What is the function of circuit breakers?

The function of a breaker is two fold. It has the ability to open an electrical circuit when the load current of the circuit becomes higher that the rating of the breaker. This is referred to as an overload trip. The other feature of a breaker is that it will open the circuit instantaneously on a short circuit condition. This is referred to as a short circuit trip.

The function of a circuit breaker is to cut off electrical power if wiring is overloaded with current. They help prevent fires that can result when wires are overloaded with electricity.