Circuit Breakers and Main Circuit Breaker Panels

Circuit Breakers play a Key Role in Protecting your Home from Electrical Fires

By Mark J. Donovan

An electrical circuit breaker plays an important role in your home. It is a safety mechanism for preventing too much current from flowing through an electrical circuit. Circuit breakers reside in main circuit breaker panels within your home. Main circuit breaker panels are usually found in basements, garages or utility rooms.

How a Circuit Breaker Works

When more current flows through a wire than what it is rated for it heats up. The wire can get so hot that it actually can cause a fire. Fortunately the circuit breaker can prevent this situation from occurring, by shutting off the power to the circuit when too much current begins to flow through the circuit.

The advantage of a circuit breaker over its predecessor, the fuse, is that it can be reset after it has been shut off (or tripped).

To understand circuit breakers you first need to understand what a circuit is. A circuit is a loop that contains various loads and switches on it, such as lighting, stereo equipment, refrigerators, stoves, etc. These loads are connected into the circuit via electrical outlets and are controlled by switches in some cases.

There are many electrical circuits within your home. As a matter of fact each circuit breaker in a main circuit breaker panel represents a unique circuit.

Here are circuit breakers in a main circuit panel box.

Circuit breakers are installed in series with a circuit. When too much current flows through the wire, due to either too many loads on the circuit, or a faulty load that causes a short circuit, the circuit breaker recognizes this increase of current and immediately is tripped. When it is tripped, the power is shut off to the circuit.

When a circuit is tripped, it is important to figure out what caused it to trip. Usually it is associated with too many loads being turned on simultaneously, such as multiple power tools, or even hair dryers operating simultaneously. Sometimes, however it can be a faulty appliance.

Once you have figured out the cause and eliminated it from the circuit, for example unplugging some of the loads, or the faulty load from the wall outlet, you can then reset the circuit breaker to restore power to the circuit.

There are also ground fault circuit interrupter type circuit breakers (GFCI circuit breakers) for use in bathrooms, kitchens, garages and other areas where there might be water or high moisture levels. They are designed to trip under the slightest rapid current change to prevent serious or life threatening shock.

Circuit Breakers come in a variety of current ratings and styles. It is important to use the right circuit breaker with the type of wiring in the circuit. For example, a 15 Amp rated circuit breaker should be used with a 14-2/3 type Romex wire cable. A 20 Amp rated circuit breaker should be used with 12-2/3 type Romex wire cable.

Finally, it is import to select the right type of circuit breaker for the type of main circuit breaker panel in your home. So take a look at your circuit panel prior to running to the home improvement store.

Warning: When working with electricity use extreme caution to avoid the risk of electrical shock. Make sure to first shut off power at the main circuit panel and then confirm all power to the electrical fixtures and boxes are off prior to beginning any electrical work.

For help on building a new custom home, see’s New Home Construction Bid Sheet. The New Home Construction Bid Sheet provides you with the knowledge on how to plan a custom home building project, and what to look for when hiring contractors for your new home construction. It also includes a detailed cost breakdown table and spreadsheet for estimating your own new home construction building costs.

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