Anatomy of a Circuit Breaker Box

The main electrical panel, commonly referred to 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 safety mechanisms that can be found in your house.

Your household’s electricity is sent to your home from the utility company either through overhead power lines, underground conduits, or a combination of both. After passing through your home’s electric meter, the energy is then sent to the main electrical panel to be distributed throughout the house. The main panel is your dwelling’s power distribution center, providing electricity to outlets, light fixtures, and appliances throughout the house.

Electrical service panels are manufactured in various types, sizes, and configurations. The main panel may be mounted on the exterior of the building or, alternatively and more commonly, located inside the building, providing easier access and better security.

The main panel receives electricity through 3 main incoming cables and then routes this power to many smaller wires which create circuits throughout the entire house. The average breaker panel consists of 2 main “buss bars” which control power for the entire building. The main breakers draw electricity from the incoming energy source and transfer it to these 2 main buss bars. Sequentially, these 2 buss bars pass the electricity along to all the secondary breakers. The secondary breakers each control separate aspects of the house. For example, one may control the electricity flow to a particular room of the house, such as the kitchen, while another may control the power flow to the dwelling’s air conditioning unit.

Larger beakers found in buildings with a higher capacity may divert power to sub-panels. These sub-panels will have its own set of breakers, used to control a specific aspect of the house.

A ground wire (usually copper) is always installed with the building main service panel for safety reasons. This metal wire runs from the neutral connector located within the panel, to a metal rod driven into the ground.

Every home’s main electrical panel contains a mechanical switch for each of the circuits contained within the residence. These switches allow the circuit to be purposefully broken temporarily, thereby cutting power to that aspect of the home. These are used when service or repairs must be performed to electrical aspects of the building. Also, these switches may be “tripped” automatically due to a failure in the circuit, such as a power overload. This is to prevent damage to the electrical system, as well as to the building, such as an electrical fire.

The maximum power amperage capacity for your home is printed on the main breaker. Most residences have a 100-amp capacity, which is sufficient enough for all energy needs in the household. However, some newer homes are being built with a 200-amp capacity, ensuring sufficient energy capability into the future. Some older homes may be found with a 60-amp capacity or lower. This amperage is now considered insufficient for modern household needs and these homes should have an electrical upgrade for safety reasons.