Abstract: A circuit tests the health of a ground-neutral transformer within a ground fault circuit interrupter. This test can include testing both the ground-to-neutral detection circuitry and the differential current detection circuitry. The test circuit provides a conductive path through the respective cores of a differential transformer and the ground-neutral transformer of the GFCI device. A closed loop induces current from the differential transformer, which creates a current imbalance through the differential transformer. In a properly working device, the circuit breaker will trip, confirming the health of the ground-neutral transformer portion of the GFCI.

Abstract: In accordance with one aspect the present disclosure is directed toward a method for detecting arc faults on a power line. The method may include monitoring power signals associated with a power line and filtering the power signals to produce a high frequency signal and a low frequency signal. A mask signal may generated based on the low frequency signal, and the high frequency signal may be analyzed to extract a broadband portion of the high frequency signal. A fault counter may be incremented if the magnitude of the broadband portion is approximately greater than a first threshold level. A fault counter may be decremented if the magnitude of the broadband portion is approximately less than the first threshold level. A trip signal is provided to a switching device associated with the power line if the fault counter exceeds a predetermined fault limit.

Abstract: A circuit tests the health of a ground-neutral transformer within a ground fault circuit interrupter. This test can include testing both the ground-to-neutral detection circuitry and the differential current detection circuitry. The test circuit provides a conductive path through the respective cores of a differential transformer and the ground-neutral transformer of the GFCI device. A closed loop induces current from the differential transformer, which creates a current imbalance through the differential transformer. In a properly working device, the circuit breaker will trip, confirming the health of the ground-neutral transformer portion of the GFCI.

Abstract: In accordance with one aspect the present disclosure is directed toward a method for detecting arc faults on a power line. The method may include monitoring power signals associated with a power line and filtering the power signals to produce a high frequency signal and a low frequency signal. A mask signal may generated based on the low frequency signal, and the high frequency signal may be analyzed to extract a broadband portion of the high frequency signal. A fault counter may be incremented if the magnitude of the broadband portion is approximately greater than a first threshold level. A fault counter may be decremented if the magnitude of the broadband portion is approximately less than the first threshold level. A trip signal is provided to a switching device associated with the power line if the fault counter exceeds a predetermined fault limit.