Protective circuit for electrical heating element

摘要

The present invention provides an electrical circuit that measures the ground current due to insulation leakage in electrical heating elements. The circuit uses a CT to measure the current being supplied to at least one of a plurality of electrical heating elements. Using a comparator circuit and noise rejection circuitry to prevent erroneous tripping, once the current reaches a predetermined threshold, a signal is sent to a switch that causes a non-volatile memory device to clear thereby de-energizing the coil of the contactor that provides power to at least one of the heating elements.