Is A/C compressor affected by outside temperatures?

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Originally Posted by Johnnyma45

So to clarify, the fan is spinning well right now. The video was from the previous issue (which the capacitor fix took care of). It has not made that sound (and the fan has been working well) since the fix. If the motor is still bad, would it cause the current issue of shutting off the compressor only during a couple of the afternoon hours?

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OK, I now caught the time sequence...sorry I missed it earlier. I was completely focused on that video.

As to your current problem, your previous problem may have led to the one you have now. The compressor motor in your video stopped running only when the internal overload inside the compressor opened. This was because the fan had stopped running. You then had the tech fix the fan. And now the unit cools except in the hottest part of the day.

Which tells me that the internal overload inside the compressor may have been weakened by your previous episodes of the fan motor locking up and causing the compressor to become very hot.

If the outdoor coils are dirty, you might try getting those cleaned to see if you can coast through the hot afternoons without the compressor cutting out. If they are clean, and the refrigerant charge is right, you may be on the hook for a new compressor or unit.

Thanks Shophound, that's what I suspected. I had a tech sent by my home warranty company and after watching the video, he stopped at fixing the fan. I will look to clean the coils and hope that that will do it.

If I do have another tech come out and I explain the issue, are they typically able to detect a weakened/dying compressor if that is indeed the problem? I'd like to guide them so there's not a repeat of the last time, when he didn't find anything due to it "working".

There are tests available that can inform a person how healthy a compressor might be, but the effectiveness of those tests toward this end depend on at least two factors: a) interpreting the results of the tests correctly, and b) end user willing to pay for the tests if an extra charge on top of a service call is presented.

So what are the tests?

a) Megohmmeter - aka "megger", not often used in residential work but can inform the tester as to the health of the compressor motor windings.

b) Acid and moisture test - informs the tester if the oil in the system is acidic and/or contains moisture. Acids form in compressor oil either due to moisture or excessive heat, or both. Elevated levels can sometimes be managed by changing the liquid line drier in the system.

In your case, if the internal overload has weakened due to the recent stress it suffered from the failed fan motor, you could also have elevated acidic levels in the compressor oil. Typically, not many homeowners are willing to pay for efforts to prolong the life of a compressor potentially at risk, but some may. From that point it's a matter of finding a tech who can properly administer and interpret the tests, and inform you, the end user, what those tests indicate as to the health of your compressor.

This is why I recommend for you to ensure the condenser coils are clean. You want to reduce stress on the compressor by enabling it to get rid of heat more effectively. That's what clean coils can do, and may enable you to get through the hot afternoons without the compressor cutting out on overload.

Quote:

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Originally Posted by Shophound

There are tests available that can inform a person how healthy a compressor might be, but the effectiveness of those tests toward this end depend on at least two factors: a) interpreting the results of the tests correctly, and b) end user willing to pay for the tests if an extra charge on top of a service call is presented.

So what are the tests?

a) Megohmmeter - aka "megger", not often used in residential work but can inform the tester as to the health of the compressor motor windings.

b) Acid and moisture test - informs the tester if the oil in the system is acidic and/or contains moisture. Acids form in compressor oil either due to moisture or excessive heat, or both. Elevated levels can sometimes be managed by changing the liquid line drier in the system.

In your case, if the internal overload has weakened due to the recent stress it suffered from the failed fan motor, you could also have elevated acidic levels in the compressor oil. Typically, not many homeowners are willing to pay for efforts to prolong the life of a compressor potentially at risk, but some may. From that point it's a matter of finding a tech who can properly administer and interpret the tests, and inform you, the end user, what those tests indicate as to the health of your compressor.

This is why I recommend for you to ensure the condenser coils are clean. You want to reduce stress on the compressor by enabling it to get rid of heat more effectively. That's what clean coils can do, and may enable you to get through the hot afternoons without the compressor cutting out on overload.

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Thanks for the detail and the descriptions. I've read that spraying the coils from inside the unit (fan guard removed) with water is sufficient? No cleaning agents/soap needed?

Do not let anyone use a power washer to clean your condenser. Power shut off and as you've described is best.

Thanks for the continued help Shophound, it is greatly appreciated. On Tuesday the condenser shut off once more, a bit later in the day (6:30-7:30pm) but still followiing the high temp pattern. I'll wash it this weekend and hope for the best.