The home electric system relies on key components to function properly. From the main service panel and disconnect switch, to the circuit breakers and electrical meter, homeowners should know the role of each electrical component so they can quickly diagnose and address minor electrical issues.
Electrical service connection and meter
Every home’s electrical system is connected to the local utility company through service cables that attach to the home’s meter base. The electric meter plugs into the meter base and measures the amount of electricity being used by the home.
The home’s disconnect switch is mounted on an outside wall near the electric meter and can shut off power to the entire home without needing to access the main service panel, which is located inside. If an electrical system doesn’t have a disconnect switch, then power can be shut off at the main circuit breaker.
Main service panel
The main service panel is attached to the meter and houses the circuit breakers. Two hot wires connect to big screw terminals and deliver all power to the panel. The neutral wire conducts electricity to the utility after it has flowed through the system, completing the electrical circuit.
Main circuit breaker
A typical service panel provides 200-amp service and controls power to the individual circuit breakers housed in the panel. Shutting off the main breaker will stop power to the branch circuit breakers in the panel, but won’t keep power from flowing to the panel.
Branch circuit breakers
Branch circuit breakers control the flow of electricity to a certain part of the home. Devices and appliances plugged into a particular circuit will lose power if the breaker is tripped.
Switches, receptacles (outlets), light fixtures, and appliances are connected to individual branch circuits. Each of these devices requires electricity to function. Controlling the number of devices plugged into a particular circuit and drawing power simultaneously will help prevent tripping breakers.
Switches can be single-pole, three-way, four-way, and dimmer. Slipping a switch off “opens” the circuit by interrupting the flow of power to a device.
Also called receptacles, electrical outlets are typically 15-amp or 20-amp. High-demand appliances like clothes dryers and electric stoves may need 50-amp outlets.
A few different types of wiring found in a home electrical system are non-metallic cable, Bx cable, Nm cable, and wiring concealed in conduit.