Building service ground fault interrupter

A ground fault interrupter for a building having associated therewith a power meter mounted in a power meter socket, positioned to interrupt utility power service to the building in case of a detected ground fault, comprising in combination:

• a. A sensor for detecting the fault current at the utility power service entrance to said building, wherein said sensor is a split core current transformer having two halves adapted for engagement about said utility power service entrance between said power meter socket and said building;
• b. a contactor, selectively movable between open and closed positions, mounted for temporary use in series with said power meter and utility power service to said building;
• c. a microprocessor based circuit for monitoring and evaluating fault current detected by said sensor and controlling the selective movement of said contact switch between said open and closed positions, wherein said microprocessor based circuit includes a programmable microprocessor containing a monitoring program which iteratively checks ground fault current as indicated by said sensor, the state of the contactor as recorded in a memory in said circuit, whether said sensor is present, whether power is provided to the service, and the voltage level of the service as determined by an input from a voltage level detector in said circuit, said microprocessor being operable in response to detecting ground fault current, absence of power, or low voltage to open said contactor;
• and,
• d. a housing surrounding said contactor and microprocessor based circuit for cooperative engagement between a power meter socket and a power meter on the building such that said contactor is serially connected between said power meter socket and said power meter.