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A/C Compressor Cap Question

Posted: Sat May 19, 2012 5:36 pm
by psycho
I have a 40/5 uF 440 cap. When I shake it I can hear liquid movement. I would think that this would mean that there is air in there and I didn't think there was supposed to be any air in it. I am not certain but it MIGHT be slightly bulged on the ends.

Any idea if I should be able to hear this sloshing???

Thanks,
Kevin

Re: A/C Compressor Cap Question

Posted: Sat May 19, 2012 10:22 pm
by frhrwa
if its bulging, I'd take that as a hint to replace, as to sloshing, I've never heard a cap slosh.. new one on me..

Re: A/C Compressor Cap Question

Posted: Sat May 19, 2012 10:30 pm
by psycho
I am going to just replace it.

Thanks!

Re: A/C Compressor Cap Question

Posted: Sun May 20, 2012 3:10 pm
by dacflyer
might be cheaper to get 2 separate caps, then a dual cap.. from my exp. sometimes.

Re: A/C Compressor Cap Question

Posted: Sun May 20, 2012 3:20 pm
by Janitor Tzap
I agree with frhrwa,

Replace it.
The sloshing sound is because the seal on the capacitor has failed.
This allowed oil that was inside it to escape, either by vaporizing when it over heated.
Or just leaked out of the capacitor from where it bulged and burst.
Look in the A/C unit for oil.
NOTE: If the capacitor is older than 15 years, it may have contained PCB's in it!
So, If find oil in the A/C unit, Use rubber gloves and disposable rags to clean it up.
Place the used rags, and rubber gloves in to a resealable plastic bag,
and take it too your local hazardous waste disposal site.


Signed: Janitor Tzap

Re: A/C Compressor Cap Question

Posted: Sun May 20, 2012 5:19 pm
by psycho
I don't see any oil in the unit but I will make sure I am careful!

Thanks again!
Kevin

Re: A/C Compressor Cap Question

Posted: Mon May 21, 2012 1:43 pm
by haklesup
No oil, that's good. PCB oils are so stable they don't even evaporate but more common mineral oil dielectric will evaporate and leave little trace over time.

AFAIK, the PCB dielectric oil was only ever used in industrial applications such as those used by the power company. It was used in transformers and capacitor banks as a dielectric and a coolant. It was desireable due to its stability which is what made it such a enviornmental toxin in the end.

Re: A/C Compressor Cap Question

Posted: Mon May 21, 2012 4:27 pm
by psycho
Ahhh. I was wondering about that. I got a new cap today and I will have it all put back together soon :)

Thanks,
Kevin