Overload Protection

electricity
Circuit breakers do not blow like fuses. They are switches that automatically trip open to interrupt the flow of electrical current when it overloads the circuit.

Power is distributed through your house through various electrical circuits that start in the main entrance panel. The 110-120-volt circuits have two conductors -- one neutral (white) wire and one hot (black) wire. The 220-240-volt circuits may have two hot wires alone or a third, neutral wire may be added. In all cases, the hot lines are attached directly to the hot main buses. The neutral wire is always connected to the ground bus and never, under any circumstances, should it pass through a fuse or circuit breaker.

Fuses and circuit breakers are safety devices built into your electrical system. If there were no fuses or circuit breakers and you operated too many appliances on a single circuit, the cable carrying the power for that circuit would get extremely hot, short circuit, and possibly start a fire. To prevent electrical overloads, circuit breakers and fuses are designed to trip or blow, stopping the flow of current to the overloaded cable. For example, a 15-ampere circuit breaker should trip when the current through it exceeds 15 amperes. A 20-ampere fuse should blow when the current through it exceeds 20 amps. A fuse that blows or a circuit breaker that trips is not faulty; it is doing its job properly, indicating that there is trouble somewhere in the circuit. A blown fuse or tripped circuit breaker usually means there are too many appliances plugged in to that circuit or some malfunctioning device, like an appliance with an internal short, is connected to the circuit. Locate and eliminate the cause of the trouble before replacing a blown fuse or resetting a tripped circuit breaker.

Caution: Never try to defeat this built-in safety system by replacing a fuse with one of a higher current-carrying capacity. The fuse or circuit breaker capacity should be equal to or less than the current-carrying capacity of the conductors. For example, don't replace a 15-ampere fuse with a 25-ampere fuse. Replace fuses and breakers only with ones of the same size and amperage.

Circuit breakers do not blow like fuses; they are switches that automatically trip open to interrupt the flow of electrical current when it overloads the circuit. To reset a tripped breaker, turn it fully off and then back on.