Technical Systems M# 20A0CS40 460 VOLT Condenser, Dunum Bush Air Handler very old. Copeland compressor model 6DS3R40M0-TSN-800. epr, suction acculator, reciever and hot gas defrost.

I am running 40 # suction 225# head pressure. 11 sc and 15 sh. 2 unloaders. Room temp to maintain 35 degrees. I have 2 systems and both are doing same thing.

My problem is loss of oil pressure. Solenoid holds on pump down, compressor valves do not leak by. 1 Unloader unloaded all the time the other unloader loads and unloads. oil foaming slightly when fully unloaded and a lot of foaming when partial unloaded. crankcase hot.

Any suggestions. Are these comprssors use hot gas bypass can you change to suction cutoff. i am stumped. Oil pressure never gets over 15# net oil pressure then will go to 10 and 5 at various times.

Any suggestions would be appreciated.