Carrier central air fail need help

[LeakySeals]

Our carrier central air unit stopped working overnight. Figures, it's the fourth of July weekend, the hottest day of the year, and we have seniors visiting. Was fine all day. Plenty of refrigerant.

Symptoms are burning smell from somewhere inside. No condenser fan. I can hear the compressor faintly attempting to turn over. If I manually turn the fan blades it powers up 1/2 way. But that doesn't help with the cooling. I can still hear the compressor attempting to turn on.

I'm wondering if that's a clue to a power issue, like the capacitor? If there is a way to test it.

 

[Audios]

Sounds like a fan start capacitor to me, I was able to get mine going for the day by spinning it manually and helping it get going. 12$ part for mine. If the top is bulged, which it kinda looks like yours is, theyre done.

 

[mk378]

Check that the unit is receiving the full 240 volts from the house wiring.

 

[Eddie]

The start Contractor. Ed

 

[sloinker]

Start capacitors are a common failure. Hopefully it didn't also ruin the motor if it went unchecked long enough. Locally Menards sells both capacitors and motors in popular sizes. Make sure to pull the local disconnect before doing any service.

 

[Eddie]

Check the Contractor first. Ed

 

[kschachn]

Originally Posted by Eddie
Check the Contractor first. Ed

Do you mean contactor? I agree, we had an insect shell stuck between the two contacts on ours and prevented it from operating.

 

[MParr]

Check the relay switches. Ants and other bugs are attracted to them for some reason and cause big problems with the contacts.

 

[LeakySeals]

Originally Posted by Eddie
Check the Contractor first. Ed

This?

 

[LeakySeals]

Originally Posted by kschachn
Originally Posted by Eddie
Check the Contractor first. Ed

Do you mean contactor? I agree, we had an insect shell stuck between the two contacts on ours and prevented it from operating.

Is this what you mean by contactor?

 

[kschachn]

Yes that's the contactor. Make sure the power is off before you mess with it of course.

 

[LeakySeals]

Originally Posted by Audios
Sounds like a fan start capacitor to me, I was able to get mine going for the day by spinning it manually and helping it get going. 12$ part for mine. If the top is bulged, which it kinda looks like yours is, theyre done.


I was able to turn the fan manually to get it going but it never spun up to its full speed it was only partial. I hear some humming but I also hear what sounds like attempts to start the compressor. I don't know if the capacitor impacts both

 

[FT92]

had that happen a few years ago,,was the capacitor,,,it looked ok but was bad , at times capacitors will swell up but not always,,,be sure the terminals are clean also

 

[WhyMe]

throw the parts cannon at it . change the capacitor. if that don't work change the contact. all that stuff is cheap and goes bad eventually anyways. if sits not bad at least you have a spare. finding these parts on the weekend is not easy

 

[LeakySeals]

Thanks for the input. I reconnected power and without going to the thermostat pushed on the contactor. A slight spark and you could hear the compressor attempt to engage. A manual turn of the fan allowed for a partial spin up. So pushing the contactor gave the same behavior as if I was turning AC at the thermostat. Does that narrow it down to the capacitor?

 

[LeakySeals]

Originally Posted by WhyMe
throw the parts cannon at it . change the capacitor. if that don't work change the contact. all that stuff is cheap and goes bad eventually anyways. if sits not bad at least you have a spare. finding these parts on the weekend is not easy
everybody's closed till Monday. May as well do a Amazon Prime order I see the parts on there

 

[wag123]

The contactor is good if you can hear humming in either one of the motors, leave it alone. You have a bad capacitor (95% odds) or a bad fan motor (5% odds). I have had so many capacitors fail over the years that I keep an extra one, just in case, they are cheap. There should either be 2 individual capacitors (one for the fan and one for the compressor) or a dual-sided 2-in-1 capacitor (like what is in yours). You can substitute individual capacitors for your dual-sided capacitor if you can't find a suitable dual capacitor at the hardware store today (and you don't need to go back later and replace the individual capacitors with a dual capacitor).

 

[sloinker]

Like I said, Menards and maybe Home Depot/Lowes will stock common capacitors, even split style like yours. Make sure that you don't mix up the two motors when assigning a split cap.

 

[LeakySeals]

Should I short out the capacitor with a screwdriver in case it's storing a charge

 

[wag123]

Originally Posted by LeakySeals
Should I short out the capacitor with a screwdriver in case it's storing a charge

You can just to be safe, but since it is working in an A/C circuit, it shouldn't be storing a charge.
The 60/5 uf (aka mfd) is a common motor run capacitor and 370vac is a common voltage (but you can go higher, like 440vac). 60mfd is the compressor side and 5mfd is the fan side. They are under $20.