Patent ID: 7099130

Claim:
An interrupter circuit for connecting a load on a load side to a power source on a line side, comprising: a Ground Fault Circuit Interrupter (GFCI) circuit comprising line side phase and neutral terminals, load side phase and neutral terminals, and control circuitry interposed between the line side phase and neutral terminals and the load side phase and neutral terminals, the control circuitry operable to monitor a current imbalance in the load side phase and neutral terminals and to enter a de-energized state that isolates the load from the power source when the current imbalance exceeds a threshold; and a voltage monitor module operable to monitor a voltage between the line side phase and neutral terminals, and to generate a fault signal that causes the GFCI circuit to enter the de-energized state when the voltage between the line side phase and neutral terminals is not within a defined tolerance; wherein the defined tolerance defines an upper line voltage threshold and a lower line voltage threshold, and the voltage monitor module is operable to generate the fault signal when the voltage between the line side phase and neutral terminals is greater than the upper line voltage threshold or is lower tan the lower line voltage threshold.