As shown in figure "A" of the ungrounded distribution system with possible ground faults shown in the illustration, under what conditions would an outage likely occur due to a ground fault causing a circuit breaker to trip? EL-0129

Correct Answer: Option A — two ground faults associated with different phases

Per 46 CFR Subchapter J and IEEE 45, an ungrounded marine electrical system tolerates a single ground fault without interrupting power. However, a second ground fault occurring on a different phase creates a direct line-to-line short circuit, causing protective circuit breakers to trip.