View Full Version : Need help with Daikin EWWD-H-GX chiller

04-09-2017, 05:11 PM
Need an advice on Daikin EWWD-H (same as McQuay PFS C) chiller. 2 compressors, one circuit.
The issue is the oil return, compressor 1 become lack of oil in the separator. I think this corresponds to running on low load (~20-25% in night time, weekend).

Both load and water flows seems to be OK. Both approaches, discharge superheat also OK.

Primarily the compressor 1 was running dry on oil. Then daikin guys came and changed oil filter on the 1 compressor (compressor 2 oil filter was changed by them previously). Then they started chiller and it worked OK. As soon as they left compressor 1 became dry again. Another oil vessel became filled higher then upper sight glass. Then I came and found these shutoff valves https://prnt.sc/ggzcct closed and opened it. (Legend http://prntscr.com/ggzhws)

The chiller become to run well for more than a week including 2 weekends.
The oil level was:

mid of bottom sight glass while running
top of the bottom glass while stopped.

But today the oil level descended below bottom sight glass again.


What is the logic of oil control: when solenoids 18 http://prntscr.com/ggzjvo corresponding to each oil tank have to be opened?

All 3 oil delivery paths seems to be OK (main supply from the oil tank, draw back from flooded evap and equalizing tube). What should I check to solve an oil issue?

Is there a possibility oil level in the vessel to be raised while corresponding compressor is stopped?

I found no setting (neither in highest level menu nor in the manual) for low delta p alarm across
the oil filter (line) so compressor can proceed running without an oil. Is there a way to set this value?

Is there some sort of ready to go monitoring software for siemens based microtech III control to log parameter trends for duration of some days?