Anatomy of a Circuit Breaker Box
The main electrical panel, commonly known as a “breaker box,” is the heart of your home’s electrical system. It is an essential device in the modern world, and one of the most important security mechanisms that can be found in your home.
Your home’s electricity is delivered to your home from the utility company through overhead power lines, underground conduits, or a combination of both. After passing through your home’s electric meter, the power is sent to the main electrical panel for distribution throughout the house. The main panel is the power distribution center of your home, providing electricity to outlets, lamps and appliances throughout the house.
Electrical service panels are manufactured in various types, sizes, and configurations. The main panel can be mounted on the outside of the building or, alternatively and more commonly, located on the inside of the building, providing easier access and increased security.
The main panel receives electricity through 3 main incoming wires and then routes this power to many smaller wires that create circuits throughout the house. The average breaker panel consists of 2 main “bus bars” that control power to the entire building. The main breakers draw electricity from the incoming power source and transfer it to these 2 main busbars. Sequentially, these 2 bus bars pass power to all secondary breakers. Each of the secondary switches controls separate aspects of the house. For example, one might control the flow of electricity to a particular room in the house, such as the kitchen, while another might control the flow of power to the home’s air conditioning unit.
Larger beakers found in higher capacity buildings can divert power to subpanels. These sub-panels will have their own set of switches, which are used to control a specific aspect of the house.
For safety reasons, a ground wire (usually copper) is always run to the building’s main service panel. This metal wire runs from the neutral connector located inside the panel to a metal rod buried in the ground.
The main electrical panel in each home contains a mechanical switch for each of the circuits contained within the residence. These breakers allow the circuit to be temporarily interrupted on purpose, thereby cutting power to that aspect of the house. These are used when services or repairs need to be performed on the electrical aspects of the building. Also, these breakers can automatically “trip” due to a fault in the circuit, such as a power surge. This is to prevent damage to the electrical system, as well as the building, such as an electrical fire.
The maximum power amperage capacity for your home is printed on the main switch. Most residences are rated at 100 amps, which is enough for all of your home’s power needs. However, some newer houses are being built with 200-amp capacity, ensuring sufficient power capacity well into the future. Some older homes can be found rated at 60 amps or less. This amperage is now considered insufficient for the needs of modern homes and these homes must have an electrical upgrade for safety reasons.