The electrical panel is a major component when it comes to understanding how your home operates, so knowing its anatomy is important. The panel is usually mounted in a garage, basement, or a laundry room. When you open the panel, you’ll see single circuit breakers in two columns. Additionally, there’s a main switch above the columns that controls power to the whole house.
A single circuit breaker controls the electrical current that flows to a specific outlet and it’s meant to protect your home from power surges or current overloads. A surge is when there’s a brief spike in your home’s electrical current. It can occur when large appliances, such as refrigerators or air conditioners, kick on or when there are nearby lightning strikes. An overload is when more amperage travels across a circuit than it is set to handle. For example, a wire that can safely carry 15 amps should be protected by a 15-amp breaker. If the wire is connected to a 20-amp breaker, it allows 20 amps to travel across a wire that’s only designed to handle 15 amps.
For these reasons, breakers are designed to fail safely and prevent problems such as a fire. If the current flowing through one of the breakers exceeds a certain level, the switch will automatically break the circuit (flip to the “off” position) and protect anything beyond that switch. When the switch is in the “on” position, power is flowing to that outlet. If it’s “off,” there has either been a power surge, a current overload, or someone manually turned it off.
It’s imperative that your breakers are labeled to identify what circuits connect to each outlet and avoid confusion if there’s a tripped breaker. Usually the builder or electrician will label the panel for you or you can do it yourself as soon as you move in. These labels should be located next to their corresponding switches or on the inside of the panels’ cover. The identifying stickers can relate to either specific appliances (dishwasher, stove, etc.) connected to corresponding outlets or the actual location of the outlet (kitchen, living room, etc.)
If you move into your home and there aren’t any labels in the electrical panel, you should take care of it immediately. You can leave the main breaker (located atop the single switches) on and turn the others off. Then, turn one switch on at a time and take a look around the house for appliances or outlets that are working and then label that switch. Do this with each breaker in both columns.
About 200 people die annually from household electrocutions. Power leaves the electrical panels on hot or energized wires, works through the device or outlet, and then the current comes back to the panel along neutral wires. Electrocution occurs when a person’s hands touch hot and neutral conductors, which causes the current to complete its circuit through the body.
All of those neutral circuits connect to a neutral bar in your electrical panel. They then connect to the main circuit neutral wire where it returns the current to the utility company’s transformers, which is usually the source of your electricity. So power comes from the electrical company’s line, through the meter located on the outside of your home, and into your service panel.
When working with electricity, it’s important to turn off the circuit breaker where you’re working. Electricity is very dangerous, causing about 4,000 injuries per year, so it’s best to call a certified electrician if you need work done or have any questions.