P OW E R S E R I E S C O N T RO L L E R S

Microprocessor-Based
SCR Power Controller
Designed for
Application Flexibility

Watlow has manufactured solid state power controllers for Features and Benefits
over thirty years. Watlow’s POWER SERIES represents the
latest in SCR power controller technology. This microproces- Microprocessor-based technology
sor-based product offers features and application flexibility • Extremely versatile and field configurable
unmatched by any other SCR power controller on the market Snap-fit on a pre-mounted plate
today. • Simplifies installation
Capabilities of Watlow’s POWER SERIES controllers include Models 65 through 250 amp ratings
single-phase and three-phase models from 65 to 250 amps. • Handles a wide range of loads
Field configurable phase angle or zero cross firing improves
application flexibility on site where you need it.The 50/60Hz Adjustable soft start
independent operation allows utilization almost everywhere • Provides application flexibility
in the world without special calibration considerations. Serial Heater and control diagnostics capability
communication utilizing Modbus™ protocol provides remote • Monitors actual heater and controller performance
control setup and monitoring of load status from a nearby
computer station or control room. Electrically touch-safe package
• Enhances safety for installer and users
On-board semiconductor fusing improves reliability by
protecting the SCRs from heater short circuits. Plus, Serial communications with Modbus ™ RTU protocol
on-board heater bakeout and control diagnostics can help • Provides computer control and/or monitoring
eliminate initial start up problems. All these benefits are in a Multizone capability
touch-safe package that can be quickly and easily mounted • Increases application flexibility and reduces panel space
in your control cabinet.
Watlow’s POWER SERIES controllers are UL® and C-UL®
recognized, so users can be assured that the controllers
meet world safety and operational standards.

UL® and C-UL ® are registered trademarks of the Underwriter’s Laboratories, Inc.
Modbus™ is a trademark of Schneider Automation Inc.

WIN-PS-0403
1241 Bundy Boulevard
Winona, Minnesota 55987-5580 USA
Phone: 507-454-5300
Fax: 507-452-4507
Internet: www.watlow.com
e-mail: info@watlow.com

© 2003 Watlow Electric Manufacturing Company Printed in the USA on Recycled Paper, 15% Postconsumer Waste
Specifications • Calibration accuracy:
Power Bases mA ranges = ±20µA
• Single phase, (2 SCRs) VÎ(dc) ranges = 10mV nominal
• 3 phase, 2 leg control, (4 SCRs) • Temperature stability: 100ppm°C
Resistive load only, zero cross firing only Digital Programmer/Display and Communications
• 3 phase, 3 leg control, (6 SCRs) Capabilities
• 3 phase, 3 leg control, (6 SCRs) for 4-wire wye loads • Programming functions
• Multizone, two and three single-phase zones • Adjust input and output control type, alarms and soft start,
Output Control Options heater bakeout and current limit prompts
• Zero cross contactor, VÎ(dc) input • Monitoring functions
• Zero cross control, fixed time base • Display input and output values along with actual
• Time base one or four seconds with digital programmer output current
• Zero cross control, variable time base • Data retention of digital prog rammer/display upon power failure
• Phase angle control and phase angle control with current limit via nonvolatile memory
(not for 3-phase, 2-leg models) Serial Communications
• Soft start factory default four seconds upon power-up, and • RS-232 for single drop control
adjustable from 0.0 to 120 seconds • EIA-485 for single or multidrop control
• Soft start upon input signal change, output rate of change • 32 units maximum can be connected.With additional
adjustable to limit max rate of change from 0.1 to 100 percent 485 repeater hardware, up to 247 units may be connected
per 0.1 second. Factory default 10 percent • Isolated
• Current transformer included when required • Modbus™ RTU protocol
• Line voltage compensated (variable time base and phase angle • 1200, 2400, 4800, 9600, 19200 baud rates
controllers only) Controller Power Supply
• Standby or non-operational mode • Universal line voltage input range 100 to 240VÅ(ac)
Output Voltage and Current Rating (+10 percent, -15 percent) at 55VA max
• 24 to 120VÅ(ac) (+10 percent, -15 percent) • 50/60Hz ± 5 percent line frequency independent
• 200 to 480VÅ(ac) (+10 percent, -15 percent) • Controller line voltage for electronic power supply can be run
• 200 to 600VÅ(ac) (+10 percent, -15 percent) on separate line voltage
• 65 through 250 amps per pole, model dependent; see Output Natural Convection and Fan Cooled Models
Amperage Chart and Rating Curves • Cabinet venting may be required
• Minimum load 1 amp rms ac • See Amperage chart on the back page for all models.
• Maximum leakage current 5mA Power Dissipation (Watts)
Alarms • Approximately 1.25 watts/amp per controlled leg
• Single alarm relay Isolation
• Latching or non-latching • Command signal to load and line/load to ground
• Separate high and low values 2200VÅ(ac) minimum
• Alarm silencing (inhibit) on po wer up for alarm • On-board semiconductor fuses provide SCR protection
• Alarm indication LEDs, shorted SCR, open heater, fuse Mounting
• Electromechanical relay, form C contact, software • Mounts on a removable subplate
configurable • Heat sink fins must be mounted in vertical orientation
• Minimum load current 10mA @ 5VÎ(dc) High Current Terminals
• Rated resistive loads: 3 amps @ 250VÅ(ac) or 30VÎ(dc) • Touch safe
max., inductive load rating 1.5 amps with a power factor • 10 mm ( 3⁄8 in.) Allen head compression terminals will accept
≥ 0.4 without contact suppression #6 AWG to 350 MCM wire. Allen wrench adapter (included) for
Heater Bakeout 10 mm ( 3⁄8 in.) socket, 6 point only
• For single-phase (phase to neutral) and 3-phase 6 SCR • Torque to 180 in.-lbs (20.3 Nm)
models only (not for 3-phase, 2-leg models) • Wire strip to 30 mm (11⁄8 in.)
• Soft start with over current trip, runs until programmed bakeout Controller Terminals
time expires, then goes burst or phase angle firing. Factory • Touch safe
default of 24 hours • 2.5 mm ( 1⁄8 in.) blade screwdriver, accepts 12-22 AWG or
• Adjustable 0 - 9999 minutes with over current trip 2 No. 22-18 AWG wires
• Internal current transformer included • Torque to 8 in.-lbs (0.9 Nm)
Command Signal Input • Wire strip to 6 mm (0.24 in.)
Analog Operating Environment
• Field selectable linear voltage and current of low and high • 50°C (122°F) base rating
points within 0-20mA and 0-10V Î(dc) • 0 to 60°C (32 to 140°F) fan cooled
• Manual control input through front panel • 0 to 65°C (32 to 149°F) natural convection cooled
• Factory default 4-20mA input • 0 to 90 percent RH, non-condensing
• Voltage input impedance 11kW nominal • Meets EN50178, Pollution degree three
• Current input impedance 100W nominal Storage Temperature
Digital • -40 to 85°C (-40 to 185°F)
• On-board digital programmer/display and optional serial Shipping Weight
communications • 10.3 kg (23 lbs)
Retransmit Agency Approvals
• Field selectable and scalable within 0-20mA, • UL® 508 listed, File #E73741, Vol. three, Sec.two
800W maximum or 0-10VÎ(dc), load, 1KW minimum load. • C-UL® listed to C22.2 NO. 14
The default is 4-20mA • VDE EN 50178 License 115054
• Resolution: • CE 89/336/EEC (EN61326), Class A with filter,
mA ranges = ±5µA CE 73/23/EEC (EN50178)
VÎ(dc) = ranges 2.5mV nominal

Modbus™ is a trademark of Schneider Automation, Inc.

Package Style C Dimensions Mounting Plate Dimensions
POWER SERIES Front View Release Tab

Mounting Holes (4)

7 mm
(0.27 in.)

354 mm
(14.0 in.)

Key Slots 178 mm

(7.00 in.)

POWER SERIES Top View

102 mm 25 mm 39 mm
(4.00 in.) (0.97 in.) (1.53 in.)
151 mm
200 mm (5.93 in.)
(7.9 in.)

191 mm
(7.5 in.)

POWER SERIES Features

 Single Phase Configuration
Ordering Information This configuration can be purchased with any or all the
features available on the POWER SERIES, based on
POWER SERIES PC__ - ____ -____ customer preference. It is intended for resistive heaters,
Microprocessor-based, but can also be used on transformer connected loads in
solid state power controller the phase angle firing mode.
Package Style Three-Phase, Two Leg Configuration
C = 65 to 250 amps This configuration is intended for zero cross firing only into
Phase a stable resistive heater. Typically, a three-phase delta or
1 = 1 phase ungrounded wye connected heater is used and only two of
2 = 3-phase/2-leg control, (4 SCRs) the three V~ line phases are switched.The third phase
3 = 3-phase/3-leg control, (6 SCRs) is a direct connection through a bussbar on board the
POWER SERIES. Heater current monitoring and kVA options
4 = 3-phase/4-wire, wye
are available via the heater diagnostics option.
connected load
8 = 2 single-phase zones Three-Phase, Three Leg Configuration
9 = 3 single-phase zones All POWER SERIES options are available with this
configuration. It works well with phase angle firing into a
Heater Diagnostics three-phase, three-wire wye or delta connected heater. In this
0 = None configuration, the more common applications are transformer
1 = Heater diagnostics (required for any connected loads with heaters requiring a soft start and/or
heater current monitoring or current current limiting.
limiting).
The three-phase, four-wire configuration is intended for zero
Output Amperage Rating cross firing into a three-phase grounded wye/star heater (This
(See amperage chart to the right) is a separate hardware option, model number dependent.)
Output Voltage Rating Single-Phase, Multizone Configuration
A = 24 to 120V This configuration is available in two and three single-phase
B = 200 to 480V zones and all the features of a single-phase unit are
C = 200 to 600V available. (Note that there is only one alarm relay and all
Communications zones in the controller must use the same control method.)
0 = None Heater Diagnostics
1 = EIA/TIA-232/485 communications, Heater diagnostics may include some or all of the
opto-isolated (field selectable) features that require heater current monitoring, depending
on the model selected. Heater current monitoring is only
Feedback/Retransmit available with heater diagnostics installed on the controller.
0 = None The features dependent on heater current monitoring are
1 = Load current feedback (0-10V or 0-20mA scalable heater bakeout, current limiting, heater kVA monitoring,
retransmit output) (Must have heater retransmit and heater monitoring alarms such as open heater,
diagnostics selected) heater out of tolerance, load balance and shorted SCR
Custom detection/error. Heater diagnostics must also be installed
00 = None if you need phase angle control with current limit.
AA = No Watlow logo with agency approval marks
XX = Custom, consult factory for options Amperage Chart— 50˚C (122˚F)
Non-Fan Cooled
2 Zone and 3 Zone and
Single Phase 3 Phase, 2 Leg 3 Phase, 3 Leg
Your Authorized Watlow Distributor Is: Code Amperage Code Amperage Code Amperage
N20 100A N20 80A N20 65A
N25 140A N25 105A N25 85A
N30 165A N30 120A N30 105A

Fan Cooled
Single Phase 3 Phase, 2 Leg 3 Phase, 3 Leg
Code Amperage Code Amperage Code Amperage
F20 125A F20 120A F20 90A
F25 200A F25 160A F25 140A
F30 250A F30 185A F30 155A

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