The PB-Series AC Residual Current Circuit Breaker with Overcurrent Protection (RCBO) combines the ground fault protection of a GFCI with the familiar overcurrent tripping characteristics of a normal circuit breaker. It detects lower level ground faults that do not trip ordinary circuit breakers, but could lead to fires. It increases safety around boats and marinas, protecting against electrical shock hazards near water. It is suitable as: a single circuit solution for AC branch ground fault protection; AC main ground fault protection for a boat’s entire AC electrical system; portable generator ground fault protection.