Waterproof Outdoor Thermostat for Pipe Freeze Protection or Roof and Gutter Deicing Systems

GFEP is the National Electric Code (NEC) required protection for fixed outdoor deicing and snow-melting equipment, which may be accomplished by using circuit breakers equipped with ground-fault equipment protection (GFEP) of 30 mA. It is important to understand that this required equipment protection is NOT the same as a 5 mA GFCI used for personal protection.

A 2 pole single-phase 240V circuit works by continuously monitoring the current flowing through both hot wires of the circuit. If it detects even a slight imbalance between the current on each hot wire (indicating a ground fault), it will quickly trip, cutting off power to the circuit. Essentially, it compares each leg of the 240V circuit and trips if they are not precisely equal.