How To Troubleshoot a Circuit Breaker

Fixing circuit breaker

Your circuit breaker has "tripped" and you have tried to turn the breaker back on... and it will not stay in the 'on' position, but immediately trips again. What to do next?

This article explains the process of testing your breaker to determine if it is the cause of the trouble or if the wiring to the circuit breaker is faulty.

Step 1

Turn off the main breaker in the home's electric panel. Sometimes their are sub panels in larger homes, especially two story houses, so you need to make sure you have shut off the main 100-200 amp breaker to the whole house.

If you are a little more experienced, you can often find a breaker in the main panel, which controls the sub panel you are working in, and shut this breaker off. This can keep the rest of the home in service while you work in the sub panel. If you have any doubts about which breaker serves the sub panel you are working in, then shut down the main breaker.

Step 2

Access the breakers. You will need to remove the inside breaker cover in the panel (or sub panel) to have access to the breakers. After you open the door to your electirc panel, the breaker cover is attached by a screw at the bottom of the panel. Remove this screw and set aside. Cover should move toward you when you remove the screw. Gently lift up and pull out and down in the same motion.

You will now have access to the breakers. REMEMBER that current is still live to the main breaker, when you are in the main entrance panel, so DO NOT put your hand or any metal tools in the area above the main breaker while you are working in the panel. Also, if you are in a sub-panel that has main breaker inside, follow this same safety rule.

Step 3

With the main breaker off, test the circuit breaker you have the problem with using a test meter (ammeter). Position the test leads (there are two) -- one on the metal screw in the breaker, located below the breaker switch, and the other on the neutral bar inside the panel. The neutral bar will have all the "white" wires terminated in it. You should not read any voltage on the meter (be sure your meter is set to "voltage" and 250 volts when you test).

If your problem breaker is a 220 volt size, it will have a bar (some have double width and single switch) connecting two 110 breakers. You test this breaker by putting both tester leads on the breaker, one lead to each metal screw at bottom of breaker. As an extra safety measure, test each metal screw to the neutral bar. You should not read any voltage in either test. If you do, stop your work and call an electrician.

Step 4

You have determined your problem breaker is safe to remove. The breaker is mounted in a horizontal position with the hot lead terminated on the breaker under a metal screw. (This is normally a black or red wire in residential wiring, on the left side of the horizontal breaker.) Use a flat blade screw driver and turn the screw in a counter-clockwise manner just enough to release the wire. Move the wire away and to the outer edge of the panel.

Step 5

To remove the breaker, take your flat blade screw driver and insert it about 1/8 " deep and behind the breaker you are removing. (Easy does it.) Gently pry up the problem breaker. The screwdriver will move toward the right -- your screwdriver will put pressure on a good breaker on the right side of your problem breaker. Only raise the breaker high enought to grasp with your fingers. You now take your fingers and pull the breaker out toward you, tilting to the left as it comes out and remove it.

Step 6

With the breaker totally out of the panel, push the breaker switch all the way to right and then bring it back all the way to the left. If the breaker switch stays in that position (the on position), your breaker is fine. If it does not stay in that position, then you have a bad breaker and you need to replace it.

Step 7

Take the bad breaker to a big box store and buy a replacement of the same amperage and voltage for your replacement. When home, reverse the above steps and insert the new breaker into the panel. You need to make sure you insert the end of the breaker with the screw in it first, by angling that downward and hooking it under the inside panel rail on the left side.

Once you're sure the new breaker will slide into the gap of the breaker you removed, push down firmly on the right side of the breaker until it seats in the center of the panel. It should be flush with the surrounding breakers.


There are several varieties of circuit breaker/panel manufacturers. Square D manufactures some breakers which are a bit different. GE is now the most prevalent as they bought out Murray some time back. So it is important that you take your old breaker with you to match it exactly.

Ron has been a licensed Real Estate Salesperson, Licensed electrician, Director of Finance for a local non-profit, Systems consultant for Ameritech and Digital Equipment Corporation. View more detail at:
 

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