What is the function of a circuit breaker?

A circuit breaker serves a crucial function in electrical systems by protecting circuits from overloads and short circuits. When an excessive amount of current flows through a circuit due to an overload—often caused by too many devices being powered by the same circuit—or due to a fault (like a short circuit), the circuit breaker is designed to detect this unsafe condition.

Once it senses the abnormal current flow, the circuit breaker automatically interrupts the circuit by tripping, which cuts off the electrical supply. This action prevents potential hazards such as equipment damage, electrical fires, or even electrical shock. Therefore, the main role of a circuit breaker is to ensure safety in electrical systems by acting as a safeguard against dangerous conditions.

In contrast, measuring electrical current is the function of an ammeter, while increasing voltage would typically require a transformer. Storing electrical energy is associated with devices like batteries or capacitors, not circuit breakers. Thus, the ability of circuit breakers to enhance safety in electrical installations by providing overload and short circuit protection is their fundamental and most important function.