Assessment for Lineworker Progression (ALP) Practice Test

The difference lies in how each device clears a fault and whether it can be reused. A fuse interrupts by heating until its metal element melts, opening the circuit; once it has blown, it cannot be reset and must be replaced. A circuit breaker clears a fault by tripping a switch and opening the circuit; after the fault is fixed, the breaker can be reset by turning it back on. Both devices are rated for a specific interrupting capacity—the maximum fault current they can safely interrupt—but the practical distinction you should remember is that breakers are reusable, while fuses are sacrificial. In practice, that means replacing blown fuses and resetting tripped breakers after ensuring the circuit is safe.