Circuit breakers are made to stop an overloaded circuit or to prevent a short circuit. In a home, many breakers are 15 amps. If you plug in a stereo system that tries to pull 16 amps, the breaker will trip, or turn off, so that 16 amps do not travel through the electrical system in your home. In the event of a short circuit, a breaker trips and instantly turns off power to that circuit. If the breaker failed to trip properly the short circuit to quickly lead to a fire in the home.
The best way to test for a faulty device is to first unplug everything that is attached to that breaker from the wall, turn off every single light in the house, and then plug back in each device one by one until you get the breaker to trip. You can then determine if the device plugged into the wall is at fault or if the breaker is at fault Wire Pull Tester.
In the event that no devices seem to be tripping the breaker you should check the voltage on the circuit breaker. For this, you’ll need a multimeter or voltage tester. Check both the line and load side of the breaker for the proper amperage and voltage. If the voltage is not the same on both sides, you probably have a faulty breaker.
If you’ve discovered that you do indeed have a faulty breaker, it’s time to replace it. First, shut off all of the breakers one by one in the panel, and then turn off the main unit. Make sure each breaker is turned off and there is no power going to the panel with your voltage tester or multimeter. Next, you’ll need to replace the faulty breaker. Most houses built after 1960 use push-in or stab style breakers. These breakers simply pry out of the panel and are simple to replace. Disconnect the wires from the breaker, pry it out with a screwdriver or small pry bar, and connect a new one the same way. Be sure to replace it with a one that is the same amperage ratings. No matter what you do, do not put a different sized breaker in place of a smaller one!
Once the new breaker is correctly seated in the panel, connect the wiring back to it, and turn back on each breaker one by one, and finally turn on the main breaker. Check the new breaker for the correct voltage, and check the devices attached to that breaker to make sure they all work properly.
If you are replacing a larger breaker in an industrial or commercial situation, you can send the used breaker to be reconditioned, or even sell the used breaker to a company that reconditions them. There are many companies online that recondition used breakers. For customers who are replacing an expensive one, I recommend having the faulty one repaired and keeping it as a spare so next time you need to replace one you’ll have one ready to go.