Abstract: A method for determining the nature of a ground fault in a floating direct voltage load powering context includes measuring the load voltage and the current at a nominal balance point, both before and after closing a circuit to the load. The fault resistance and the fault voltage are determined as the solution to an equation in two unknowns given the conditions before and after application of load voltage or at least precharge.

Abstract: In one embodiment, an AC ground fault detector system senses an AC signal indicative of an unintended electrical path between a load driven by a power source and a reference potential using a capacitively coupled circuit.

Abstract: A fault detection system for detecting an unwanted electrical path between a reference potential and at least one of: a) a floating power source, b) a first power conductor coupled to a first terminal of the power source, and c) a second power conductor coupled to a second terminal of the power source. The system comprises an impedance network electrically coupled to the first and second power conductors and having an output terminal for providing a first voltage signal with respect to the reference potential, and an amplifier circuit responsive to the first voltage signal and to a reference voltage for generating an amplified signal indicative of the existence of the unwanted electrical path when the difference between the first voltage signal and the reference voltage exceeds a predetermined value.

Abstract: An AC ground fault detector system for sensing an AC signal indicative of an unintended electrical path between a load driven by a power source and a reference potential comprises a first power conductor coupled to a first terminal of the power source and a second power conductor coupled to a second terminal of the power source. A switching mechanism coupled to the first and second power conductors is operative for alternately connecting a phase of the load with the first and second power conductors according to a predetermined switching rate, whereby, during normal operation, voltages developed at the first power conductor and second power conductor are substantially constant with respect to a reference potential. In the event of an occurrence of the unintended electrical path of at least one phase of the load with the reference potential, time varying voltages are developed at the first power conductor and second power conductor associated with the switching rate.