Each wire powers one “bus” (copper vertical leg) inside the main service panel. That’s why you usually see two columns of circuit breakers (or fuses) when you open your service panel door.

Other signs of out-of-date electrical wiring include discolored outlets or switches and sparking. If you see any of these, ...

This protects the wiring and the appliance if something goes ... They detect faults and then stop the flow of electricity. Small circuit breakers protect individual household appliances, whereas ...