3307)
Droop Control Gain [SPEC:S K] 100.0
Droop Proportional Band [PID:S PB –] 006 to 999
Droop Reset Rate [PID:S Kr –] 99.9 rpts/min
Droop Derivative Coefficient [PID:S Td –] 9.99 sec
Sync Speed Dead-Zone Bias [PID:S r –] rpm
Megawatt Droop (see Chapter 6 of UM3307)
Maximum MW Signal [COND:D LVL 7] 100.0 %
Valve Droop (see Chapter 6 of UM3307)
Generated Power Characterizer [COND:S f(X) 4 # and X 4 #] 00.0  MW  99.9 %
CR (%): 00.0 100.0
MW (%):
0 1 2 3 4 5 6 7 8 9

Load Limits (see Chapter 6 of UM3307)

Remote Maximum Load Limit [MODE:S fC 7] Off for b 3, On for PV6
Droop control uses the same load limit parameters as Cascade Control.
Breaker Fallback (see Chapter 6 of UM3307)
Breaker Shutdown Fallback [MODE:S fD 3 3] Off for fD 34 or On for ESD
Breaker Rated Fallback [MODE:S fD 3 4] Off for MinGov, On for Rated

March 2021 Page 4 of 8 FM3307/L (2.1.0)

 Series 3++ Speed Controller Configuration Planner
CCC No.: Tag No.: Date:

Automatic Sequences
Start-Up Sequence (see Chapter 8 of UM3307)
Actuator Ramp Rate [PID:S G 2] 9.99 %/sec
Start-Up Valve Limit [COND:S LVL 0] 99.9 %
Initial PID Output [COND:S LVL –] 99.9 %
Initial Startup Ramp Rate [COND:S LVL 6 LOW] 999 rpm/sec
Final Startup Ramp Rate [COND:S LVL 6 HIGH] 999 rpm/sec
Failsafe Timer [COND:S LVL 2] 999 sec
Stop Sequence (see Chapter 8 of UM3307)
Shut-Down Delay [COND:S LVL 1] 999 sec
Shutdown Ramp Rate [COND:S LVL 7] 999 rpm/sec
Critical Speed Avoidance (see Chapter 8 of UM3307)
Critical Speed Ramp Rate [COND:S SP 6] rpm/sec
Critical Stall Time [COND:S CONST 2] 999 sec

Manual Operation (see Chapter 7 of UM3307)

Manual Operation [MODE:S MOR 2] Off / On to permit manual
Manual Override [MODE:S MOR 1] Off / On disables automatic protection
Remote Manual is enabled by assigning any discrete input the ReMan function.

Redundant Tracking (see Chapter 3 of UM3307)

Redundant Tracking [MODE:D fE 1] Off / On enables tracking
Modbus While Tracking [MODE:D LOCK 0] Off / On requires different IDs

March 2021 Page 5 of 8 FM3307/L (2.1.0)

 Series 3++ Speed Controller Configuration Planner
CCC No.: Tag No.: Date:

Speed Inputs (see Chapter 4 of UM3307)

Speed Input 1 [MODE:S ANIN 1] Off / On
Speed Input 2 [MODE:S ANIN 2] Off / On
Speed Input 3 [MODE:S ANIN 3] Off / On
MPU Tolerance [MODE:S ANIN 4] 1 to99 rpm
Gear Tooth Count [MODE:S ANIN 5] 999 speed gear teeth
Shaft Speed Ratio [MODE:S ANIN 6] 9.999 main / gear shaft rpm

Analog Inputs (see Chapter 3 of UM3307)

Variable:
CH1 CH2 CH3 CH4

CH5 CH6 CH7 CH8

Transmitter Testing (see Chapter 3 of UM3307)

Analog Input High Alarm Limit [MODE:D ANIN # HIGH] 102.4 %
Analog Input Low Alarm Limit [MODE:D ANIN # LOW] 102.4 %
High:
Low:
1 2 3 4 5 6 7 8

Signal Variables (see Chapter 3 of UM3307)

Offset Zero Input [MODE:D ANIN #] Off / On
Enable:
1 2 3 4 5 6 7 8

Measured Variables (see Chapter 3 of UM3307)

Measured Variable Display [COND:D DISPLAY 0 #] Off / On
Measured Variable Maximum [COND:D DISPLAY 0 # HIGH] –9999 to 9999
Measured Variable Minimum [COND:D DISPLAY 0 # LOW] –9999 to 9999
Measured Variable Decimal [COND:D DISPLAY 0 # •] 0 to 4 1 = ###., 4 = .###
Measured Variable Name and Units [COND:D DISPLAY 0 # –] 8 Characters for Name, 5 for Units
Enable:
High:
Low:
Decimal:
Name:
Units:
1 2 3 4 5 6 7 8

March 2021 Page 6 of 8 FM3307/L (2.1.0)

 Series 3++ Speed Controller Configuration Planner
CCC No.: Tag No.: Date:

Analog Outputs
Output Reverse (see Chapter 7 of UM3307)
Output Reverse [MODE:S REV 1] Off / On if signal-to-close valve
High-Current Output (see Chapter 3 of UM3307)
First Output Assigned Variable [COND:D OUT 1] see Table 3-3
Output Scaling Bias [COND:D BIAS 1]  .9999
Output Scaling Gain [COND:D GAIN 1]  .9999
Loopback Scaling Bias [COND:D BIAS 2] –.9999 to .9999
Loopback Scaling Gain [COND:D GAIN 2]  99.99
Output Failure Delay [COND:D CONST 2] 9.96 sec
Standard Analog Outputs (see Chapter 3 of UM3307)
Second Output Assigned Variable [COND:D OUT 2] see Table 3-3
Second Output Scale Maximum [COND:D OUT 2 HIGH] 99.9 %
Second Output Scale Minimum [COND:D OUT 2 LOW] 99.9 %
Second Output Reverse [MODE:D REV 2] Off / On
Third Output Assigned Variable [COND:D OUT 3] see Table 3-3
Third Output Scale Maximum [COND:D OUT 3 HIGH] 99.9 %
Third Output Scale Minimum [COND:D OUT 3 LOW] 99.9 %
Third Output Reverse [MODE:D REV 3] Off / On

March 2021 Page 7 of 8 FM3307/L (2.1.0)

 Series 3++ Speed Controller Configuration Planner
CCC No.: Tag No.: Date:

Discrete Inputs (see Chapter 3 of UM3307)

Discrete Input Assigned Function [COND:D IN ##]  function from Table 3-4
function:
01 02 03 04 05 06 07 08
function:
09 10 11 12 13 14 15 16

Control Relays (see Chapter 3 of UM3307)

Relay Assigned Function [MODE:D RA #]  function from Table 3-5
function:
NO/NC:
DO1 DO2 DO3 DO4 DO5 DO6 DO7 DO8 JP1
CR1 CR2 CR3 CR4 CR5 CR6 CR7 CR8 CR9
DO switches are on CPU/IO PCB, JP1 is on the Auxiliary PCB Daughter Board.

Disabling Input Signals (see Chapter 3 of UM3307)

CPU Inputs Lockout [MODE:D LOCK 6] Off / On
Auxiliary I/O Lockout [MODE:S LOCK 6 1] Off / On
Speed Inputs Lockout [MODE:S LOCK 6 2] Off / On

Serial Ports
ID Numbers (see Chapter 3 of UM3307)
Controller ID Number [MODE:D COMM 0] 1 to 8 for Port 1
Computer ID Number [MODE:D COMM 0 •] 1 to 64 for Ports 2, 3, & 4
Serial Communication Formats (see Chapter 3 of UM3307)
Port 3 Baud Rate [MODE:D COMM 3] 4800 / 9600 / 19.2k
Port 3 Parity [MODE:D COMM 3] Odd / Even / None
Port 3 Scaling [MODE:D COMM 3] 4000 / 4095 / 64000
Port 4 Baud Rate [MODE:D COMM 4] 4800 / 9600 / 19.2k
Port 4 Parity [MODE:D COMM 4] Odd / Even / None
Port 4 Scaling [MODE:D COMM 4] 4000 / 4095 / 64000
Modbus/OPC Configuration (see Chapter 3 of UM3307)
Modbus Write Inhibit [MODE:D LOCK 2] Off / On for read-only

March 2021 Page 8 of 8 FM3307/L (2.1.0)

COMPRESSOR CONTROLS CORPORATION

Des Moines, IA, USA
Phone: (515) 270-0857 • Web: www.cccglobal.com
Printed in U.S.A.
FM73

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Publication Title: Series 3++ Speed Controller
Publication No.: UM3307 (2.1.0) Publication Date: March 2021

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October 2020 FM73 (5.0)