Is this capacitor failure?


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Old 09-12-11, 11:16 AM
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Is this capacitor failure?

My Sears window AC is just two seasons old but this year its Delta-T has been, at best, 12 degrees F. Last season I could turn the same room into an ice box. I posted here a while back asking for help souping it up but I guess my questions were too vague and no one could help. One of the possible causes I'd wondered about was a weak capacitor. I didn't -- still don't -- know if they can go bad gradually or if they always fail totally all at once.

Anyway, yesterday it stopped producing any cooling whatsoever and I no longer hear the compressor kick in. I can twist the temperature knob seven ways to Sunday and there's no change in the sound unless I twist it to the "Fan only" position.

Does this sound typical of a failed run capacitor?

If yes, is this something a reasonably mechanical guy with more tools than skill could perform? If yes, is there likely to be more than one capacitor, or something else I might confuse for the failed capacitor?
 
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Old 09-12-11, 02:23 PM
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It does not sound like a capacitor. If you have lost capacity over the course of 2 years, and now the compressor does not run, I would bet you have a refrigerant leak and now the compressor is failed.
 
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Old 09-12-11, 05:50 PM
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Thanks for that, hvactechfw. I removed the capacitor and checked the resistance between the common terminal and the 'herm' terminal. It checks 87.3 ohms which I take to mean it ain't the capacitors fault. Would that be your take, too?
 
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Old 09-12-11, 05:52 PM
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no, that would not be my take because that is not how you test a capacitor. You would need a meter that checks capacitance. (micro farads)
 
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Old 09-12-11, 06:21 PM
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Hmmmm ...my multimeter seems to have lost all its farads. I knew I should've bought a fluke.

Is that the sort of thing they will test for the customer at an HVAC parts store?
 
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Old 09-12-11, 06:22 PM
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probably not. A capacitor is very cheap. If you really want to just by one for less than $10.
 
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Old 09-12-11, 06:58 PM
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Cheap is the name of the game. If it's not the capacitor, the a/c is toast so I'd sooner put that $10 to the purchase of a replacement than buy a cap I might not need.
 
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Old 09-12-11, 07:11 PM
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Now that is cheap!!!!!!!!!!!!!!
 
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Old 09-12-11, 07:34 PM
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Thanks for the positive reinforcement but if I weren't hurting for cash I'd have thrown the unit in the trash and bought a replacement back last spring when I discovered it could only manage a Delta-T of 12F.
 
 

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