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The QPAC modular controller 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 configurations.

A variety of transformers from 120 to 575VAC, along with 50/60Hz operation, enable the QPAC modular controller 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 and are available with a wide variety of options. High speed fuses are included to protect the SCR modular controller from short circuit currents. 200KA short circuit current rating (SCCR) prevents arc flash.


Mounting:  Back panel
Max Output:  1000A
Output Firing:  Zero Cross, Phase Angle
Phase Configurations:  1 or 3
Ambient Operating Range:  0 to 50°C  (32 to 122°F)
Agency Approvals:  UL®, C-UL®, SCCR
Dimensions:  13 in. (330 mm) H x 6.9 in. (175 mm) W x 10.25 in. (260 mm) D
Warranty (years):  3
Note: The specifications in the table above are best available values in each category. Not all combinations of these values are available in a single model number.

Features & Benefits:

Features Benefits
200KA short circuit current rating (SCCR)
  • Prevents arc flash
Modular power controller
  • Offers a variety of plug-in transformers and controller cards
Available in 150 to 1000 ampere ratings
  • Handles large or medium size 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
  • Can be used in industrial applications with full rating of the power controller
Semiconductor fuses and snubber protection included
  • Protects the SCR from voltage or current surges or spikes
Open heater or shorted SCR detector option
  • Performs diagnostics
UL® 508 listed and C-UL® up to 1000 amperes
  • Meets applications requiring agency approvals

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Related Literature

Specification Sheets (3)

Brochures (2)

User Manuals (3)

Training and Education (4)

White Papers (2)

Quality Certificates (1)

Agency Approvals (1)

Catalogs (2)