was wondering if I could get advice from someone here on what the problem with my system might be?
The problem sounds simple: the warmer it is outside, the longer it takes my unit to actually start cooling once commanded to.
My unit is about 5 years old. The manu is Fedders. The compressor is a Copeland.
Power is getting to the condenser (condenser fan is running) and compressor (I've measured at the terminals of the condenser unit and at the actual terminals to the compressor).
The issue starts becoming pronounced around 68F. Below that the compressor engages only a minute or two after commanded to (which I believe to be weird as well, but at least it eventually starts). Above 68F the problem gets worse. At about 77F it can take 30-60 minutes before the compressor actually starts running (the condenser fan is running the whole time). Above 86F it can take many hours before the compressor actually starts running.
Direct sunlight has an effect, if it's 77F, but the sun is shining on the condenser the compressor will take longer to start then if it's overcast.
Once the compressor HAS started, it runs and cools without any issues. It will run all day, no matter what temp outside or how strong the sun is shining. I've gone so far as to just turn it on in the morning and let it run all day.
I've replaced the starting cap, no difference.
The problem has been the same over the past 3 years (we moved into the house 3 years ago), I haven't seen the problem getting worse.
I've done a ton of searching. The most common solution people have is a hard start kit. Would this solve this?
Fundamentally I'd love to know what is causing this problem. I know that compressors have overpressure and overtemp switches in them. Is it possible the overtemp switch in mine is faulty (I know it's sealed and not servicable).
Would an undercharge or overcharge of the system explain these symptoms (some google searches say yes)? I have had the system looked at with no recommendation or explanation other then "replace it all". I'd like to at least understand what the problem is other then a stab in the dark solution of full replacement.
While HVAC is obviously not my profession, I am very experienced in related fields and would appreciate if someone here would be able to guess what is causing my problem?
Thanks in advance!