# a/c unit tripping circuit breaker



## SecretSquirrel (Jun 22, 2007)

Overcurrent (high amperage) is why the breaker is tripping.

Is this a window unit or a central AC unit?


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## StrandedJoe (Jul 12, 2007)

This is a central unit.


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## SecretSquirrel (Jun 22, 2007)

I'm sure some HVAC Pros will step in here with a better analysis but my guess is the compressor is starting to malfunction, for whatever reasons. If you can post the age, make & model of the unit then that will help others come up with a diagnosis.


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## StrandedJoe (Jul 12, 2007)

Thanks for the reply...

I don't have the make or model handy right now, as I'm at work. I'll get that information later. I can tell you, though, that the unit is less than 3 years old. We experienced the circuit breaker tripping one time, about a month ago. Then yesterday it started to trip the breaker on a regular basis.


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## SecretSquirrel (Jun 22, 2007)

There's always the possibility of the feeder wiring having a ground fault or a short. Can you pinpoint any repetitve environmental conditions that occur around the time the breaker trips? Is it raining or extremely hot or anything else come to mind?


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## StrandedJoe (Jul 12, 2007)

When it started doing it yesterday, it was raining heavily for the first time in months. However, it is not raining now, and it is still tripping. We have had very hot temps (in the 90s), and basically dry until the last few days.

How would I check the feeder wiring?


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## SecretSquirrel (Jun 22, 2007)

You could start by visually inspecting the wiring and making sure all the termination points are secure. Look for knicks, scrapes, or any discoloration of the insulation due to overheat. Look for arc points close to the wiring in all the junction boxes and connectors. If you know how to use an ohm meter then you could disconnect the wiring from both ends (or turn off the disconnect outside at the compressor) and see if there's any measurement to ground or between conductors. The best way to check it is have an electrician "meg" it out using a megohmmeter to check for ground faults and shorts. Please exercise caution if you choose to pursue this yourself by turning off the breaker, wearing insulated shoes... don't stand in water, you know the common sense stuff. 

Another question... does the breaker trip randomly or is it when the compressor or fan kicks in?


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## StrandedJoe (Jul 12, 2007)

It appears to happen after the compressor's been running for a little while.


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## SecretSquirrel (Jun 22, 2007)

You could also check to see if moisture is a problem in the control panel at the compressor. This all kind of leads back to the compressor or some related control that is causing the trip. I'm out of ideas so hopefully someone else will jump in here with some fresh thoughts. It could be anything from a sticky bearing on the cooling fan to an electrical fault of some sorts. Good luck and I hope you get it resolved in fairly short order.


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## StrandedJoe (Jul 12, 2007)

Thanks for all the input. I will check into a few of the suggestions today when I get home. 

As for getting it resolved in short order, that makes two of us! :wink:


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## StrandedJoe (Jul 12, 2007)

Update:

I replaced the contactor on the unit. It was faulty. I also had to replace the circuit breaker, b/c it had overheated and was still shutting off. It's been working fine, so far. I'm keeping my fingers crossed! 

SecretSquirrel, thanks again for your inputs!


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## SecretSquirrel (Jun 22, 2007)

Joe... glad you got it worked out although I don't feel like I did much to help the cause. I guess sometimes it's just good to talk it through.


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## airtrackinc (Feb 12, 2014)

sound like some ware in the AC electrical system have short-circuit, contact your AC technician for proper trouble shooting


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