No, using external contactors will cause the GFEP circuit on the APS-4C to detect the inductive load of the contactors coil as ground fault and alarm the system every time the contactor is turned on. In order to increase the size of the application, a SC-40C satellite control can be used with the APS-4C without triggering the ground fault protection.

The APS-3C is designed without an internal GREP circuit so it will work with external contactors or direct heater loads. In both of these applications you must provide a GFEP breaker to power the heater circuit.

Click here to view the APS-C series manual

APS-4C and SC-40C without external contactors