dkemper
06-06-2013, 04:51 PM
I've got a freshly rebuilt Copeland 6RA compressor that appears to be moving way too much oil.
Unit is a low temp R404 freezer unit, condensing unit has almost no vertical separation from the evaporator.
The compressor had originally failed with a broken rod, the rebuild included new valves, valve plates, pistons, rings and rods along with new bearings and oil pump.
I've talked with the rebuilder, he's at a loss as to what's going on with the compressor.
Crankcase pressures remain at suction or below but the unit is not pulling oil back fast enough to keep it from loosing oil pressure and shutting down. Suction and head pressures are normal for the application. To be honest, I'd expected high crankcase pressures but that does not appear to be the case.
Oil return from the helical oil separator is warm so I've good evidence the system is trying to return the oil, but still, the compressor will empty itself of oil faster than it'll return.
Prior to the rod failure, the unit had ran flawlessly for years.
I'd hate to have to hire a crane to come back out just so I can pull the compressor and return it to the rebuilder for analysis and then reinstall with yet another crane hire. Additionally, this time of year, I really can't afford the loss of the BTU's so I'd really like to leave the thing in-place but somehow I think that's not going to happen.
Anyone have any ideas?
Thanks in advance!
Unit is a low temp R404 freezer unit, condensing unit has almost no vertical separation from the evaporator.
The compressor had originally failed with a broken rod, the rebuild included new valves, valve plates, pistons, rings and rods along with new bearings and oil pump.
I've talked with the rebuilder, he's at a loss as to what's going on with the compressor.
Crankcase pressures remain at suction or below but the unit is not pulling oil back fast enough to keep it from loosing oil pressure and shutting down. Suction and head pressures are normal for the application. To be honest, I'd expected high crankcase pressures but that does not appear to be the case.
Oil return from the helical oil separator is warm so I've good evidence the system is trying to return the oil, but still, the compressor will empty itself of oil faster than it'll return.
Prior to the rod failure, the unit had ran flawlessly for years.
I'd hate to have to hire a crane to come back out just so I can pull the compressor and return it to the rebuilder for analysis and then reinstall with yet another crane hire. Additionally, this time of year, I really can't afford the loss of the BTU's so I'd really like to leave the thing in-place but somehow I think that's not going to happen.
Anyone have any ideas?
Thanks in advance!