Many people do not know what a circuit breaker really does. A circuit breaker breaks or opens the circuit if excessive current flows through the wires in the circuit. The difference between a circuit breaker and a fuse is a circuit breaker can be reset while a fuse is a one shot device. For example, Square D breakers are circuit breakers which when tripped can be reset and put back into service once the overload condition has been removed. A fuse on the other hand has to be replaced with another fuse of the same capacity before the circuit can be put back into service.
While all circuit breakers perform the same basic duty, some circuit breakers perform additional duties. For example, Zinsco breakers can detect not only overcurrent conditions within an electrical circuit; they can also detect ground faults. A ground fault is electrical current that uses the physical ground as a conductor. Instead of the electrons flowing down a wire, the ground is used as the wire. They are very dangerous to people’s lives so this breaker will open if a ground fault is found.
FPE circuit breakers can be used in specialized locations, such as bathrooms, kitchens, and other wet locations. The National Electrical Code states that any outlet within six feet of a water supply must be a ground fault type. Whereas a Zincso breaker detects a ground fault anywhere along the entire circuit, these breakers will immediately isolate a small portion of the circuit.