Starting at $2,252.00
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  • Microprocessor-based technology - versatile and field configurable
  • Snap-fit on a pre-mounted plate simplifies installation
  • Models 65 through 250 amp ratings handle a wide range of loads
  • Adjustable soft start provides application flexibility
  • Monitors actual heater and controller performance - Heater and control diagnostics
  • Electrically touch-safe package enhances safety
  • Serial communications with Modbus RTU protocol
  • Multizone capability increases application flexibility and reduces panel space


Capabilities of Watlow Power Series controllers include single-phase and three-phase models from 65 to 250 amps. Field configurable phase angle or zero cross firing improves application flexibility on site where you need it. The 50/60Hz independent operation of the Watlow Power Series controllers allows utilization almost everywhere in the world without special calibration considerations. Serial communication utilizing Modbus ™ protocol provides remote control setup of the Watlow Power Series controller and monitoring of load status from a nearby computer station or control room.

The Watlow Power Series controller features on-board semiconductor fusing which improves reliability by protecting the SCRs from heater short circuits. Plus, on-board heater bakeout and control diagnostics can help eliminate initial start up problems. All these benefits of the Watlow Power Series controller are in a touch-safe package that can be quickly and easily mounted in your control cabinet.

Watlow Power Series controllers are UL ® and C-UL ® recognized, so users can be assured that the controllers meet world safety and operational standards.

Applications for the Watlow Power Series Controllers

  • Semiconductor processing
  • Plastics processing
  • Heat treating
  • Drying ovens
  • Food Processing
  • Petroleum/chemical
  • Lighting equipment
  • Furnace/oven
Single Phase Configuration

This configuration can be purchased with any or all the features available on the Watlow Power Series controller, based on customer preference. It is intended for resistive heaters but can also be used on transformer connected loads in the phase angle firing mode.

Three Phase, Two Leg Configuration

This configuration is intended for zero cross firing only into a stable resistive heater. Typically, a three-phase delta or ungrounded wye connected heater is used and only two of the three V~ line phases are switched. The third phase is a direct connection through a bussbar on board the Watlow Power Series controller. Heater current monitoring and kVA options are available via the heater diagnostics option.

Three Phase, Three Leg Configuration

All Watlow Power Series controller options are available with this configuration. It works well with phase angle firing into a three-phase, three-wire wye or delta connected heater. In this configuration, the more common applications are transformer connected loads with heaters requiring a soft start and/or current limiting. The three-phase, four-wire configuration is intended for zero cross firing into a three-phase grounded wye/star heater. This is a separate hardware option, model number dependent.

Single Phase, Multizone Configuration

This configuration is available in two and three single-phase zones and all the features of a single-phase unit are available. Note that there is only one alarm relay and all zones in the Watlow Power Series controller must use the same control method.

Heater Diagnostics

Heater diagnostics may include some or all of the features that require heater current monitoring, depending on the model selected. Heater current monitoring, depending on the model selected. Heater current monitoring is only available with heater diagnostics installed on the controller. The features dependent on heater current monitoring are heater bakeout, current limiting, heater kVA monitoring, retransmit and heater monitoring alarms such as open heater, heater out of tolerance, load balance and shorted SCR detection/error. Heater diagnostics must also be installed if you need phase angle control with current limit.