How to Check a Circuit Breaker
If you're like most people, chances are the only time you even look at your circuit breaker is when you trip the circuit in your home and have to reset the switch to restore power.
But a circuit breaker isn't just a piece of your home's power delivery system for you to trip off and flip on. A circuit breaker's primary function is as a safety device. It's cuts power in the house if too much current flows through your wiring at any one time. So, it's important to check the circuit breaker even when power seems to be flowing just fine to ensure the breaker is in good shape. It is recommended that you check your panel every three months or so to keep your wires and your family safe.
If you've tripped a circuit, use the following information to guide you through a full inspection to get your system up and running again.
Step 1 - Initial Check
First, make sure the breaker hasn't just tripped. If any of the switches are in the OFF position, just switch them back to the ON position. If this solves the problem, the breaker works fine. If not, you have to perform more tests to see what the problem is.
Step 2 - Check for a Short-Circuit
Switch the breaker completely to the OFF position, then move it back to the ON position. If it doesn't stay on or there is a humming sound when you switch it on, pull the wire out of the circuit breaker and repeat. If this is the case, there is likely a problem with the wiring.
Step 3 - Testing the Panel
Option 1: Voltmeter
Remove the wire from the breaker. Test the active breaker with the voltmeter. If there is voltage, the breaker works fine, meaning your problem is with the panel, and you will probably have to replace it. If there is no voltage, the problem probably lies in the breaker itself.
Option 2: Wiggin's Tester
Use the Wiggin's Tester attached between the screw and a ground in the panel. If the tester doesn't run, it means that the breaker is faulty and should be replaced.
Option 3: Changing Wiring
Another way to test the breaker to see if it is bad is to move its wire to another breaker to see if it still works. This is the simplest and most effective test. You must ensure that both breakers are off when moving the wire, then turn the new breaker on. If the new breaker still has a problem, this means the wiring is faulty. If the new breaker works fine, this means that the previous breaker had the problem.
Option 4: Ohm-meter
One final test you can do is to test it with an Ohm-meter. To do this, first turn the breaker off, then remove it, turn it back on, and use the ohm-meter to check between its screw and bus clip. If there is a reading above 5 ohms, this means that the breaker is faulty and must be replaced.