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akcwby
29-12-2009, 11:38 PM
I have a Copeland Discus compressor for a walk-in freezer. When the compressor start the oil bubbles bad like liquid is in the crankcase. The unit has an accumulator and there is no sweating, frost or ice on the piping. The superheat at the compressor is high but I hesitant to adjust until I know why the oil is bubbling. I appreciate any advise with this :)

monkey spanners
30-12-2009, 12:03 AM
Is the crankcase heater working?

akcwby
30-12-2009, 12:11 AM
Thank you spanners! The condensing unit is inside the building so I didnt even think to check that. I will check that first thing when I get back to work.

goshen
30-12-2009, 06:13 AM
I have a Copeland Discus compressor for a walk-in freezer. When the compressor start the oil bubbles bad like liquid is in the crankcase. The unit has an accumulator and there is no sweating, frost or ice on the piping. The superheat at the compressor is high but I hesitant to adjust until I know why the oil is bubbling. I appreciate any advise with this :)
Hi u might want to check the oil return valve if u have one it should be on a timer that opens 3-5 minutes after starting comp this valve if not set correctly could return liquid.:)

Magoo
31-12-2009, 04:38 AM
You will always get bubbling efect in sightglass from agitation, once compressor starts the oil level you see will foam up, but should settle down so-long as the CCH is keeping oil temp at /or around +40'C. The sight glass is filled by top and bottom holes from sump level, as a dampering effect, so a drop in pressure when comp starts will create bubbling, if sump over filled the crank will beat the hell out of it as well. From memory the max oil level is approx 2/3 of sight glass range.
magoo

akcwby
03-01-2010, 09:16 AM
Hello Goshen.
The unit doesn't have a oil return valve. Out of the separator straight into the suction line.

Mr. Magoo.
The foamed up sight glass starts shortly after compressor starts and stays completely foamed until compressor stops and it settles down. When everything has settled the oil is about 2/3 up the sight glass. Could you please explain , "The sight glass is filled by top and bottom holes from sump level, as a dampering effect,...." Thank you guys for your replies.