Snow melting kit 3ft. X 20ft., 240V, control and relay

Electric-resistance heating cables and systems have no polarity. This includes all current WarmlyYours heating elements.

Power requirements are measured in Amps and based on three factors: the watts per sq. ft. of the snow melting cable or mat, the area powered and the voltage used for the application. Our PowerMat product is rated at approximately 50 watts per sq. ft. (with 3" cable spacing), so that is a constant factor. Most snowmelt projects are powered with 240V AC – not all, but most. The one factor that is always variable is the area to be heated/powered. That is based on your project. For a point of reference, let's use the example of a 350 sq. ft. concrete patio.

The formula is (50 W/sq. ft. x area of 350 sq. ft.) / V (240V) = Amps, so 17,500 / 240V = 72.9 Amps

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.