Intermittent 24v to outdoor unit

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  #1  
Old 09-20-18, 05:09 PM
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Intermittent 24v to outdoor unit

Hello,

I am having an issue where the 24v to the outdoor unit is cutting out sometimes. It is unusual in that it can be fine for a few weeks, then it will be sporadic causing the contactor to go on/off, then it will cut out entirely for several days, then at some point I will try to turn it back on and it will come back and be fine for a few weeks. The pattern is very odd. If it were just gone completely I could troubleshoot it easier, but since it wants to start working again it has me scratching my head.

I guess the ultimate question is then, what component that involves 24v can go in-and-out sporadically like this? What exactly should I be testing? It seems like maybe a component is slowly dying.
 
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Old 09-20-18, 06:10 PM
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May have a condensate overflow or wet switch installed inline somewhere.
 
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Old 09-21-18, 12:35 PM
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Welcome to the forums.

Are you actually checking the 24vAC with a meter or just assuming it's cutting out ?
Your problem also sounds like it could be a low refrigerant issue.
 
  #4  
Old 09-21-18, 04:00 PM
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I don't see an overflow switch and the drain line seems to be flowing fine.
I measured the 24v with meter by putting one probe on the right terminal of the contactor and the 2nd probe on the left side.
I don't think there is a switch that would turn it off if refrigerant were low and It seems to run cool when it runs, but maybe it is right at the threshold of being considered low and keeps fluctuating up and down. Is that possible? If so, where might I find that switch responsible for disabling it when that happens? Usually outside or inside around the furnace area?

Thank you
 
  #5  
Old 09-21-18, 05:07 PM
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I don't think there is a switch that would turn it off if refrigerant were low
Usually there is.

When checking for 24vAC...... you need to check where the wires from the thermostat connect to that condenser. Usually in the wiring access area where all the wiring connects. The low pressure and other safet switches are inside the condenser..... between where the wiring connects and the contactor.
 
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