DWM Copeland compressor diff oil pressure tripping

Hi,
Please someone suggest on the following problem.

DWM Copeland compressor is tripping with oil differential pressure. There is diff pressure switch installed on pump which operates with the differential of Pump outlet pressure & crank case pressure. This compressor was not run for longtime, heater is in ON condition, oil level ok,

when started the unit, oil pr build upto 120psi for sometime & slowly drop down to nearly 60-70psi
and tripping. suction pressure id around 55psi.

diff pr setting is 0.65 bar i.e 9.2psi (factory set)

pump is in good condition.

what could be the reason for drop in oil pressure? is there oil dilution or some other reason. what is required to keep the unit ok?

pl suggest
regards
tvrao

Hi there , could the oil strainer be blocked? something to check.

i am with Andy, if compressor was shot for a long time, it will only do it good to replace oil and cleat the oil strainer, typical for slow oil pressure drop.

also comfirm the crankcase heater is ok, moniter the acutal oil pressure, the delay should be usually 90-120 seconds , also the correct oil level in the sight glass is important too, liq slugging can wash oil out the sump