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Lurch77
Premium Member
join:2001-11-22
Green Bay, WI

Lurch77 to tomupnorth

Premium Member

to tomupnorth

Re: Capacitor / Compressor Dead

You need to remember that a hermetic compressor, like those in a residential system, are completely sealed. There is no place to reject motor heat except into the refrigerant. If the system is low on refrigerant you lose much of the motor's ability to reject the heat. And as garys_2k said, oil return becomes problematic with low refrigerant. These are just two problems that can be detrimental to a compressor if ran with low refrigerant. Nearly all commercial and industrial systems have a high and a low pressure safety in play. Many newer residential systems do as well. They are cheap insurance. If you don't have a low pressure safety on your system, ask you tech about it next time he is out.
tomupnorth
join:2005-01-14
UpperMidwest

tomupnorth

Member

said by Lurch77:

You need to remember that a hermetic compressor, like those in a residential system, are completely sealed. There is no place to reject motor heat except into the refrigerant. If the system is low on refrigerant you lose much of the motor's ability to reject the heat. And as garys_2k said, oil return becomes problematic with low refrigerant. These are just two problems that can be detrimental to a compressor if ran with low refrigerant. Nearly all commercial and industrial systems have a high and a low pressure safety in play. Many newer residential systems do as well. They are cheap insurance. If you don't have a low pressure safety on your system, ask you tech about it next time he is out.

Hmm I will have to look and see if my 10 year-old Carrier has a low pressure safety on it.

At the risk of hijacking this thread, you guys can probably answer a question for me: Is there ANY OTHER POSSIBLE explanation for "losing refrigerant" than that there is a leak somewhere? This business of "oil in the system" makes me wonder if the problem I am having, which is to have to add refrigerant every couple of years, might not be a leak but rather "too much oil in the system" at original commissioning or something.

The only info I gleaned from my tech when he was here last, was he said "have your system checked again in the spring, before cooling season starts, because in the Winter when the heat pump cycle is reversed, the fan coil becomes the High Pressure side, and that is when you'd be likely to lose freon if you only have a very tiny leak up there (in the attic)".

Lurch77
Premium Member
join:2001-11-22
Green Bay, WI

Lurch77

Premium Member

It's doubtful you have more oil than needed, unless someone has been adding it over the years. The compressors are properly filled at the factory. If you are down on refrigerant, you have a leak.