Fuse

Protecting a circuit from excess current is the fuse's only job: when the current exceeds its rating it blows and opens the circuit. Circuits with this tag show overload and short-circuit protection in household-style lighting and fan wiring, car electrical systems with fused branches, and the difference between a one-time fuse and a resettable circuit breaker. For example, "Using a fuse in a circuit" places a fuse in series with a lamp and battery to show where protection belongs.