I have a 500 ton York water cooled centrif that just won't bring back her oil to the sump when loaded at 60-70%.
She has a proper oil charge. That was verified when we replaced the shaft seal last year and swapped in R-123 and new oil.
I have replaced the eductor dryer cart and verified the eductor was not fouled.
She runs at bottom of lower sight glass and oil pump chatters. If I lock her in at 90% for 24 hours, the oil will return, but as soon as she is placed back in auto and the load drops to 60-70%, the oil fades away again.
My tower water is controlling well at 85-86 degrees. CWL is 43, CHR is 49 at 60% load.
If we lose power and chiller shuts down, it's really hard to get her back up cause of low oil pressure shutdowns.
Can you guys suggest anything that might help us prop her up thru the rest of the summer? We have no extra capacity. If I load her too high, the other chillers want to hunt and cycle.
P.S. tower fan VFD is out, so fan runs max RPM's. Bypass valve works well in controlling basin temps, tho.