# Burned wire on ac capacitor common



## Elkypro (Dec 23, 2011)

Ok. Getting warm this season and decided to check the ac to make sure it works. The past couple years I have had the ac not work upon first startup. The first year was a leak in the coil. It just popped when I turned it on and everything leaked out. The second year the unit turned on but no cold air. I replaced the capacitor to no avail. Called a tech and he pressure tested the entire coil, which was fine, and found a small leak in the valve where someone had tried to plug it years before it looked. He replaced the valve and that portion of the pipe. Everything worked perfect for the whole season. This year I turned it on and no cold air. Opened the side and saw the burned connection on the common. Replaced the wire and bought another new capacitor. Now the unit still does not blow cold air but it the fan runs but I cannot tell if the compressor is running or not. The pipe does not get cold at all. Maybe I re-wired it back wrong? 
The compressor is a copeland. 
Thank you in advance.

http://i.imgur.com/7pcGt.jpg

http://i.imgur.com/uUIWG.jpg


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## hvac5646 (May 1, 2011)

If the comp is running then you may have a no refrigerant in the system.

Did you say you can feel air coming out the ducts?


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## Elkypro (Dec 23, 2011)

Yes, there is the normal amount of air coming out of the ducts.

What would be a good way to see if the comp is running? Take off the fan unit and turn it on?


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## thermal-medics (Feb 11, 2012)

*check this*

you can hear the compressor running when the outdoor fan motor kicks on. if its a copeland scroll then you should hear the hi pitch at start up. you can find out quickly if you take an insulated screwdriver and push that plunger on the front of the contactor - *holding the insulated handle*. then you should hear both come on.

just make sure you discharge that capacitor if you are going to touch any wires after testing it - they pack a punch.. i know this.


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## heatingman (Mar 17, 2012)

thermal-medics said:


> you can hear the compressor running when the outdoor fan motor kicks on. if its a copeland scroll then you should hear the hi pitch at start up. you can find out quickly if you take an insulated screwdriver and push that plunger on the front of the contactor - *holding the insulated handle*. then you should hear both come on.
> 
> just make sure you discharge that capacitor if you are going to touch any wires after testing it - they pack a punch.. i know this.


 it could be that your compressor is bad you could ohm out the windings take the plug off the compressor and ohm out start, run, terminals that will let youo know if it is actuall compressor if you run low on charge you will experience freezing of a/c


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## Elkypro (Dec 23, 2011)

Thanks for the tip of the contactor. I pushed in the plunger for a few seconds and the compressor came on just fine. So time to call the hvac to find another pesky leak


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## beenthere (Oct 11, 2008)

I don't see that you have a pressure switch that could keep the contactor from pulling in.

You may not have 24 volts going to the outdoor unit.


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## Elkypro (Dec 23, 2011)

beenthere said:


> I don't see that you have a pressure switch that could keep the contactor from pulling in.
> 
> You may not have 24 volts going to the outdoor unit.


I'm sorry, I am very much a laymen when it comes to electrical work. Would you mind explaining if that is good/bad as well as what the difference that would make? 
Thank you


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## beenthere (Oct 11, 2008)

Could just be the the contactor is bad. or that you don't have 24 volts to the contactor from the thermostat.


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## thermal-medics (Feb 11, 2012)

*Elky*

You are probably right on the loss of refrigerant. All you started with was as visual inspection of the run cap and found a burned terminal. You replaced and confirmed the outdoor fan motor and compressor came on. 

1. if you leave the unit off for an hour or so the pressures will stabilize and you should not have a low/high pressure cut out.

2. If you have the whole shebang working in unison compressor, outdoor fan, indoor blower and you can feel the refrigerant pipes and they are lukewarm - both of them- than I would be sticking to your gut instint instead of just swapping parts if you are not into working with a voltmeter.

I would leave it off until you can verify the refrigerant is still there and not keep running it or the repair prices will add a 0 on to the final tab in a hurry.


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## Elkypro (Dec 23, 2011)

Thanks for the responses guys. Much appreciated!


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