Circuit breaker is another type of device that helps prevent electrical fires. As opposed to the common belief that circuit breakers prevent short circuits or electrical shock, their sole purpose is to protect wires from current overloads which cause overheating, and potentially melting or even igniting wire insulation. If electric current flowing through a wire exceeds the wire’s current carrying capability, the circuit breaker trips, and shuts off power to the circuit it connects. Common reasons for current overloads are power surges, short circuits, mismatched loads, and appliance failure. Circuit breakers are inexpensive and are resettable. However, repeatedly resetting a circuit breaker is not recommended. You should have a qualified electrician troubleshoot the problem.
Unlike circuit breakers, a fuse operates once, and then must be replaced. A fuse consists of a metal strip or wire fuse element, mounted between a pair of electrical terminals, and enclosed by a non-combustible housing. When excessive current flows through the fuse element, it overheats and melts, interrupting the circuit it connects. Fusses are commonly found in older houses. A negative aspect of a fuse is that by the time its fuse element melts, the wire it connects might have already had a current overload long enough to have compromised the integrity of the insulation. For this reason it is recommended that you replace your old panel and its fuses, with a new panel that uses circuit breakers.