Every modern home is equipped with an electrical system controlled by an electrical panel. This is the hub for the home’s electrical system, housing circuit breakers that trip and cut off power to a specific circuit as a safety precaution.
Every homeowner needs to know the basic components of their electrical panel in case of an emergency or if they need to reset a tripped circuit breaker.
Breaker box
The metal enclosure houses the electrical panel, wiring, switches, and other components. The breaker box is typically mounted on a wall and has a single door on the front.
Source wires
The source wires come from the meter and enter the breaker box from the top. They typically include two hot wires, which connect to the main disconnect switch, and one neutral wire, which connects to the neutral busbar.
Main disconnect switch
This switch is located near the top of the breaker box and functions as the main breaker for the panel. If the main disconnect switch trips or is shut off, then the entire electrical panel loses power.
Hot busbars
The two hot busbars run down the center of the breaker panel and connect to the hot source wires, which supply power to the panel and circuits. The hot busbars have circuit breakers along the side.
Neutral busbar
The neutral busbar typically runs parallel to the hot busbars or to the side of the enclosure. It connects the primary neutral source wire to the neutral wires from branch circuits.
Grounding busbar
The grounding wires from the branch circuits converge in the grounding busbar, which is typically located near the bottom of the breaker box or runs parallel to the hot busbars.
Circuit breakers
The home’s individual circuits may be shut off by a corresponding circuit breaker. The three types of circuit breakers are Ground Fault Circuit Interrupter (GFCI), Arc Fault Circuit Interrupter (AFCI), and standard breaker (no protection).
Branch circuit wires
These wires include neutral (white), ground (bare copper or green), and hot (black) wires that run from the breaker box to the circuits in the home. A 120V circuit typically has three wires, while a 240V circuit can have three to four wires.