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I have a circuit breaker that keeps tripping. It doesn't trip right away, but several hours after turning back on, sometimes a day later.

Nothing has changed on the circuit that's tripping.

How can I determine if it's the breaker that's bad or if it's a short somewhere?

Thank you in advance!

  • Do you have a clamp-on ammeter? – ThreePhaseEel Jul 19 '17 at 1:41
  • I don't. Just a regular meter. Do you think maybe I'm drawing too much current and the breaker is just doing it's job? – Adam sperber Jul 19 '17 at 1:52
  • Perhaps -- can you get a clamp-attachment for your meter, or perhaps a nearby tool-rental place will rent you a clampmeter for this? Using a clamp ammeter will allow us to see if the loads are normal or actually enough to make the breaker trip eventually. – ThreePhaseEel Jul 19 '17 at 1:57
  • Also, what all is on said breaker? – ThreePhaseEel Jul 19 '17 at 1:57
  • First of all, thanks for taking the time to assist me. I can get a clamp on meter inexpensively on Amazon and test it. – Adam sperber Jul 19 '17 at 1:59
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First simple answer, you may want and or need to call an electrician since a short can lead to a fire.

Simple things you can do first:

  1. Make a list of EVERYTHING that is on the breaker downstream

  2. Add up all of the rated labels for every component

  3. Make sure you truly have EVERYTHING listed. Keep in mind, chandelier lights, with 12 bulbs in them, and 40w each bulb is actually pulling 480W.

4.For anything that is a major appliance or heavy motor or heat load add 25% to its label for good measure

  1. Total the items up, if you are over 75% of a 15AMP circuit for example, you should really re-balance your loads. This is really a safety concern and the fact that it worked for x amount of time and now is causing issues is a real concern. Over time, drawing too much current from a circuit causes the wires to expand and contract, and can even break down the metal wire & contacts, from burning and oxidization. Also, plastic parts that hold those metal contacts can melt, warp, or become brittle and break. Thus, your short *(or high current) situation.

  2. Are any of the items plugged in or connected via cords exposed to people or pets? Check the cords for frayed or broken conductors, feel exposed cords for any warmth - the should not be hot

  3. Of the list of items you made, are any on a duty cycle? Like a sump pump, a fridge, an A/C, an outdoor flood lamp?

  4. Has any part of the home been remodeled or have any switches been intermittent at all? if so, then they need to be inspected or replaced, or the workmanship checked.

  5. Any of the items on the list themselves behaving erratically? Any unusual smells from a Fridge or an A/C etc can be signs of a fault in the appliance/component.

If these things all check out, and the load on the breaker is not at 75% or greater before any changes are made, then it is probably a bad breaker. They can go bad! What is the age of the home and the wiring?

A side note: if the house has aluminum wire or has been remodeled at all, have a professional check it. There are specific methods that can be employed to keep aluminum wiring safe but it has to be done correctly. Conversely, if something was remodeled, they should own/warranty any work they have done.

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