rdmsqito
07-09-2007, 08:26 PM
Hey guys, has anyone ever seen this?
I have a 2HP Copeland semi-hermetic compressor that runs well and cools great. Problem is when the compressor shuts off pressure is going backwards through the compressor from high side to low side causing the unit to "dance" as it rotates in reverse. When the thermostat closes the solenoid the unit pumps down properly, the pressure control is shutting the compressor off at about 0 psi as it should, then the dancing starts. First thought was maybe electrical but cutting the power does nothing to stop it. It will either stop on its own after a minute or so or raise the low side pressure high enough that the pressure control starts the comp again until it pumps back down to 0 then starts all over. Closing the discharge valve while it's dancing will make it stop, so it's definately refrigerant passing back through. Thought maybe bad valves but compressor will pull 18inhg vacuum by itself. Any thoughts?
Unit is R408A, charge is good running 20 psi low/225 psi high. TIA
-Vinny
I have a 2HP Copeland semi-hermetic compressor that runs well and cools great. Problem is when the compressor shuts off pressure is going backwards through the compressor from high side to low side causing the unit to "dance" as it rotates in reverse. When the thermostat closes the solenoid the unit pumps down properly, the pressure control is shutting the compressor off at about 0 psi as it should, then the dancing starts. First thought was maybe electrical but cutting the power does nothing to stop it. It will either stop on its own after a minute or so or raise the low side pressure high enough that the pressure control starts the comp again until it pumps back down to 0 then starts all over. Closing the discharge valve while it's dancing will make it stop, so it's definately refrigerant passing back through. Thought maybe bad valves but compressor will pull 18inhg vacuum by itself. Any thoughts?
Unit is R408A, charge is good running 20 psi low/225 psi high. TIA
-Vinny