How to Map Your Home’s Electrical Circuits

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Are you unsure which circuit breakers in your electrical service panel control which circuits in your home? Maybe you’re not even sure where your electrical panel is.

Well, you need to know. If you ever need to work on your wiring or have work done, such as to install a ceiling fan or a USB outlet, you will need to be able to turn the circuit off. If there’s ever an emergency, such as a flood, you’ll need to be able to turn the electrical panel off in a hurry. If the previous homeowner didn’t leave you a neatly labeled chart letting you know which circuit breakers operate which circuits, you’re going to decide how to map your home’s electrical circuits yourself.

Find Your Electrical Panel

If you don’t know where your electrical panel is, look for it in the basement or in your utility room. Some houses may have a sub-panel, which is a smaller electrical panel that may control the circuits in an outbuilding. If the house is an older house, it may have two electrical panels because the wiring was updated or expanded at some point.

Draw a Floor Plan of Your Home

You can use a free floor plan creator, or you can simply draw your floor plan on a piece of paper with a pen or pencil. You may want to use a new sheet of paper for each floor of your house. If you’re diagramming rooms with a lot of outlets and fixtures and appliances, like the kitchen, you may want to dedicate an entire page to each room.

Locate Your Switches, Outlets, and Light Fixtures

Once you have your floor plan drawn out, it’s time to find your switches, outlets, light fixtures, and appliances and mark them on the floor plan. You’ll want to use a code of some kind to indicate which marking is which. Maybe you can use letters. The letter “O” can stand for “outlet”, while the letter “S” stands for switch and so forth. You can also use color-coded highlighters to mark the presence of outlets, fixtures, and lights on your floor plan. Don’t forget to draw in appliances like the refrigerator, stove, and washer and dryer. These may be on their own, dedicated circuits.

Don’t forget to move furniture to look for outlets that you might not be using. Wall switches tend to correspond to specific fixtures, so you may want to mark that somehow as well.

Get Some Assistance

At this stage of the process you’re going to need someone’s help. Go to the electrical panel and turn off all the circuit breaker fuses. Your helper will go from room to room, testing switches and plugging something into the outlets in each room. A lamp is a good choice – if it comes on when you plug it in, the circuit is on.

Have your assistant go to the first room – bedrooms are a good place to start – and flip the light switch. Back at the electrical panel, you’ll turn on the first circuit. Your helper should let you know whether the light has come on and the outlets are all working in that room. Make sure to check all of the outlets in a given room; don’t just check one and assume that all the rest must be on that same circuit, too. They might not be. The previous owner may have wired the house oddly for reasons of his or her own, and there may be outlets on their own circuits for all you know.

If the first circuit doesn’t turn on the room where your assistant is, turn it off and turn on another circuit and keep doing that until you figure out which circuit controls the bedroom where your helper is standing. Label it on the electrical service panel directory and move on to the next room. Don’t forget to check which appliances the double, 240-volt circuit breakers control, too.

Remember, for rooms like bedrooms that could easily have the same level, be specific so that a future homeowner, or future family member, won’t have to stand at the electrical service panel wondering which of the circuit breakers labeled “bedroom” turns off the circuit to their bedroom. Use terms like “front bedroom” and “back bedroom” or “west bedroom” and “east bedroom” to help avoid this kind of confusion.

Mapping your home’s electrical circuits can take a long time, but it’s worth it when the power goes out and you need to check for blown fuses. Map your home’s electrical circuits today, and get to know your home a little better in the process.