A/C Compressor problem


I have a 5 year old Trane XL14i - 3 ton I think. Yesterday I noticed it getting warm and the blower was running, but the compressor and fan were off. The contactor was engaged and power was getting to the unit.
I turned everything off for about 10 minutes and then back on. Its been working fine for 24 hrs. and register temps are right where I expect - 62F at 110F evap temp and 90F outside temp. I'm wondering if this is a fluke or if I have a more serious problem. What can I check?
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Bad contactor. If fan and comp are both off, the likely culprit is the contactor.
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Christopher A. Young
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On Jun 1, 9:30 am, "Stormin Mormon"

I agree that's the most likely. If you were able to tell it had power was that with a meter? Next time it happens check the other side of the contactor for 240vac. While most techs will replace a contactor because they don't want a return call, it is possible to repair them. Usually it is pitted and worn contacts. You can clean them up with a small file.
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I was thinking run cap, until I read both fan and comp were out. The "turned off then on" was the other factoid.
Hope the OP is kind enough to follow up, let us know what was the actual problem.
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Yes, I checked power with a meter, but it was only incoming power and not outgoing from the contactor. The contactor was engaged and humming, so I assumed it was the cap, but then the fan would have been on. I just droppd the ball there.
As a precaution, I'll clean the contacts. I'll be sure to post again if it stops again.
Thanks all.

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On Jun 1, 8:58 am, snipped-for-privacy@gate.net wrote:

Please turn off the power before you operate on the contacts.
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On Jun 1, 9:58 am, snipped-for-privacy@gate.net wrote:

The caps practically never cause intermittent problems. I can see how you might cycle it once before checking everything and then when it started that was the end of troubleshooting. I hate intermittent problems on any thing as they alway seem to go away right after I take the cover off.
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snipped-for-privacy@gate.net wrote:

OK, you found the problem. Power in and no power out? There's your problem, a bad contactor.
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Sorry, I was not clear. I did NOT check outgoing power. We were on our way out of the house and I was rushed, so I just checked to see if I had 220V coming in and then assumed all was OK.

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On Jun 1, 7:56 am, snipped-for-privacy@gate.net wrote:

A few years ago my outside unit fan wouldnt kick on first try, I think the unit was making some noise, I powered off and on a few times and the fan came on, the tech came out and tested and replaced the capacitor and said if I had left it for a long time trying to start I could have burnt out the unit, its been fine for 6 years since, find what is wrong before it leads to a bigger issue, maybe its the capacitor
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The op said that both the fan and compressor would not start. That makes the contactor a lot more likely to be the culprit.
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On 6/1/2010 7:56 AM, snipped-for-privacy@gate.net wrote:

I've had bugs "insects" get into contactors and keep them from closing completely. Turning off the power to the condensing unit and manually working the contactor will usually get rid of the dried up insect parts without having to resort to contact cleaner. A fresh gooey bug is a lot harder to clean out. I actually have had to clean out whole ant colonies that have taken up residence in the control compartments of condensing units.
TDD
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