SECTION 5531

NP7 - 035
ISSUE 8
August 1997

POWER FACTOR CONTROLLER

(PFC3) Part No: E000-21030.
(PFC3) Part No: E000-22090.

Installation
and Adjustments Manual.
 SAFETY PRECAUTIONS
Before operating the generating set, read the generating set
operation manual and this generator manual and become familiar
with it and the equipment.

SAFE AND EFFICIENT OPERATION CAN ONLY BE

ACHIEVED IF THE EQUIPMENT IS CORRECTLY
OPERATED AND MAINTAINED.

Many accidents occur because of failure to follow fundamental

rules and precautions.

ELECTRICAL SHOCK CAN CAUSE SEVERE

PERSONAL INJURY OR DEATH.

• Ensure installation meets all applicable safety and local electrical

codes. Have all installations performed by a qualified electrician.

• Do not operate the generator with protective covers, access

covers or terminal box covers removed.

• Disable engine starting circuits before carrying out maintenance.

• Disable closing circuits and/or place warning notices on any circuit

breakers normally used for connection to the mains or other
generators, to avoid accidental closure.

Observe all IMPORTANT, CAUTION, WARNING, and

DANGER notices, defined as:

Important ! Important refers to hazard or unsafe

method or practice which can result in
product damage or related equipment
damage.

Caution ! Caution refers to hazard or unsafe

method or practice which can result
in product damage or personal injury.

Warning refers to a hazard or unsafe

method or practice which CAN result
in severe personal injury or possible
Warning ! death.

Danger refers to immediate hazards

which WILL reult in severe personal
injury or death.
Danger !

Due to our policy of continuous improvement, details in this manual which were
correct at time of printing, may now be due for amendment. Information included
must therefore not be regarded as binding.
 CONTENTS
SAFETY PRECAUTIONS IFC
SECTION 1 GENERAL DESCRIPTION 3

SECTION 2 PRINCIPLE OF OPERATION 4

2.1 Power Factor Control Mode 4
2.2 VAr Control Mode 4
2.3 Generator Current Limiting 4
2.4 Low Excitation Limiting 4
2.5 Voltage Matching Mode 6
2.6 Dead-Band or Dynamic Control Modes 6

SECTION 3 INSTALLATION 8
3.1 General 8
3.2 Generating Set Protection; General 8
3.3 Basic Operation - Power Factor
Control of Individual Generator(s) - Fig 6 8
3.3.1 Voltage Input ( E2 , E1 ) 8
3.3.2 Current Input ( S1 , S2 ) 8
3.3.3 AVR Control Output ( A1 , A2 ) 11
3.3.4 Circuit Breaker Input (CB1 , CB2 ) 11
3.4 Installing Options - Fig 8 11
3.4.1 Remote Power Factor (VAr) Adjustment - <1> 11
3.4.2 Remote Switching of Power Factor/VAr Mode - <2> 11
3.4.3 Generator Current Limiting - <3> 11
3.4.4 Excitation Voltage Limiting - <4> 11
3.4.5 Voltage Matching - <5> 11
3.5 PFC3 used for Power Factor Correction - Fig 9 11

SECTION 4 COMMISSIONING AND ADJUSTMENTS 15

4.1 Installations 15
4.2 Commissioning Basic System 15
4.2.1 Preliminary Adjustments 15
4.2.2 Droop Setting 16
4.2.3 PFC3 Setting 17
4.3 Commissioning Options 17
4.3.1 Voltage Matching Option 17
4.3.2 Current Limiting Option 18
4.3.3 Low Excitation Limiting Option 18
4.3.4 Dead-Band and Dynamic Control Options 19
4.4 Power Factor Correction 19

SECTION 5 USER ADJUSTABLE CONTROLS AND SELECTION LINKS 20

5.1 Light Emitting Diode (led) Indicators 20

5.2 Selection Links & Switches 20

SECTION 6 OPERATION 22

6.1 General 22
6.2 Combined Heat And Power Installations 22
6.3 Peak Lopping Installations 22
6.4 Power Factor Correction 22
6.5 Synchronous Motors 22
6.6 Overvoltage 22

SECTION 7 TROUBLE SHOOTING 23

SECTION 8 TECHNICAL SPECIFICATION 24

1
Newage International STRONGLY recommend that when a PFC3 is used
then "Loss of Excitation" tripping should also be used.

2
 SECTION 1
GENERAL DESCRIPTION

The Power Factor Controller (PFC3) is designed to control the

power factor reactive current (VAr) of a generator whilst running
in parallel with the mains utility.

The PFC3 is also equipped with a voltage matching facility for

use with automatic synchronisation equipment. This dispenses
with the need for motorised potentiometers and allows a lower
cost synchroniser to be used.

The PFC3 can also be connected to provide power factor

correction of the incoming mains feeder by using the generator
to supply the reactive current. A current limiting facility is provided
to prevent generator overload.

The control loop within the PFC3 has two modes of operation to
allow for the best response matching of the prime-mover governor
and the generator voltage regulator. 'Dynamic Control' is the
preferred method providing continuous correction and high
accuracy. 'Deadband Control' provides an alternative means
which allows the power factor (or VAr) to drift between presettable
Fig. 1b Basic Power Factor Control
limits before any correction signal is given. This method is
employed where system stability may be a problem.

The output of the PFC3 is internally limited to restrict the

maximum (or minimum) voltage of the generator under abnormal
operating conditions. This prevents the generator from trying to
match an unrealistic mains voltage and also limits the consumer
bus-bar voltage in the event of a mains failure.

The PFC3 incorporates an excitation limiting circuit to prevent

the generator excitation from being driven to zero (or near zero)
when operating at leading power factor.

Due to its flexibility the PFC3 can be used in many different

single or multi-generator power schemes as shown in Fig 1a
through Fig 1d and the more unusual applications may not be
covered in this manual. If you are in any doubt as to the use of
the PFC3 in your application please contact your nearest Newage
International office for advice.

Fig. 1c Power Factor Correction

Fig. 1a Basic Power Factor Control

Fig. 1d Power Factor Correction

3
 SECTION 2
PRINCIPLE OF OPERATION
The following description makes reference to the block diagram comparator/amplifier in such a way as to override normal PF or
shown in Fig 2 ( Principle of Operation ). VAr control should excess current be detected. With this feature
connected, normal power factor (or VAr) control is provided
Signals representing generator voltage and current are fed into UNTIL the set current limit is reached, at which point the output
the PFC3 via isolation transformers and are used for various to the AVR restricts further increases in exported (or imported)
tasks within the unit. generator current. The level at which current limiting applies is
set using the appropriate circuit board control.
Two measuring circuits (the Active Current Transducer and the
Reactive Current Transducer) use both voltage and current 2.4 Low Excitation Limiting
signals to produce internal dc references proportional to
generator kW and kVAr. The voltage input is also used to provide In applications requiring the generator to operate at leading power
internal power supplies and further internal circuits measure the factor, the level of VAr imported may cause the generator to
incoming voltage for voltage matching purposes. reach an unstable region due to self excitation. This can result
in the loss of synchronisation and the associated large circulating
The PFC3 is capable of operating in a variety of modes with currents may cause circuit breakers to trip or even equipment
internal switching circuits routing the necessary control signals damage.
to the main comparator/amplifier.
The PFC3 incorporates the necessary circuits to implement low
2.1 Power Factor Control Mode excitation limiting. The output of a separate excitation voltage
measuring transducer is fed to the input of the main comparator/
amplifier in such a way as to override normal PF or VAr control
In the 'Power Factor' mode of operation, the measured reactive
should low excitation be detected. With this feature connected,
current is compared to a proportion of the measured active
normal power factor (or VAr) control is provided UNTIL the set
current as set on the VAr/PF control potentiometer. If the
low excitation limit is reached, at which point the output to the
measured reactive current rises above the 'kW' signal, then the
AVR restricts further increases in imported generator current.
PFC3 acts to reduce the internal set-point of the AVR (via
The level at which low excitation limiting applies is set using the
terminals A1 and A2) and brings the generated VAr (and hence
appropriate circuit board control. The circuit is automatically
power factor) to the correct controlled level. If the measured
disabled if left unconnected.
reactive current is lower than required then the reverse action
takes place. Under these conditions, closed-loop control of
generator power factor is achieved. The PFC3 incorporates two more features which provide the
user with the choice of additional operating modes not normally
encountered in small/medium sized installations.
2.2 VAr Control Mode

In the 'VAr' mode of operation, the measured reactive current is

compared to a reference level derived from the setting on the
PF/VAR control potentiometer. If the measured reactive current
rises above this set-point, then the PFC3 acts to reduce the
internal set-point of the AVR (via terminals A1 and A2) and brings
the generated VAr to a controlled level. If the measured VAr is
lower than the demand then the reverse action takes place. Under
these conditions, closed-loop control of generated reactive
current is achieved.

The PFC3 incorporates circuits to provide a level of protection

to the generator not normally encountered in small/medium sized
installations.

2.3 Generator Current Limiting

Under normal circumstances the sizing of the generator set will

be such that the kW transfer to the mains (and hence the
generated VAr) will be limited by the engine and its fuel system.
In applications using the generator as power factor 'correction'
of the incoming mains this limiting does not apply and the level
of VAr demanded is a function of the feeder load. This can be
many times the rating of the generator set (particularly under
fault conditions) and must be protected against.

The PFC3 incorporates the necessary circuits to implement

generator current limiting. The output of a separate reactive
current measuring transducer is fed to the input of the main
4
5

Fig. 2 Principle of Operation

2.5 Voltage Matching Mode

The PFC3 is equipped with a second set of voltage input terminals

which are supplied (optionally) with a signal representative of
the load bus voltage. It is essential that this signal is fully
transformer isolated and is approximately 110Vac. If enabled;
and prior to the arrival of the closure signal from the generator
circuit breaker; the difference between the signals representing
the generator and bus voltages is fed to the input of the main
comparator/amplifier and adjusts the AVR set-point until both
signals match. The circuit is automatically disabled when the
generator circuit breaker closes. The table shown in Fig 3 explains
the operation of the PFC3 when connected for voltage matching.

E1/E2 CB1/CB2 L1/L2 OPERATING

SUPPLY CONTACT SUPPLY MODE
AVR
NONE
ON OPEN CONTROL
PRESENT
ONLY
VOLTAGE
APPROX
ON OPEN MATCHING
110V
MODE
PF
ON CLOSED X CONTROL
MODE
AVR
OFF X X CONTROL
ONLY

Fig. 3 Voltage Matching Mode

2.6 Dead-Band or Dynamic Control Modes

The PFC3 can be set to operate in one of two control modes

dependent upon the requirements of the installation.

In dynamic mode, the output from the PFC3 continually adjusts

the AVR set-point in response to the smallest change in power
factor (or reactive current). In dead-band mode, the power factor
(or reactive current) is allowed to vary between user settable
limits before any adjustment is made. Dead-band mode results
in a less accurate control but can eliminate problems of stability
caused by interaction with engine governing systems.

6
Fig 4 (Dead-band vs Dynamic) shows diagramatically the difference between dead-band and dynamic control modes and the effect
of the [ BAND ] control as seen on a typical power factor meter.

Fig. 4 Dead-Band vs Dynamic

Fig 5 (Dead-band Control Action) further explains the operation of the PFC3 when set in dead-band control mode.

Fig. 5 Dead-Band Control Action

7
 SECTION 3
INSTALLATION
3.2 Generating Set Protection; General
DO NOT defeat or otherwise disable
any system interlocks whilst installing Unless adequate protection is installed, engine control system
this equipment. malfunction or poor set-up can cause engine over-load or reverse
Warning ! power conditions resulting in damage to the engine.
Generator control system malfunction or poor set-up can cause
generator over-current or loss of synchronism (pole-slipping)
resulting in severe damage to the generator.
To prevent personal injury or damage
to equipment, only qualified personnel Generator Over-current Protection
should install or operate this unit.
Warning ! It is the responsibility of the Generating Set Assembler to ensure
that adequate protection systems are installed to trip the
Important ! The use of Megger or High Potential generator circuit breaker in the event of generator over-current.
test equipment may result in damage
Excitation Loss Protection
to this unit. Disconnect all leads
before using such equipment. It is the responsibility of the Generating Set Assembler to ensure
that adequate protection systems are installed to trip the
3.1 General generator circuit breaker in the event of loss of synchronism.
Newage International Ltd. can supply a suitable unit for linking
The Power Factor Controller PFC3 incorporates as standard with the generator circuit breaker and control gear. Please refer
many features which enable it to be used in a wide range of to factory for details.
applications. These features may be used in any combination
Automatic Synchronisers
depending upon the requirements of the end user.
It is the responsibility of the Generating Set Assembler to ensure
It is assumed that the AVR is ready wired to the generator as that adequate protection systems are installed for Automatic
specified in the appropriate machine wiring diagram. Synchronising of AC Generators.
The following Automatic Synchroniser settings are recommended
In ALL applications of the PFC3, the AVR and generator MUST when using PFC3:-
be equipped with a standard Quadrature Droop Paralleling kit. Generator frequency mismatch 0.1 Hz
This is shown in all figures fitted in 'W' phase (the more normal Voltage mismatch +/-3%
position). For exact details refer to the wiring diagrams supplied CB closing angle +/-10 degrees
with your generator.
Over/Under Voltage Protection
The PFC3 should be located in a clean, vibration free
environment, typically on the back panel of a control cubicle. If It is the responsibility of the Generating Set Assembler to ensure
the unit is for machine mounting it will have been supplied without that adequate protection systems are installed to prevent damage
metalwork and MUST be fitted on anti-vibration mounts equal to to the generator or connected equipment in the event of over or
those of the AVR. under voltage caused by malfunction/poor set-up of the control
system.
All wiring should be carried out using cables rated at 6A/600V
3.3 Basic Operation - Power Factor Control of
(minimum 0.75mm sq : 20AWG). For details of the AVR wiring,
reference should be made to the wiring diagrams supplied with Individual Generator(s) - Fig 6
your generator.
This is the simplest configuration involving one or more
generators coupled to the mains bus.
Different applications may demand the installation of one or more
of the optional features offered in the PFC3. Four typical 3.3.1 Voltage Input ( E2 , E1 )
configurations are described in this manual.
These are connected to the generator output terminals (normally
Fig 6 - Basic Operation - Power Factor Control of Individual 'U' phase and Neutral) and act as the power supply to the unit as
Generators well as its sensing input. The maximum voltage allowed at these
terminals is 277Vac/60Hz. If local regulations demand supply
fuses, then these should be rated at 5A.
Fig 7 - Replacing earlier VAr2 with the PFC3
3.3.2 Current Input ( S1 , S2 )
Fig 8 - Maximum configuration - All Options Fitted
These are connected to the generator current sensing C/T having
Fig 9 - PFC3 used for Power Factor Correction a secondary rating of 5A. This MUST be positioned in the correct
phase and with the correct polarity for successful operation of
the PFC3. See wiring diagrams for details of your particular
IF IN DOUBT - REFER TO FACTORY machine. If local regulations demand, then either lead S1 or S2
may be grounded.

8
3.3.3 AVR Control Output ( A1 , A2 ) Important ! Do NOT ground the screen at the
switch end. Simply leave the screen
These are connected directly to the corresponding terminals on unconnected and insulated.
the AVR. Should the cable length between the PFC3 and the
AVR exceed 5m (16ft) then it is advisable to use screened leads 3.4.3 Generator Current Limiting - <3>
with the cable screen connected to terminal A1.
Under certain operating conditions it is desirable to be able to
Important ! Do NOT ground the screen at either end.
limit the maximum current delivered by the generator. Connect
the current transformer to the terminals 0V and ILIM as shown.
3.3.4 Circuit Breaker Input ( CB1 , CB2 ) The current transformer should have a secondary current output
of 0.32A (class index 3.0) at 100% generator output and must
Contact closure of these terminals switches the PFC3 into power be positioned in the correct phase and with the correct polarity
factor (or VAr) control operation. These two terminals would for the successful operation of the PFC3. See loose leaf wiring
normally be connected to a normally open auxiliary contact on diagrams for details of your particular machine. Bar mounted
the generator circuit breaker. current transformers with the correct secondary rating and
mechanical fixings are available from Newage International.
In the case of multi-generator installations, where the generator
can run off-grid in parallel (island system), then a normally open Important ! Do NOT ground either lead S1 or S2 of
auxiliary contact from the incoming mains circuit breaker/ the current limiting C/T circuit.
contactor MUST be connected in series with the 'E2' supply to
the PFC. The voltage matching facility will then NOT operate in 3.4.4 Excitation Voltage Limiting - <4>
island operation. (See Fig 9).
Under certain operating conditions it is desirable to be able to
Where the PFC3 is used to replace an earlier VAr-2 then the limit the minimum excitation voltage (and therefore excitation
alternative wiring as shown in Fig 7 can be used. This will current) to prevent generator pole slipping. All that is required to
eliminate the need for any wiring changes when fitting the new enable this facility is to install two wires from X and XX (exciter
PFC3. 'Voltage matching' will NOT operate with this wiring field + and -) on the generator to the terminals X and XX on the
configuration. PFC3. See loose leaf wiring diagrams for any additional details
of your particular machine.
3.4 Installing Options - Fig 8
Important ! Do NOT ground either lead X or XX.
If it is required to expand on the basic use of the PFC3 and to
use one or more of the built-in options then the following notes 3.4.5 Voltage Matching - <5>
apply.
Under certain operating conditions it is desirable to use the
Note: The numbers in the <brackets> refer to the relevant feature voltage matching facility built into the PFC3. The inputs L1 and
shown in Fig 8. L2 have been designed to accept a standardised 110-120Vac
supply from the customers low, medium or high voltage bus. In
3.4.1 Remote Power Factor (VAr) Adjustment - <1> ALL cases the supply to the PFC3 MUST be isolated using a
suitable transformer but unlike the other unit inputs, the phasing
is unimportant. The input burden is typically 5VA.
Should front panel/remote adjustment of power factor or VAr be
required then a 10k ohm / 1W potentiometer may be connected Important ! Do NOT ground either lead L1 or L2.
to terminals RX, RY and RZ as shown. The use of screened
leads is essential with the screen connected to the adjacent
'0V' terminal.
3.5 PFC3 used for Power Factor Correction - Fig 9

Important ! Do NOT ground the screen at the It may be a requirement of certain applications to use the installed
potentiometer end. Simply leave the generating capacity in conjunction with the PFC3 to 'correct the
screen unconnected and insulated. power factor' of the incoming mains supply (at the consumers
incoming tie with the mains). In all cases it is necessary to protect
When fitted, the external potentiometer has complete control the generator against excessive current demand by fitting the
over the PFC3 set-point and the on-board adjustment is no longer current limiting option.
effective.
The current limiting transformer(0.32A sec) MUST be fitted in
3.4.2 Remote Switching of Power Factor/VAr the generator output (as shown in Fig 9) and must be correctly
phased.
Mode - <2>
The power factor control current transformer (5A sec) MUST be
Should front panel/remote selection of power factor or VAr fitted in the incoming mains tie with the correct position and
operating modes be required then a single pole changeover phasing. This is usually 'U' phase but local variations may be 'A'
switch (rated at 1A/240V) may be connected to the terminals PF phase, L1 or cables 'red' in colour.
, C and VAR as shown. This will replace the link which is normally
fitted. The use of screened leads is essential with the screen
IF IN DOUBT - REFER TO FACTORY
connected to the adjacent '0V' terminal.

11
9

Fig. 6 Power Factor Control of Individual Generators

10

Fig. 7 Alternative Circuit Breaker Auxiliary Connection

12

Fig. 8 Power Factor Control All Options Fitted

13

Fig. 9 Power Factor Correction of the Incoming Mains Supply

14
 SECTION 4
COMMISSIONING AND ADJUSTMENTS
THERE ARE TWO VERSIONS OF PFC3
PFC3 E000-21030 has BLACK encapsulation
PFC3 E000-22090 is a GREEN board with clear encapsulation
Differences in features and commissioning are referred to where appropriate

To prevent personal injury or damage to Before running the generator, the installing/ commissioning
equipment, only qualified personnel engineer should ensure that all equipment is correctly installed
should install or operate this unit. During and that the generator set is safe to start. They should also have
commissioning the engineer will have studied the section on user adjustable controls and selection
Warning ! access to live components and terminals. links and should have become familiar with their function.
Maximum care should be taken when
making adjustments not to contact live If the generator set controls are normally set to apply load
parts. Refer to the generator and automatically then this feature should be inhibited or switched
switch-gear manufacturers handbooks for to 'manual'.
other safety notices.
Important ! All paralleling operations must be
carried out in compliance with the
The following commissioning procedures generator set designers/ installers
cover ONLY the features of the PFC3. instructions. Newage International
They DO NOT cover such matters as take no responsibility for equipment
electrical installation, phase sequence, damage caused by incorrect
Warning ! switchgear or engine controls. paralleling operations.

Important ! During commissioning of the PFC3 any

Important ! The use of Megger or High Potential connections to terminals RX, RY and
test equipment may result in damage RZ must be removed.
to this unit. Disconnect all leads
before using such equipment. Commissioning of the basic system is best carried out in three
parts:
4.1 Installations
1. Preliminary Adjustments.
ALL Installations: 2. Checking the Droop C/T polarity and setting.
3. Checking of the PFC3 C/T polarity and setting.
- Follow section titled:
4.2 Commissioning Basic System 4.2.1 Preliminary Adjustments

Installations making use of one or more of the optional Before starting the generator set the commissioning engineer
features: should first make sure that the user adjustable controls and
selection links on the PFC3 and certain AVR controls are set as
Follow sections titled: follows.
4.2 Commissioning Basic System and:
4.3 Commissioning Options Note: CW = Clockwise Adjustment
CCW = Counter-Clockwise Adjustment
Installations configured for power factor correction:

Follow sections titled:

4.2 Commissioning Basic System and:
4.4 Power Factor Correction

4.2 Commissioning Basic System

The design of installations involving the paralleling of private

generators with the mains supply will be regulated by the local
generating authority. It is the responsibility of the commissioning
engineer to ensure that the necessary approval has been granted Scaling as shown below
before any paralleling operations are carried out.
AVR controls Droop - Fully CW ( 100% )
The commissioning engineer should also be satisfied that all Trim - Fully CCW ( 0% )
system protection equipment is correctly installed, adjusted and
working and that ALL 'site' safety procedures have been
observed.
15
PFC3 controls PF/VAR - Midway ( 50% ) 4.2.2 Droop Setting
ILIM - Fully CCW ( 0% )
GAIN - Fully CCW n Having checked that the generator is safe to run, the
BAND - Fully CCW set should be started and run up to nominal speed and
XLIM - Fully CCW the AVR volts control adjusted to give an output voltage
equal to that of the installation mains.
Isolate voltage matching transformer if fitted.
n Paralleling of the generator should now be carried out
in accordance with the set/installation designers
instructions. At this stage the commissioning engineer
should take particular notice of the generator output
current.

n If the generator current rises to an abnormally high level

then the generator circuit-breaker should be opened
immediately and the set stopped. In this event it is more
than likely that the droop C/T or its wiring is reversed. If
this is the case then the droop C/T connections to the
AVR should be reversed and the start-up and initial
paralleling procedure repeated. Do not confuse the AVR
droop connections S1/S2 with the PFC3 current
tranformer connections S1/S2.

n After successful paralleling has been achieved, load

should be applied and increased to approximately 50%.
At this point the power factor should still be near unity.
The voltage across terminals S1 and S2 on the AVR
should now be measured (0.5 to 2.5Vac) and recorded
for future reference. The generator output current should
be stable with only minor variations reflecting small
changes in the system (mains) voltage.

n The droop circuit polarity has now been verified and must
The Input Voltage Selection should be made appropriate for the now be set to a level for the best operation of the PFC3.
application (normally line-neutral voltage). Refer to wiring
diagrams supplied with your machine for further details. n Open the generator circuit breaker and stop the set
before proceeding.

The optimum position of the droop control can now be found by

using the following formula:

Potentiometer d
Position ( % ) = X 100%
AVR S1 S2 voltage

Potentiometer 0% = Fully Anti-Clockwise

Position 100% = Fully Clockwise

d = 0.25 for SX440 and MX341 AVRs

d = 1.00 for MX321 and SX421 AVRs

e.g If the measured voltage across S1 and S2 on the SX440 AVR

at half-load was 0.5V, then:

Potentiometer 0.25
Position ( % ) = X 100% = 50%
0.5

The AVR Droop potentiometer should therefore be set to the

midway position.

If the result of this calculation is greater than 100% then it suggests

that the droop C/T ratio is incorrectly rated (or fitted) and the correct
device should be obtained before proceeding further.

The Droop equipment is now set.

16
4.2.3 PFC3 Setting 4.3 Commissioning Options

Having set the AVR droop equipment the PFC3 can now be Before the generator and its PFC3 is put into full operation it will
commissioned as follows. also be necessary to set-up any of the optional features being
installed. The operation of the PFC3 and AVR will have already
Important ! Make sure that the AVR Trim control is been checked during the Commissioning of the basic system.
in the fully counter-clockwise ( 0% )
position. 4.3.1 Voltage Matching Option
n Start the generator, synchronise it with the mains supply
The Voltage Matching Transformer /Isolating Transformer (user
and apply load as described in the section on droop setting.
At this point the power factor should still be near unity. supplied) should be connected as shown in Fig 9. With the system
voltage and frequency at its nominal value, the secondary voltage
(applied to PFC3 terminals L1 and L2) should be nominally
n The 'CB' LED on the PFC3 will indicate that the generator
100Vac to 120Vac. The phasing of this signal is unimportant.
circuit breaker is closed. Check that this is illuminated.

n Check that the voltage matching selection link is set to

n Measure the voltage across terminals S1 an S2 on the
VMAT E000 - 21030 (BLACK) only.
PFC3 (at half-load). This voltage should be between 50-
180mVac. If this is not the case then it suggests that the
PFC3 C/T is incorrectly rated (or fitted) and should be n Turn the AVR Tim control fully anti-clockwise. Start the
replaced by the correct unit before proceeding further. generator and run-up to rated voltage and frequency.
DO NOT PARALLEL.
Note: At this point the generator is under the control of the Set the AVR volts control to give a generator terminal
AVR and droop transformer and the following steps voltage that is in the centre of the expected Mains Utility
simply check the basic functions of the PFC3 before it Supply Voltage variation, e.g. If the expected Supply
is put into full operation. Voltage variation is 380 - 440V then set the generator
terminal voltage to 410 volts.
n Slowly adjust the PF/VAR control on the PFC3 to its fully
anti-clockwise position (maximum lag). If the generator n If the expected Supply Voltage variation exceeds the
current rises to a high level as the adjustment is made, rated generator voltage stated on the nameplate, then
return it to its central position immediately and re-check stop the generator and consult the factory before
that the AVR Trim control is in the fully anti-clockwise proceeding further.
position.
n Stop the generator and turn the AVR Trim control to the
n After a delay of approximately 20 seconds measure the midway position.
voltage appearing across AVR terminals A2 and A1. This
should be between +2Vdc and +5Vdc (meter leads: positive
n Start the generator and run-up to rated voltage and
on A2, negative on A1). If the reading is of opposite polarity
frequency. DO NOT PARALLEL.
(-2Vdc to -5Vdc) then stop the generator and check the
wiring between the PFC3 and the AVR (A1 and A2). If the
wiring is correct then simply reverse the connections S1 n The VMAT LED should be illuminated
and S2 to the PFC3. E000 - 22090 (GREEN) only.

Note: Certain 'third-party' current transformers do not n The PFC3 will now gradually adjust the generator voltage
comply with standard marking conventions. to a new value which could be higher or lower than the bus
voltage. Return the generator voltage to the 'matched'
n Re-start and parallel the generators, apply load and condition by slowly adjusting the BUSV control on the
confirm that the voltage across AVR terminals A2 and PFC3. If the generator volts are 'High' (compared to the
A1 is now of the correct polarity. bus) then the BUSV control should be adjusted slowly anti-
clockwise to equalize the bus and the generator voltages.
n Slowly adjust the PF/VAR control on the PFC3 to its If the generator volts are low then BUSV control should be
fully clockwise position (maximum lead) and measure adjusted clockwise.
the voltage appearing across AVR terminals A2 and
A1. This should be between -2Vdc and -5Vdc (meter Note: The circuit may take several seconds to return the
leads: positive on A2, negative on A1). generator voltage to the 'matched' condition. Due
allowance must be made for this delay whilst making
Stop the generator and turn the PF/VAR control on the PFC3 to adjustments. For best results it is advisable to adjust
the midway position. Turn the Trim control on the AVR to the in small steps and wait for the response.
fully clockwise position.
Stop the generator and turn the AVR Trim control to the fully
The PFC3 is now ready for operation. clockwise position.

The voltage matching option is now set.

17
4.3.2 Current Limiting Option 10. Turn ILIM slowly clockwise. TP2 voltage should reduce in
value. If it rises then stop generator and reverse the S1 S2
Current limiting should only be used when the PFC3 is connected connections to the PFC3 0V and ILIM terminals. Re-
for Power Factor correction of the incoming main feeder. test from line 5.
If the generator has the MX321 AVR and separate current limiting 11. Adjust ILIM until TP2 = Required voltage as calculated
equipment fitted, this should be disabled by turning the ILIM in line 9.
control on the AVR fully CLOCKWISE. 12. Stop the generator and remove the generator CT
The Current Limiting Transformer should be connected as shown connections S1 S2 on the PFC3 and terminate the
generator CT wires with a suitable shorting link.
in Fig 8 (feature 3). The phasing of this C/T is important.
13. Connect the mains feeder CT S1 / S2 cables to the
For power factor correction applications it is usual to have two PFC3 (observing polarity) and remove the mains
current transformers (C/T's) fitted in the generator terminal box, feeder CT shorting link.
one with a 5 Amp secondary and one with a 330 mA secondary.
There will also be a 5 Amp secondary CT fitted to the Mains 14. Turn the PFC3 PF / VAR setting potentiometer to the
Utility incoming feeder. centre position.

The 5 Amp Generator mounted CT is used for normal 15. Start the generator and parallel to the mains network.
Commissioning and Generator Power Factor Control. This will 16. Set the generator to the required operating kW.
be unused in Power Factor Correction operation and provision
should be made for connection of a shorting link to prevent an 17. Adjust the desired mains power factor using the PF /
open CT secondary. VAR setting potentiometer on the PFC3.

The 330mA Generator mounted CT is used for measuring 18. Set-up is now complete.
generator reactive current for the I Limit feature. 4.3.3 Low Excitation Limiting Option
Low Excitation Limiting should only be used when the generator
The 5 Amp CT connected to the Mains Utility incoming feeder is is to be operated at leading power factor.
the one used in service for Power Factor correction. This CT
could be carrying site current and provision should be made for The Excitation Limiting input ( X and XX ) should be connected
the connection of a shorting link to prevent an open CT secondary. in parallel with the generator exciter field winding as shown, in
Fig 8 (feature 4). The two exciter field connections ( X and XX )
1. With the generator stationary connect the generator will normally be found at the auxiliary terminal block within the
mounted 5 Amp CT to the PFC3 S1 S2 terminals, generator. If these terminals do not exist, a suitable connection
observing polarity. Generator wiring diagrams will show block can be obtained from Newage International.
the full details.
Connect a digital multimeter as follows:
2. Connect the Generator mounted 330mA I Limit CT Negative Input to 0V (any of four) on the PFC3
to the PFC3 connections 0V / ILIM, S1 to ILIM, S2 Positive Input to Test Point TP4 on the PFC3
to 0V. Generator wiring diagrams will show the full Set to measure on the 20Vdc scale
details.
n Set the voltage matching selection link to NORM.
3. Turn the PFC ILIM potentiometer fully anti-clockwise.
n Start the generator and run-up to rated voltage and
4. Set PF / VAR selector to PF. frequency. DO NOT PARALLEL.
5. Parallel generator to mains network and run at maximum n Using the graph shown in Fig 11, adjust the low excitation
kW set-point rating. limit control XLIM to set the voltage on the test point as
indicated.
6. Adjust the PFC3 to give a generator PF of 0.9 lagging.
n Stop the generator and set the voltage matching selection
7. Calculate the operating Per Unit Reactive Current (PURC) link to its original position.
against generator rating :-
The low excitation limiting option is now set.

Fig. 10
8. Measure TP2 voltage between 0V and TP2, meter neg (-)
on OV. This should be between +2 and +4V dc. For the
location of TP2, see the label drawing on the PFC3 access
cover plate or PFC3 manual.

9. Calculate required setting of TP2 voltage :-

[ (1 - PURC) X (TP2 voltage + 0.3) ] - 0.3 Fig. 11 Low Excitation Limit Setting

18
4.3.4 Dead-Band and Dynamic Control Options leading power factor must be treated with care. Operating the
generator at leading power factor will cause the excitation to be
reduced to a level where loss of synchronisation may occur. This
For the majority of applications, dynamic control is recommended
may cause protective equipment to operate and the loss of the
as this is the more accurate and has the fastest response time of
correcting influence of the generator or, in extreme cases,
the two operating modes. However, if instability is encountered,
equipment damage.
then dead-band control may provide the necessary flexibility
within the generator control loop to overcome this undesirable
effect. Where these conditions are likely to exist it is recommended that
the Low Excitation Limiting option be used (see section 4.3.3).
In dynamic mode, correction signals are continually fed to the
AVR in order to maintain the set power factor. In dead-band Use of Excitation Loss equipment is also strongly recommended
control, the power factor is allowed to 'drift' within preset limits for all installations where industrial ac generators run in parallel
before any corrective action is taken. Allowing the loop to 'open' with the mains supply (see section 3.2).
in this way provides for a less accurate control but much improved
stability.

In dead-band control mode the correction signals take the form

of pulses which change in width as the error (deviation from set-
point) changes.

The three controls which alter the overall performance of the

PFC3 in dead-band mode are as follows:

[ BAND ] Adjusts the Dead-band width in dead-band mode

and allows the PF (or VAr) to drift between wider
limits before AVR set-point adjustments are made.

[ CLK ] Sets the rate at which AVR adjustments are made

(in dead-band mode only).

[ GAIN ] Makes the controller more or less sensitive to

deviation from the set-point (in dead-band mode
only) by altering the size of each adjustment.

For more information on the above adjustments see the section

on User Adjustable Controls and Selection Links.

If dead-band mode is selected it is strongly recommended that

the Gain and Band are set fully counter-clockwise (lowest gain,
widest band). These controls can then be adjusted from their
initial positions by trial and error to find the optimum setting.

As an aid to setting, red light emmitting diodes (LEDS) indicate

increase (INC) and decrease (DEC) excitation signals. The clock
(CLK) indicates the rate of error correction signals and is preset
at the factory at approximately one per second.

4.4 Power Factor Correction

With the generator operated as a power factor correction system

it will be possible to overload the generator windings with a PFC3
setting of near unity power factor WITHOUT overloading the
engine/prime-mover. In this situation the generator has to supply
the necessary reactive current to the load in order to correct the
mains supply power factor to that set on the PFC3. The generator
output current is therefore independent of the governor setting
(kW) and/or the power factor setting on the PFC3.

Before the generator is put into operation in this mode the Current
Limiting option MUST be installed and commissioned (see section
4.3.2).

The commissioning engineer should also attempt to establish

the nature of the site load. Since the generator will be expected
to supply all or part of the reactive component of load current,
any condition which would result in the generator operating at
19
 SECTION 5
USER ADJUSTABLE CONTROLS AND SELECTION LINKS
Refer to Figs 12 and 13 for the location of adjustments and [ BUSV ] When this option is wired/enabled, adjusts the
selection links. relative proportion of bus volts applied to the main
comparator/amplifier to make allowances for
Important ! Any control marked with an 'R' different user supplied isolation transformers.
followed by a number is NOT a user
adjustable control. Do NOT adjust CW = Increases generator voltage
unless instructed by Newage CCW = Decreases generator voltage
International to do so.
[ XLIM ] When this option is wired/enabled, adjusts the
Important ! Make sure you fully understand the lowest level of excitation permissable when
function of each control and link operating at leading power factor.
before making any adjustments.
CW = Raises the low excitation limit
Note: CW = Clockwise Adjustment
CCW = Lowers the low excitation limit
CCW = Counter-Clockwise Adjustment
The remaining controls are set and sealed at the factory:
[PF/VAR] Is the main Power Factor or Reactive Current setting
control dependent upon which mode of operation
the PFC3 is selected for. TP1 - TP6 are used for special setting up procedures.

PF mode CCW = Lag 5.1 Light Emitting Diode (led) Indicators

Midway = Unity Power Factor
CW = Lead ( CB ) Indicates closure of terminals CB1 and CB2 and
that the PFC3 is operating in power factor (or VAr)
mode.
VAr modeCCW = Export (generate) VAr
Midway = Minimum VAr
(VMAT) To indicate presence of voltage matching signal.
CW = Import (absorb) VAr
E000 - 22090 (GREEN)

[ STAB ] Adjusts the effective 'damping' within the PFC3

( CLK ) To indicate the rate of correction signals when
operating in dead-band mode.
CW = Fully damped (most stable)
CCW = Minimum damping ( INC ) To indicate when the PFC3 is increasing the AVR
set-point in dead-band mode.
[ BAND ] Adjusts the Dead-band width in dead-band mode
and allows the PF (or VAr) to drift between wider ( DEC ) To indicate when the PFC3 is decreasing the AVR
limits before AVR set-point adjustments are made. set-point in dead-band mode.

CW = Narrow Band
5.2 Selection Links & Switches
CCW = Wide Band
{ PF - C - VAR } Power Factor or VAr modes
[ CLK ] Sets the rate at which AVR adjustments are made
(in dead-band mode only).
{ NORM - C - VMAT } Normal or Voltage Matching modes
E000 - 21030 (BLACK)
CW = Faster Rate
CCW = Slower Rate
{ 1 = DYN 2 = DBD } Dead-Band or Dynamic modes
E000 - 22090 (GREEN)
[ GAIN ] Makes the controller more or less sensitive to
deviation from the set-point (in dead-band mode
only) by altering the size of each adjustment. { DBD - C - DYN } Dead-Band or Dynamic modes
E000 - 21030 (BLACK)
CW = Large Adjustments made
CCW = Small Adjustments made { C - 220 - 240 - 277 } Input Voltage Selection
E000 - 21030 (BLACK)
[ ILIM ] When this option is wired/enabled, adjusts the level
at which generator current limiting takes place. { 115 - C - 220 -
240 - C -277 } Input Voltage Selection
CW = Decreases the current level E000 - 22090 (GREEN)
CCW = Increases the current level

20
Fig. 12 PFC3 User Adjustable Controls and Selection Links
Part number E000 - 21030 (BLACK)

Fig. 13 PFC3 User Adjustable Controls and Selection Links

Part number E000 - 22090 (GREEN)

21
 SECTION 6
OPERATION
6.1 General 6.6 Overvoltage

Important ! Before putting the generator into full If at any time during generator operation, the terminal voltage
operation the Trim control on the AVR exceeds the rated generator voltage stated on the nameplate,
MUST be set to the fully clockwise position. then stop the generator and consult the factory.

Under normal circumstances the operation of the PFC3 is fully

automatic and once commissioned the unit should continue to
operate without further attention.

Once commissioning is complete it will only be necessary to set

the operational power factor on the PF/VAR control on the PFC3.
The actual operating point of the power factor controller will be
determined by the application and the following notes are for
guidance only.

6.2 Combined Heat And Power Installations

Installations where the generator is operated at a kW rating

dependent upon the 'heat' demand from the site.

Normal PFC3 setting would be 1.0pf to 0.8pf lag to optimise the

utilisation of the generator rating but care must be taken not to
export unacceptable levels of VAr to the mains supply.

6.3 Peak Lopping Installations

Installations where the generator is used to supply all the site

load in excess of a maximum set by the mains provider.

Normally the PFC3 would be set to generate at a power factor

equal to the site load average and at a fixed power level
(maximum rating of the set) in order to reduce the incoming
demand on the mains to a minimum.

6.4 Power Factor Correction

The generator is used to provide the site VAr necessary to

maintain the power factor of the incoming mains supply within
fixed limits.

Normal PFC3 setting would be 1.0pf to 0.8pf lag to optimise the

power factor of the incoming supply, care must be taken that the
generator rating is not exceeded. The current limiting feature of
the PFC3 MUST be used in this situation.

6.5 Synchronous Motors

Using an a.c generator as a synchronous motor will demand a

setting of 1.0pf to 0.9pf on the PFC3.

Important ! Users of ac generators as

synchronous motors must provide the
necessary equipment and/or
procedure for starting e.g pony motor.

When using an ac generator (equipped with a PFC3) as a

synchronous motor, the wiring required is identical to that of
generator applications. There is NO requirement to reverse C/T
or any other phase sensitive connections.
22
 SECTION 7
TROUBLE SHOOTING

Under normal circumstances the operation of the PFC3 is fully n The reactive power output (kVAr) of the set is controlled
automatic and once commissioned the unit should continue to entirely by the excitation system of the generator (i.e
operate without further attention. Should the system fail in service, the AVR). Problems concerning reactive current
the trouble shooting chart shown in Fig 14 will be helpful in (circulation/ fluctuation etc.) are almost certainly to do with
identifying the cause. the generator AVR and its associated equipment.

Mains Utility Supply Voltage Variations Spares & Service

In some areas, large voltage variations can take place causing A full technical advice and on-site service facility is available
malfunction of the generator control system. from our Service Department at Stamford or through our
subsidiary Companies.
As stated in section 3.2, it is the responsability of the Generating
Set Assembler to install adequate protection to safeguard the When ordering parts the machine Serial Number or Machine
generator. Identity Number and type should be quoted, together with the
part description. The Serial Number is printed on the nameplate
If satisfactory operation cannot be achieved then is would be and the Machine Identity Number on two labels inside the
advisable to carry out a Mains Utility Supply Voltage survey over terminal box.
a minimum period of 24 hours, recording the absolute maximum
and minimum RMS voltages and also the largest step change. Orders and enquiries for parts should be addressed to:
Consult the factory for advice.
Newage International Ltd.,
The user is reminded of the following information relating to the Nupart Department,
paralleling of generators. P O Box 17, Barnack Road,
Stamford, Lincolnshire
n The active power output (kW) of the set is controlled entirely
by the engine governor and NOT by the generator AVR. PE9 2NB, England.
Problems concerning kW fluctuations etc. are almost Telephone: 44 (0) 1780 484000
certainly to do with the engine fuel system and/or frequency Cables Newage Stamford
control. Telex: 32268
Fax: 44 (0) 1780 766074
or any of our subsidiary companies listed on the back cover.

Fig. 14 PFC3 Fault Finding Chart

23
 SECTION 8
TECHNICAL SPECIFICATION
Input voltage (50-60Hz) 115 range 110-125v ac Applies to PFC E000 - 22090 (GREEN)
220 range 200-230v ac 5VA
240 range 231-250v ac
277 range 251-290v ac (60 Hz only)

Input current PF/VAR sensing 5A CT 2.5VA

Current Limit 330mA CT 2.5VA

Voltage matching input 110v ac ± 10%

5 vA nominal

Low excitation limit input 150 V dc Max

AVR control range (A1 A2) ± 3 volts dc

Power Factor setting range (PF) 0.7 lag to 0.7 lead (see note 1)

Remote PF setting potentiometer value 10K ohms 1 watt

Reactive current setting range (VAR) generate/absorb 0-100% gen. current (see note 1)

Low excitation limit range 2-8 volts dc

Current limit range 70-100% gen. current

Control accuracy VAR ± 5% (see note 2)

Power Factor ± 0.05 pf
Voltage matching ± 2%

Reponse time constant 4 seconds

Generator output voltage limiting range ± 5% to ± 15%

Environmental Vibration 20-100 Hz 50 mm/s

100-2 kHz 3.3 g
Relative humidity 0-60 °C 95%
Operating temperature -40 to +70 °C
Storage temperature -55 to +80 °C

Note 1: Refer to generator lag/lead performance data sheets for

permissible operating conditions.

Note 2: Control accuracy may drift if the CT secondary current falls below 0.5 Amps.

24
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REGISTERED OFFICE AND ADDRESS:
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LINCOLNSHIRE
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