I wrote about this unit before but I can't find the thread now. 3HP Russell. Original problem - off on oil failure. At the time I found and repaired some other items; bad box stat, bad evap fan motor, stuff like that. Comp. sight glass 1/2. Net oil press 50 lbs. Etc.
Two weeks later - off again. Oil failure. Plenty of oil, CCH works, SSH vaguely erattic, but doesn't flood back. And there's always oil in the crankcase so it's not washing out. I replaced the oil pressure control.
System ran for a few months. Until today. Same everything: 1/2 glass of oil, CCH OK, no flood-back, reset control and it runs nice.
For some reason I thought it was R-22. The Russell tag itself says R-404. I also noticed today that it has an R-502 TXV. Maybe I found "R-22" hand written on it somewhere the first time I was down there. I can't remember. Maybe I'm just a confused idiot.
I think 404 would tend to run slightly higher pressures than 502 - which would tend to starve the evap, not flood it. Right?
Head press - 210
Suc press - 22
Gross oil - 74
Amb. - 63
Liquid temp - 86.2
Suc temp 16
Someone on here mentioned some thing about the way the oil pressure control was wired. Something about it maybe got power while the compressor didn't.
I forget just how that idea went. <g>
I understand the concept - I just can't see how that could be. But at this point I'd be willing to entertain even the wildest theories. <g>