I have a single phase copeland compressor that runs fine for about a half an hour then the high side goes to 275 and the low side starts to go down to 15 psi. it's like try to run on vacuum but then it shuts off of course. Condenser is clean and it has capillary tube.
when the pressure is running right it stay around 250 high side and 35 degree coil. I tried to get it to 40 degree coil but the head pressure goes to high. Do you I have too much on it? the temperature outside is 92 and is a r-22 unit. any help would be appreciated