What should the oil differential pressure be on a copeland discus compressor? I just replaced one today (grounded) and the new compressor will unload when still having a call for y2. Starts loaded with no voltage to unloader and after running about five minutes, cylinder unloads. I am thinking it has something to do with the oil pressure but do not know what the range is. This is a 15 ton split york. Oil burnt so I installed suction shell. Going back tomarrow to replace oil, suction filter, and liquid line drier again. Also the suction screen on the inlet of bad compressor was completly plugged. Currently I have 35 delta P oil (loaded and unloaded). Any suggestions?