Mcquay cenrtifugal chiller WSC - 079

[khaled hilaly]

Hello friends

I have a problem on operating McQuay centrifugal chiller Model WSC-079 (350 TR) , when swithing on the chiller the oil pump start running after short time , but the chiller dosent start , and the Microtech display shows ( vane open) , the oil pump pressure is O.K , if anybody know solution for this problem please help me.

So many thanks

My E-mail : kaled572003@yahoo.com

[ptsac]

Hi Khaled,
check vc switch, check unload solenoid and relevant output relay. VC switch requires a differential pressure of approx 3.5 bar to prove that the vanes are closed. the vanes need to be closed to prevent an overload current on start up.
Also check that the service valve on top of the oil pot is not fully back seated as the 1/4" line is the drain line from the IGV.

[khaled hilaly]

so many thanks