Patent ID: 6381113
Filing Date: 2002-04-30
Classification: H02H

Abstract:
A leakage current protection device for use in an electrical system having a neutral lead, a ground lead and at least one power line lead extending from a source of energy to a load comprising:a differential transformer having a core, opposed primary windings producing bucking fluxes representative of current to the load and current from the load, and a secondary winding; circuit opening means to open the power line lead in response to a trip signal generated in said secondary winding when a leakage current above a predetermined magnitude occurs; a supplemental secondary winding on said differential transformer; switch means to close the circuit to said supplemental secondary winding to simulate the occurrence of a leakage current in order to test the protection device; and time delay means to prevent current flow to the ground lead until said circuit opening means has been actuated by current flow to the neutral lead, thereby decreasing the chances that other protection devices in the electrical system would erroneously sense the test simulation as a leakage current.