WD12 good temps?

[billy1ear]

I have been messing a wd12 for a while and have finally brought it into the house to use.
I got a new thermostat that you can adjust the differential on as the original was cycling at 39 to 53 before it came on.
The compressor deck or skid is not original to the machine but i am sure it is an old +20 yr old unit (Tecumseh AE37300AA).
Right now i am cycling between 37 and 41.
36 deg is the lowest i have been able to get my temp to get, this is only if the compressor runs several hours without shutting off.
The compressor runs more than it is off, is that normal?

It uses Freon 12 and pressures are about 242/40 and the gaskets and insulation are all new and the coils are clean with no ice forming on the coil or plumbing.

So in a 75-78 deg house should my compressor be on more than it is off to maintain 37-41 or do I have a problem?

Thanks in advance...

[kbareit]

Sounds like it is overcharged. A system at 75 to 78 degrees ambient temp should result in a high side pressure of 125 to 132 psig. and the low side pressure should be around 20 psig giving you a coil temp of around 20 degrees.If it still is running on R-12. At your current low side pressure of 40 psig your coil temp is 36 degrees, the coil temp needs to be around 15 degrees lower than the air temp of the cooler known as the temp difference. If you have any questions contact me and I can help.
                                                       Thanks,Ken