Patent ID: 7715158

Claim:
A circuit interrupter comprising: at least one input conductor; at least one output conductor; at least one grounding conductor having an input side and an output side; a switch coupled between said at least one input conductor and at least one output conductor, said switch being coupled along said grounding conductor and being configured to disconnect said input side from said output side; a sensing circuit configured to detect both a around fault and also to determine whether said grounding conductor is at a voltage potential not equal to the voltage potential of terrestrial earth, said sensing circuit comprising an integrated circuit having at least one pin coupled to said at least one grounding conductor wherein said sensing circuit comprises a MOSFET inverter having an input with a high resistance, in communication with said at least one pin, wherein said at least one pin is configured to pass a voltage to said MOSFET inverter to allow said sensing circuit to determine whether the voltage present at said at least one pin is at a potential not equal to the voltage potential of terrestrial earth; a control circuit coupled to said switch and said sensing circuit; whereby, if said grounding conductor is at a voltage potential not equal to the voltage potential of terrestrial earth, said sensing circuit will cause said control circuit to automatically open said switch thereby disconnecting said input side of said grounding conductor from said output side of said grounding conductor.