Must Know About Circuit Breakers

How to Use a Circuit Breaker Finder

What Is a Circuit Breaker Finder?

Circuit breakers are very convenient and common safety devices used to protect your electrical system from overloads and other hazards. But unless your electrical service panel (circuit breaker box) is very carefully mapped, it can be difficult to identify which breaker controls which outlets, switches, or light fixtures

How a Circuit Breaker Finder Works

An electronic circuit breaker finder includes two parts: a transmitter and a receiver. The transmitter plugs into a household outlet (or light socket, using an adapter; see below) for which you’re trying to identify the controlling circuit breaker or fuse

Install the Receiver Battery

The receiver on circuit breaker finders is powered by a battery. The model shown here uses a 9-volt battery installed in the handle. The battery compartment is easily accessed by sliding a cover back on the bottom of the receiver.

Test the Receiver and Transmitter

The next step is to confirm that the receiver will pick up the transmitter’s signal. Plug the receiver into a wall outlet. The outlet power should be on, and the transmitter should light up, indicating power. Place the receiver near the transmitter. The receiver should light up and/or beep to indicate it has picked up the transmitter signal. You can now use the device to locate the matching circuit breaker in your breaker box.

Match the Circuit to Its Breaker

Open to the door to your breaker box. Hold the receiver so the sensor tip is at a right angle and directly on the face of a circuit breaker. Slowly move the receiver up and down over the rows of circuit breakers while continually lowering the receiver’s sensitivity until only one breaker or fuse causes the receiver to beep. (Note: Sometimes an adjacent breaker or fuse may cause a beep due to the routing of the wires in the panel.)



Turn on the lights in every room of your home so that your helper can more easily identify which breaker you have turned off. Remember to turn on switches that are connected to electrical outlets.

Give your helper the floor plans, a pencil and a small appliance (such as a digital clock) to plug into receptacles to test for power.

Open the door of your breaker box and begin with the first breaker at the top of the row. Communicate to your helper, via radio, that you are going to flip the first breaker. Ask your helper to tell you the location of the light or lights that went out. Your helper will also need to test each outlet in the room by plugging in the small appliance. Have your helper write a “1” on each light and receptacle in the plans that is connected to breaker No. 1.

Tear off a small piece of masking tape and place it next to the breaker and write the location that is connected to the first breaker with a permanent marker. You can also write directly on the breaker box if you don’t want to use tape.

Switch the breaker back to the “on” position. Your partner can turn out any lights in the room once they’re marked on the plans.


How to Map Electrical Circuits in a Building

How to Make a Map of the Electrical Circuits in a Building

Each circuit breaker or fuse on your electrical service panel in a building should be identified to show the area of the building whose circuits it protects. This can be done by putting adhesive-backed paper or plastic stickers next to each circuit breaker or fuse.

Prepare a Building Floor Plan

To start with, draw a floor plan of the building whose circuits you need to trace. Make your floor plan drawing floor-by-floor or room-by-room, whichever is more convenient, but be sure to include every area that has electric service. Include porches, garages, outbuildings, etc.

Find the Main Electrical Panel and Find any Sub Panels

Electrical Emergency Response: One of the most important safety measures to take in a building is to make sure that the adult building occupants know where to shut off electrical power in an emergency

Find and Label All Main Electrical Shutoff Switches First

The best electrical practice is for a building to have a single, easily accessed, plainly-marked main electrical shutoff switch.But some buildings, especially older ones, may have no single main power shutoff, and may be powered by multiple electrical panels.If the main electrical panel serving a building has more than six switches and has no main shutoff switch, we recommend that one be installed.

How to Find Remote Fuse or Circuit Breaker Panels in a Building

What if you don’t know if there are any remote electrical panels or not in a building? Sub panels should be easily found and identified but often they’re hidden away such as in this odd panel photo courtesy of Timothy Hemm.


Tips for Troubleshooting Your Circuit Breakers

Identify Your Tripped Circuit Breaker

Your circuit breaker emits a humming sound when it is overloaded but has not switched off yet. Inside your electric access panel, the tripped breaker lever can usually be found between the “on” and “off” position

Test Your Circuit Breaker

Check the lever by moving it from ‘on’ to ‘off’ a couple of times to check how loose it is. If your breaker has no ‘give’ and moves easily then it is faulty and you need to have it replaced as soon as possible.

Switch Off All of Your Appliances Again

Switch off all your appliances that are connected to your circuit breaker but make sure to do it all at once to prevent a surge of electrical power when you reset it. If your circuit breaker keeps on tripping then hire a professional to come and have a look at it.

Check Your Wiring

If your home has faulty wiring, then your circuit breaker will be tripping continuously and you may find yourself receiving electrical shocks when powering certain appliances of yours. This requires a trained professional so don’t try this on your own. Simply identify the problem and hire a professional to take care of it.

Have Your Circuit Breaker Tested for the Necessary Voltage

Touch one probe of the 120-240 volt tester to the tip of the “hot” wire, while touching the other tip to a bare copper grounding wire within the main electrical box. Use a neutral grounding terminal which is secured with ground wires and neutral wires for the probe. You will need to replace your circuit breaker if you find the right amount of voltage present.


What and Where Is My Circuit Breaker?

What Is a Circuit Breaker?

At its most basic, a circuit breaker is a box that contains several rows of switches. These switches are safety devices designed to trip when too much power tries to travel through the circuit, causing it to heat up. Inside each switch, either an electromagnet or a bimetallic strip serves to complete the circuit between the two terminals at either end of the switch. When an electrical wire is connected to the switch via the terminals, electricity flows through the magnet or the strip to complete the circuit.

Where Is the Circuit Breaker?

While every home is different, there are a few common locations where you are likely to find your circuit breaker. Circuit breakers are generally located in low-traffic areas of the home, such as a basement, garage, or utility closet. If you live in an apartment, your circuit breaker may be in a more central location, such as a hallway or laundry area. Most modern circuit breakers are located inside the home, but it’s important to note that your circuit breaker could be located on your home’s exterior as well. Your circuit breaker should appear as a metal box; you may only see the door if the box is recessed into your wall. The box and door may be a matte gray color, or they may be painted over to match the color of the surrounding area. If you can’t find your circuit breaker, call your residential electrician for assistance.