How to Test a Circuit Breaker or Fuse? (AVOID Doing This!)

Circuit breakers are protective components of your home’s electric system. They protect your electrical system from overheating and overloading.

Circuit breakers should be able to perform three main functions. When closed, they must conduct the electric current effectively. When open, they should insulate the contracts from other circuit breakers efficiently. The third is a protective function; circuit breakers should be able to disconnect any faulty current as fast as possible if any problem occurs.


If you suspect a problem with your circuit breaker, you should perform a circuit breaker test to determine and troubleshoot the problem.

Why Test a Circuit Breaker?

A bad circuit breaker increases the risk of an electrical overload. It may cause a short circuit or even fire in some cases.

It’s essential to test a circuit breaker to make sure of the flow of electricity in the circuit breaker panel.

Sometimes, the problem is not with the breaker itself, even if it keeps flipping. Therefore, a home test for a circuit breaker is important.

How to Tell If a Circuit Breaker Is Bad?

It might be difficult to diagnose circuit breaker problems. A flipping circuit breaker may not be the problem. The fault could be in the wiring, or there may be a short circuit or a power overload.

It’s always a good idea to start with a routine check. Look for tell-tale signs in the panel or switches. Following are some of these signs to help you tell if your circuit breaker is bad.

  • It’s very hard to turn your breaker on or off
  • There’s heavy corrosion
  • The handle of the circuit breaker keeps flipping back and forth with no clear “on” and “off” positions.
  • The breakers are blackened, burnt, or overheated.
  • If the power doesn’t get to the breaker, there might be a problem with the bus bar in the breaker panel.
  • If you smell smoke or feel heat in the breaker or the panel, it’s best to shut off the main switch as a precaution.

After this routine check, you can begin testing your circuit breaker to find the problem. It’s easy, and you can do it yourself.

How to Test Circuit Breakers?

There are many ways to test a bad circuit breaker. These different tests can help you determine a variety of issues.

How to Test Circuit Breakers with a Neon Tester?

Neon testers check for hot wires and shock danger. You can use them in two easy steps:

  1. Touch the probes of a neon tester to the tested wire.
  2. The tester will light up if there’s an electric current in the wire.

How to Test Circuit Breakers with an Electrostatic Wand?

This device is also called a volt stick. Unlike the neon tester, an electrostatic wand can determine if the wire is hot without directly touching it.

All you need to do is:

  1. Hover it above the circuit breaker you’re testing.
  2. A light will show if there’s electricity.

This method isn’t very reliable. An electrostatic wand may pick up signals from other wires not associated with the circuit breaker tested.

How to Test Circuit Breakers with a Clamping Ammeter?

If your circuit breaker trips every time it’s reset, it may be overloaded. You can check for this by a clamping ammeter. A clamping ammeter is used to test overloads and shorts. It determines whether there’s an electric current in the circuit.

Follow these steps to test your circuit breaker using a clamping ammeter:

  1. Clamp the device to a single wire.
  2. It might indicate an overload.

How to Test Circuit Breakers with an Electromagnetic Circut Finder (Current Tracer)?

An electromagnetic circuit finder tests whether your circuit breaker has electricity. It also determines which individual breaker controls the circuit.

To use the electromagnetic circuit finder, follow two simple steps:

  1.  Plug the transmitter into the receptacle.
  2. Pass the tracer over the circuit
  3. The reading of the electric current will show on the receiver.

How to Test Circuit Breakers with a Voltmeter?

A voltmeter is a popular tool for testing circuit breakers. It measures the voltage running through the electrical circuit.

Here’s how to use a voltmeter:

  1. From the voltage options, choose a voltage that’s higher than the maximum expected.
  2. Insert the black end in the hole labeled “COM.”
  3. Plug the red end on the hole labeled “V,” “MA,” or the one with the lowest number.
  4. The current should read on the screen.

There’s one drawback to the use of a voltmeter. Having a voltage doesn’t necessarily mean that the load runs efficiently through the circuit. You might need another type of testing if the problem remains.

How to Test Circuit Breakers or Fuse with a Multimeter?

A multimeter is a multipurpose measuring device. It measures amps, volts, and ohms in breakers, outlets, and fixtures.

A multimeter combines the functions of a voltmeter and an ohmmeter. This makes it a more efficient testing method.

Follow these steps to test a circuit breaker using a multimeter. 

  1. Flip the tested breaker “on.”
  2. Use the AC volts settings (ACV) in the multimeter to test the circuit breaker.
  3. Touch the red prong of the multimeter to the breaker’s terminal screw and the black to a ground screw. You can find a ground screw in a metal bar on the right of the panel.
  4. If the reading on display is zero, the breaker needs to be replaced.
  5. You may follow the same steps with the ohms settings to test your breaker’s resistance.

Safety Tips for Testing Circuit Breakers

Here are some safety precautions to follow before testing your circuit breakers:

  1. Make sure the area around the panel, the floor, and even your own hands are dry.
  2. Use a flathead screwdriver to unscrew the cover of the circuit breaker. Make sure to hold it to avoid damage and injury.
  3. Always determine which breaker you’re testing.
  4. Turn off all devices and lights powered through the breaker you’re testing.
  5. Wear protective equipment, including goggles and safety boots.
  6. Turn the electricity off
  7. Contact an electrician if you don’t have experience with electricity.
  8. Always read and follow the manual of the tools that you are using as these instructions might differ.

When to Contact a Professional Electrician?

Testing a circuit breaker isn’t for everyone. It’s recommended to get professional help if you suspect a persistent problem with your circuit breaker. If you see or smell burning or damage, call the electrician.

Be cautious. Circuit breakers and electrical panels can cause deadly shocks.


Circuit breakers can be overloaded, overheated, or simply dead. The question is, how to tell if a circuit breaker is bad? Easy! Just follow your senses. The smell of smoke, the presence of corrosion, and exposure to water are among the tell-tale signs.

Wondering how to test a circuit breaker? You can use many devices, but a multimeter is the most reliable as it combines the features of various measuring instruments.


Installing Circuit Breakers