McQuay centrifugal chiller

[khaled hilaly]

Hello friends

I have a problem in McQuay centrifugal chiller Model WSC 079 when starting the chiller the oil pump run and shows low net pressure , the oil migrates to the condenser and oil level drops , when adding excess oil the same phenomena is repeated and more oil is lost , please tell me the reason for this case .
so many thanks

[Brian_UK]

How far does the level drop?

How long ar you running the machine for?

[khaled hilaly]

Dear Sir :

thanks for your early reply, the level drops for about two liters for period of 30 sec at pre-lubrication then micro tech display shows vane open and the chiller shut down

[ptsac]

Please list oil temperature, oil pressure and evap pressure just for starters. what is your starting oil level? is it visible in the glass?

[henrytech]

Hi Do you have a separator with in the system?

[khaled hilaly]

Dear friends

thanks for your interest the oil temp is (47 oC) , oil net pressure = 5 bar at beginning of oil pump starting then quickly drops to 1.5 bar and oil level disappears from sight glass , before oil pump operation the oil level is normal , I added oil to the sump three times to recover the normal level but the same problem was repeated

[khaled hilaly]

Dear friend
there is no oil seperator within the system

[kleen]

look like a oil leak in vane inlet maybe a torn o ring

[Steve186]

Khaled hilaly the cause of your problem is oring or orings within the igv have failed which will cause loss of oil return to pot and oil pressure this is a common problem with all mc quay centrifugal chillers I have the oil problem bulletin + check procedure to diagnose fault send me your email address