Patent ID: 8072715

Claim:
A method comprising: receiving a single phase-to-ground fault signal, the single phase-to-ground fault signal indicating that a first phase-to-ground fault is present on a first phase of an ungrounded power system; receiving a double phase-to-ground fault signal subsequent to receiving the single phase-to-ground fault signal, the double phase-to-ground fault signal indicating that a double phase-to-ground fault is present on the ungrounded power system due to the first phase-to-ground fault on the first phase and a second phase-to-ground fault on a second phase; and providing for a delay of a predetermined duration while the single phase-to-ground fault signal indicates that the single phase-to-ground fault is present on the ungrounded power system and the double phase-to-ground fault signal indicates that the double phase-to-ground fault is present on the ungrounded power system, thereby allowing for an opportunity to isolate the phase-to-ground fault on the first phase from the phase-to-ground fault on the second phase prior to expiration of the delay.