Watlow QPAC Power Controller

up to 1000 amps
Watlow QPAC Power Controller
The QPAC SERIES from Watlow® is a modular Silicon Controlled Rectifier (SCR) power controller with plug-in features for flexibility. Bases are rated from 150 to 1000 amperes in one-phase, three-phase, two leg and three-phase, three leg.

A variety of transformers from 120 to 575VAC along with 50/60Hz operation enable the QPAC to operate in applications anywhere. Plug-in control cards set the QPAC’s SCR firing modes; solid state contactor, burst firing (zero cross) or phase-angle models are available with a wide variety of options. This power controller includes 200KA short circuit current rating (SCCR) and high speed fuses to minimize damage in the event of a short circuit.
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Product Features

200KA short circuit current rating (SCCR)
  • Minimizes damage in the event of a short circuit
Modular power controller
  • Unit base can be fitted with a variety of plug-in transformers and control cards
Available in 150 to 1000 ampere ratings
  • Handles large or small loads
Available in solid state contactor, burst firing (zero cross) or phase-angle fired mode
  • Meets most application requirements
Rugged design for 122°F (50°C) ambient operation
  • Full rating of the power controller can be used in industrial applications
Semiconductor fuses and snubber protection included
  • Protects the SCR from voltage or current surges or spikes
Open heater or shorted SCR detector option
  • Diagnostic capabilities
UL® 508 listed and C-UL® up to 1000 amperes
  • For applications requiring agency approvals

Product Specifications

Operation Modular controller base with plug-in card and transformer:
  • Plug-in control cards
  • Solid state contactor, dc input
  • Burst fire control, fixed or variable time base
  • Phase-angle fire control
  • Phase-angle control with soft start and current limiting
  • Plug-in transformers (50/60Hz)
  • 120, 208, 240, 380, 415, 480, 575VAC operation
Power bases:
  • 1-phase (Q01), 1 pair of SCRs
  • 3-phase (Q32), 2 leg control, 2 pair SCRs
  • Resistive load only, burst firing only
  • 3-phase (Q33), 3 pair hybrid SCRs/diodes
  • Recommended for phase-angle only with balanced load
Agency Approvals:
  • UL® 508 and C-UL® listed, 150 to 300A all configurations, File #E73741
  • UL® 508 and C-UL® listed, 400 to 1,000A on Q01 and Q32, up to 480VAC
Control Card Inputs:
  • (CD) Solid state contactor, dc input
  • On, 4-32VDC; off, 0.5VDC
  • Built-in noise reduction network
  • (BF) Burst firing control fixed time base
  • Process input factory set @ 4-20mA DC
  • Input impedance 250Ω (clip resistor for 5kΩ impedance voltage input), or manual control input
  • Time base 4 seconds (clip resistor for 1 sec)
  • (BV) Burst firing control, variable time base
  • Process input factory set @ 4-20mA DC
  • Input impedance 250Ω (clip resistor for 5kΩ impedance voltage input), or manual control input. Requires an accessory bias and gain card to calibrate for 0-5VDC input
  • (AF) Phase-angle control
  • Process input factory set @ 4-20mA DC
  • Input impedance 250Ω (clip resistor for 5kΩ impedance voltage input), or manual control input
  • Soft start approximately 6 seconds upon power-up, 1 second upon set point change
  • (AL) Phase-angle control with current limit
  • Process input factory set @ 4-20mA DC
  • Input impedance 250Ω (clip resistor for 5kΩ impedance voltage input), or manual control input
  • Soft start approximately 10 seconds upon power-up, 1 to 2 seconds upon set point change
  • Current transformer included
Open Heater/Shorted SCR Detector:
  • Zero cross/burst fire models only
  • Triac output
  • 24 to 240VAC, 300mA @ 77°F (25°C), 125mA @ 176°F (80°C)
  • Energizes on alarm
  • Holding current 200μA min.
  • Latching current 5mA typical
Outputs:
  • 120 through 575VAC
  • 1, 2 or 3 pole
  • 150 to 1000A per pole
  • SCCR, 200KA with original equipment specified semiconductor fusing
Line Voltage / Power:
  • 50/60Hz ac line frequency, Q32 and Q33 models are 50/60Hz calibration dependent
  • Voltage: ±10%, 120, 208, 240, 277, 380, 415, 480, 575VAC
Line Voltage Compensation:
10% Δ in line, 2% Δ in load in the 30 to 70% power region (AF, AL and BV)
Power Dissipation (Watts):
1.5 W/A per controlled leg
Isolation:
Command signal to load 1250VAC min.
Linearity:
2%, 30 to 70% power region (All units except CD)
Off-State Leakage Current:
20mA @ 480VAC
SCR Protection:
  • Semiconductor fuses provided dv/dt 200V/μsec min.
  • MOV1 and RC snubber network standard
  • (Q32) 3rd leg fuse kit may be used, but not required, with 3-phase, 2 leg models
Mounting:
Heat sink fins must be mounted in vertical orientation
Operating Environment:
  • 32 to 122°F (0 to 50°C)
  • 0 to 90% RH, non-condensing
  • 2,000 meters altitude
Storage Temperature:
-40 to 185°F (-40 to 85°C)
Options:
  • Manual Control Kit for process input cards (1kΩ potentiometer) #08-5362
  • 240VAC and 120VAC cooling fans

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