Churning with voltage and resembling an explosion at the wire factory, your home’s electrical panel has a certain mystique. Understanding how it works can help you avoid potential dangers.
Inside, you’ll find single circuit breakers in two columns and a main switch atop the columns. If your home has a fuse box or has less than 100-amp service, it needs upgrading.
Electrical Service
A home’s main electrical panel is the distribution center that splits incoming electricity into circuits that run throughout the house to power outlets and appliances. Also known as a fuse box, it is usually a gray metal box mounted on the wall in a utility area like a garage or basement, but may also be contained in a finished cabinet in a living space.
The panels contain a number of components, including circuit breakers (some single and some double-pole) and fuses. Each breaker handles a specific amount of electricity and is rated for the maximum load it can safely carry.
The panels also include arc fault circuit interrupters, which prevent fires from starting and electrical regulation devices that can quickly change voltage levels in the event of overvoltage. They are also governed by building codes and must adhere to standards regarding their size, height and accessibility. For example, they must be easily accessible and able to be opened by a person at any time.
Circuit Breakers
An electrical panel, also known as a breaker box or a power panel, is the central hub for all wiring in your home. It contains both circuit breakers and fuses to manage and distribute electricity and provide protection against power surges.
Unlike fuses, which are made of wire surrounded by heat-resistant material, circuit breakers have switches that open and close to control the flow of current. If they detect too much current or excessive heat, the switch will trip and cut off power. You can then reset the breaker by flipping it to the on position.
The rows of single breakers that take up most of the interior of an electrical panel are labeled to show how much amperage they can handle. A 15-amp breaker might power lights or standard outlets, while 20-amp breakers are for high-use appliances like dishwashers or dryers. Double-pole breakers, which are larger and take up two slots in the breaker box, are used to protect circuits that run on two hot wires (or “hots”) instead of one.
Wiring
An electrical panel connects the external wires that come into your house to the internal wires that power the various rooms of your home. It is typically tucked away in a hallway leading to the garage, basement or closet, and often not visible from outside.
It may look intimidating, but an electrical panel is actually quite simple to understand. The bare ends of the main power wires enter the panel via a main disconnect switch and connect to hot busbars going down the center of the panel. The circuit breakers positioned along these hot busbars act as switches that shut off power to branch circuits when the current goes over their limit due to a surge or short.
Some panels also have a grounding busbar and neutral busbar for the grounding and neutral wires. These wires run to each room in your home and to light fixtures and appliances. Both circuit breakers and fuses perform the same basic function – they disrupt the flow of electricity to stop damage. However, breaker switches are reusable, while fuses contain a filament that melts at high voltage and is no longer useable.
Maintenance
The electrical panel is responsible for distributing electricity to every room in the house. It also handles incoming power from the electric company. In residential settings, the electrical panel is usually located in a garage, basement or utility closet. In commercial buildings, it’s often found in a dedicated electrical room or equipment shed.
Over time, your electrical panel will start to wear down. If you notice flickering lights, a strange buzzing noise or circuit breakers that frequently trip, it’s time to schedule a maintenance inspection. You may need to upgrade your panel if it’s over 25 years old or you need more space for additional circuits.
While you may not use it often, your electrical panel is an important part of your home’s safety. Be sure to follow proper precautions when handling your panel and keep it clean and free of debris. Where non-electrical persons are required to gain entry into panels for basic first-line breakdown intervention, ESUK’s Control Panel Entry training helps them do this safely and quickly.
