Chiller problem

[Dheeraj]

Hi! We are facing an unusual problem with McQuay Centrifugal chiller of 600T. These chillers have a forced feed lubrication oil pump. We are facing a problem of unhealthy oil pressure.
The chiller was under breakdown due to bursting of oil pump heater, leading to damage of Al bearings of compressor. We changed the bearings. During initial oil pump start(compressor being idle) with a system pressure (suction pr) of about 1kg the pump delivered a net pressure of 10Kg. But with full refrigeration charge i.e. with 4~5 Kg of system pressure the net oil pressure dropped to 5Kg/cm2. This seems to be a very strange problem. Can anybody guide me on probable cause.
The oil being synthetic oil with 46 viscocity and R134a refrigerant.

[imran ansari]

go for oil analysis first..... instal regulator valve also

[Dheeraj]

There is an oil pressure regulator valve and their is no doubt about oil

[ptsac]

Is this pressure with chiller running? Did you change the oil filter? Is the oil getting hot? Check the oil cooler.
Oil should be no more than 45c feed temperature, please list some more info.

[goshen]

Hi what type of unit and make are we dealing with?