When you need to have electrical work done in your home, the power to the circuit being worked on will need to be turned off. This is done at the main electrical service panel or breaker box. You can think of the breaker box as the switchboard for all the electricity in your home. This is where the power comes into your home from the utility company and sends it out to all the circuits in your home. All the power in your home can be turned off at the main service panel. The only power that can’t, is the power that comes from the utility company.
Electrical Panel & Subpanel
The service panel is a steel box that has a hinged door on the front of it. It may have a lift-up panel on the front of it. When you open the door, you can access all the circuit breakers within the panel. Most homes have one panel that powers the whole house, but some may have a smaller one too. It is called a subpanel and controls power to a certain area like a larger kitchen, a detached garage or an addition to the home. The subpanel will work just like the main panel only it isn’t connected to the utility company, it is connected to the main panel. All the levers within the panel control a certain breaker. The lever can be switched to ON or OFF or moved to the position between them when a breaker trips. Breakers trip when there is an overload or there is another issue with the circuit. All the breakers should be labeled so you know exactly what area or appliance that breaker is connected to.
Wiring Behind the Electrical Panel Door
Most homeowners only ever need to open the door to access the breaker smirches. But if a circuit breaker needs to be installed or replaced, the protective cover around the breaker will need to be removed. This cover is usually held in place with screws and all access to the contents of the panel can be accessed when this cover is removed. It is very important to make sure the main circuit breaker is turned off before you remove the protective cover. Doing so will turn all the power off to the circuit breakers and household circuits, but it will not turn the power off from the utility company. This can be a dangerous situation because the panel remains live and still carries a deadly electrical current.
Main Circuit Breaker Function
The main circuit breaker will be positioned at the top of the panel but may also be at the bottom or on the side of your panel. It is a larger breaker than the rest of them. The main circuit breaker will also tell you what the total amperage capacity of the service panel is. For example, 100, 150, 200. Most new panels will have an amp capacity of 200 amps, but they can be higher. The main circuit breaker does not shut power off from the utility company which means the panel remains live.