Electrical Guide: How Do Breaker Boxes Work?

Electrical Guide How Do Breaker Boxes Work

Breaker boxes are the gatekeepers of your home’s electricity network. They perform double duty to power up your home. They send the power that flows into your house to circuits that pump electricity throughout your home. Secondly, they protect those circuits with circuit breakers to prevent overloads from occurring by breaking the flow of electricity when there’s too much power to handle.

This article will explore how breaker boxes work and the reasons you may need to invest in an upgrade or replace your current box.

  • What is a breaker box?
  • Location of breaker panels
  • Elements of a breaker box
  • Sizes to consider
  • When to upgrade your breaker panel

A breaker box goes by many names. Some people call it a breaker panel, circuit breaker box, electrical panel, breaker box, or distribution board. Whatever you happen to call your breaker box, it’s important to understand how vital it is to your electrical system and to know how to operate it safely.

What is a breaker box?

A breaker box is the housing system for your home’s circuit breakers that protect the electrical flow to your home. Every ounce of your electricity flows through this pivotal, but often overlooked, piece of equipment in your home. When everything is running smoothly, you likely won’t give it very much thought, but when an area of your home experiences an electrical blip, this is the hub to check first.

Your breaker box, or circuit breaker box, is the link between the power grid and all of your home’s wires and circuits that are used to power your home. The service panel within is the primary distribution point that feeds power to all the outlets, lights, heating, cooling, appliances, and everything else that runs on electricity within your home.

Break it down for me

Power lines feed electricity to your breaker box via underground lines or power poles through a service drop. Once the electricity reaches your box, it is sent through branch circuits to power everything in your home.

The main function of your breaker box is to protect your home from electrical overloads. To prevent hazardous conditions, breakers shut down the power when they detect too much electricity.

Ever trip a breaker by plugging in too many appliances at once or using a tool that puts too much stress on your system? When this happens, you have to make a trip to your breaker box to flip the breaker back on. Before breaker boxes, fuse boxes were the norm, and homeowners would have to replace the fuse in these situations.

Ample capacity

Older homes that were built before the 1960s may still use fuse boxes or breaker boxes that are only rated for 60 amps. As the size of homes has increased through the years, so has the amperage capacity of breaker boxes. Amperage, often referred to as amps, is how we measure electricity. Nowadays, most homes have a breaker box outfitted for up to 200 amps to accommodate all the appliances and electricity usage in modern homes.

Location of breaker panels

When one of your outlets or appliances has an electrical mishap and shuts off, you must locate your breaker box to see if a switch has been tripped. You may have plugged in one too many things, and doing so overloaded the system. Here are some of the most common places to find your breaker box:

  • Garage – the most common location for breaker boxes.
  • Utility closet – not a common location for most homes, but not unusual in townhomes or smaller duplexes.
  • Basement – for homes that are fed electricity from the power grid through buried power lines, this is a common place to find a breaker box.
  • Pantry – hallways on the bottom floor of the house or pantries are another spot where you can find an electrical panel for smaller homes.
  • Outside wall – older homes sometimes have an electrical panel on an exterior wall, but it is not as common.

When a breaker gets overloaded, it will shut off to prevent the circuit from getting any more flow of electricity that could spark a fire or cause damage. Once you suspect a tripped breaker, turn off anything you had plugged in or had running during the outage—most importantly, turn off the last thing you plugged in, as that is the likely suspect of the issue.

Once you locate your breaker box, look at the panel for a breaker no longer in the “on” position. Once you find the culprit, turn it to the full “off” position if it’s stuck in the middle before flipping it back on. If it’s already in the “off” position, then flip it back on to have it fully reset. If it doesn’t work the first time, give it another flip off and on to see if that does the trick.

Elements of a breaker box

Speaking of “on” and “off” switches, let’s take a moment to examine the interior of your breaker box. Opening up your breaker box for the first time can be a little overwhelming, but soon, you will be able to work with it without any hesitation!

While not every breaker box is designed exactly the same, most have general elements you can expect across the board. At first glance, you’ll notice a bunch of switches. These are your breakers. Each breaker controls one circuit, which typically controls a room or an area of the house. Each breaker can range from 15 to 200 amps, although most are 15, 20, or 30 amps.

Most breaker boxes have 20 to 40 breakers, depending on the size of your panel. Behind the scenes, there is a hot bus bar and a ground bus bar. Ground and power wires connect to each switch you see when you open your box.

There’s usually a single switch near the top of the panel, which is your main breaker. This guy has the power to shut off electricity to your whole home! The two columns of numbered switches comprise the rest of your breakers. They will not feed power to any part of the home when set to the “off” position.

Your panel door should have a guide with labels for each breaker indicating which part of your home each one powers. Once you flip the breaker to the “on” position, power will be able to reach that area. If the previous homeowner never got around to updating the labels of your box, it could be mislabeled, so you may have to figure out which switch powers what. Teamwork helps win this game, and it is worth playing to ensure you know which breaker to go to if you ever experience an outage.

Single-pole switch

Single-pole switches usually have a rating of 15 or 20 amps. These switches are the most common for home circuits of 120 volts and power most devices and smaller appliances in your home.

Double-pole switch

As the name suggests, a double-pole switch features two connected switches. These switches use higher amperage and can handle 240 volts. Double-pole switches usually power equipment such as water heaters, air conditioners, furnaces, EV charging stations, and other circuits requiring high voltage.

Sub panel

Only some electrical panels will feature a sub panel. These are typically added after the breaker box is put in and are more common when a home is connected to a backup generator or when they are installed to power a specific area of your home or other buildings on your property. If your breaker box has one, you’ll see it next to the main box.

Sizes to consider

When shopping around for a new breaker box, it’s wise to consider the amperage rating it offers. Usually, you will notice 100-amp or 200-amp ratings used for residential breaker boxes. The ratings indicate the electrical capacity of the unit.


You can power lights, some appliances, and outlets with a 100-amp breaker system. These units are really only compatible for smaller-sized homes that don’t need to power central air or heat.


This is the most common type of amperage used for average homes and new construction. It can run air, heat, and all of your appliances without stress. However, if you have a larger home with many electrical components, it may be worth looking into a larger breaker box.


For larger homes with a higher demand for electrical needs, consider a breaker panel that offers 250-amp. If you’re in the market for a new breaker box and know you will need to heat, cool, and run electricity to many spaces, such as to a new addition, upgrading to a 250-amp unit may be useful.

When to upgrade your breaker box

Most homeowners will experience the occasional tripped breaker. It happens from time to time. A tripped breaker is a sign that your breaker is doing its job and keeping you safe. However, there are other instances when your breaker tries to tell you something isn’t right and should be checked out.

Spots or burned areas on the panel or outlets

If you ever notice black spots or burned areas on your breaker box or outlets, that is not something to brush off. These are telltale signs that your unit is experiencing faulty wiring or a short circuit. Calling a professional to address the issue is imperative to prevent a significant electrical failure that could result in a house fire.

Still rocking a fuse box

If your home is on the older side and still using a fuse box, it is likely time to upgrade. A breaker box is a lot easier and safer to manage. Plus, it’s always a good idea to bring in a professional electrician so they can thoroughly survey your system to ensure everything is working correctly.

Funny smells or sounds

Anytime you see melted wires or smell anything burning near your electrical panel, it is a major red flag and should be taken seriously. Any heat or hissing sounds also indicate a serious problem and your breaker box must be looked at by a professional as soon as possible.

Frequent flickers

It’s time to upgrade your breaker box if you continually experience flickering or dimming lights. These are signs that your system does not have a steady flow of electricity, and certain circuit breakers could be going bad.

If you experience any of these problems, we highly recommend contacting a qualified electrician in your area to assess the problem and correct it before any hazards pop up.


The next time you experience a tripped breaker, you will know exactly where to go, what to do, and whether you need to call an expert to help address the issue. Most of the time, it’s just a matter of locating your breaker box and flipping a switch, but some instances require a professional touch.

  • If your current breaker box doesn’t offer enough amperage or you’re still using a fuse box, it may be time to upgrade your unit and call an electrical contractor.
  • If you are about to build an addition or have a home generator added to your home, new wiring and even a sub panel may be in order and will require a qualified, licensed technician to ensure the job is done safely.
  • Anytime you notice evidence of burning or unusual light activity, be sure to call a professional to come in and assess your situation.

Ongaro & Sons – your electrical experts

Ongaro & Sons is a family-owned business in its fourth generation of operation. We consistently deliver the highest level of service and value in our industry, ensuring stability for our valued customers. Our friendly team offers heating, cooling, plumbing, electrical, and solar installation services for the North Bay area.

When you need electrical services for your home or business, contact Ongaro & Sons here or call us at 707-419-3135. Our fully licensed and trained technicians deliver quality electrical installations and repairs at a fair price and are here to help you safely and conveniently meet all your electrical needs.