When an electrical receptacle ceases to function due to an overcurrent event, several consequences typically occur. The circuit breaker, designed to protect the wiring from excessive amperage, will trip, interrupting the flow of electricity to that specific circuit. This effectively renders all outlets and devices on that circuit inoperable until the breaker is reset. For example, if a hairdryer, microwave, and space heater are simultaneously used on a single circuit, exceeding its amperage rating, the breaker will trip, and all three devices will cease to function.
This safety mechanism is critical to prevent overheating of wires, which can lead to electrical fires. Historically, before circuit breakers were commonplace, fuses were used for this purpose. A blown fuse, which melts a wire link when overcurrent occurs, also interrupts the circuit but requires replacement rather than a simple reset. The benefits of modern circuit breakers include their reusability and improved safety features like arc fault circuit interrupters (AFCIs) and ground fault circuit interrupters (GFCIs), which offer enhanced protection against electrical hazards.