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AC Compressor keeps tripping breaker.

12852 Views 7 Replies 7 Participants Last post by  J. V.
As the title says, every few hours our Compressor trips... And we have to go out and reset it. I assume this is potentially dangerous, and would like to fix it.

Before I go and spend a ton of money on a professional, is there anything that can be done by an "experienced-amateur"?

Thanks in advance.
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Check for a loose connection at the CB that is heating the CB and fooling it into thinking there is too much current. If there are numbers on the CB, post them.
Before I go and spend a ton of money on a professional, is there anything that can be done by an "experienced-amateur"?
Probably not. You can visually inspect all associated wiring/connections on both ends (panel and unit) but you will need at leat an amp meter to do any electrical testing.

The condensor has a compressor and a fan motor. Either one can and will malfunction and cause a breaker to trip. If you can narrow the problem down to the fan motor, it is not a difficult repair/replacement. In my experience, If it's not the wiring/components, the fan motor is generally the culprit.

If you can narrow the problem down to the compressor, call someone.
If the breaker is old or weak, nuisance tripping can be a problem.

Replacing the errant breaker will solve such problems if that is the culprit. But before you replace that breaker, check the nameplate of the outside unit to ensure you have the correct size wire, and breaker to start with.

You are looking for the following information (Or similar wording):

"Minimum circuit ampacity" <--- this helps to determine the wire size needed for the compressor.

"Maximum breaker size" <--- this determines the largest size breaker you can safely use for the unit.

Report back with your findings.
Notice the OP didn't say anything about the CB tripping. I'm guessing he means the overload on the compressor itself. Probably time for an A/C service call and/or a new compressor.

Edited: Didn't see the part in the title about the CB. Anyway, old compressors are sometimes hard to start. A "hard-start" kit might solve the problem for a few years. This is just a large start capacitor added to the compressor that reduces the inrush current to the compressor. They cost about $15 and a DIY can install one (just watch getting shocked by the stored energy in the existing capacitor).

Mark
Get a current meter (clamp on) and have someone measure the current at a peak use time. This will indicate if you indeed have an overload or something else. How long has this compressor run without problems? Does it do it at a certain time of the day? When did this problem start. Does your compressor start unloaded or loaded? Compressor starting draws alot of current. Many more times than the FLA nameplate amps. Are you resetting the breaker or the compressor itself? Whats the Hp, RPM, FLA and voltage?
I just went through a similar problem with my capacitor start table saw motor.
The start contacts inside the motor had a carbon buildup on them.
I cleaned them up by filing the carbon off and resolved the problem.
I just went through a similar problem with my capacitor start table saw motor.
The start contacts inside the motor had a carbon buildup on them.
I cleaned them up by filing the carbon off and resolved the problem.
Filing contacts is not a very good idea. It removes the thin copper or similar precious metal from the contact mating surface. Yes, for a temporary fix. I have found that a simple pencil eraser does a good job and does not remove as much precious metal. You would very surprised at how well an eraser works. It will not repair deep pitted contacts. But is excellent for surface cleaning. :thumbsup:
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