oil return system troubleshooting

[racknovice]

A few days ago, we noticed that the oil retun line running out of the oil separator was most of the time cool. We opened up the separator and found sludge and some debris blocking off the float valve. It was serviced and the system put back in service.
Now I have noticed the opposite: the oil return line is most of the time, if not always, really hot. Is this normal?

[Brian_UK]

Sounds as though the float is now stuck open however check your crankcase temperatures and sightglasses, if fitted, for excess frothing.

[Mark]

Try installing a sight glass in the oil line, to try and determine how much oil/gas there is flowing in the line- or use the search section of the forum we have had a few threads on oil separator problems:)

[Dave Sewell]

A few days ago, we noticed that the oil retun line running out of the oil separator was most of the time cool. We opened up the separator and found sludge and some debris blocking off the float valve. It was serviced and the system put back in service.
Now I have noticed the opposite: the oil return line is most of the time, if not always, really hot. Is this normal?

Firstly have you a solenoid valve in the oil return line? If not then fit one as well as a filter and sight glass straigt away!
If as sounds certain the float to the separator is jammed open, then during the cool Panahamiam evenings, condensed refrigerant will return to the crank of the compressor with the consequent loss of the compressor.
As the oil sep. is obviously a flange type then the system is of a reasonable standard of design and therefore relates itself to a decent standard of upgrade, if not already fitted.

p.s.check the crankcase heater.

Biggest cause of mechanical compressor failure.
1) short cycling (no off cycle timer)
2) hydraulicing (too much oil or liqid refrigerant)
3) a lack of understanding of the basic fundamentals

You obviously understand the latter. To benefit yourself and your customer, advise them that a simple upgrade will both enhance their equipment and benefit you in fault diagnisis leading yo shorter downtime.

DAVE SEWELL

[EvTech]

A few days ago, we noticed that the oil retun line running out of the oil separator was most of the time cool. We opened up the separator and found sludge and some debris blocking off the float valve. It was serviced and the system put back in service.
Now I have noticed the opposite: the oil return line is most of the time, if not always, really hot. Is this normal?More than likely, as already mentioned, the float is now stuck open, and your next step would be to replace the float assembly.

[750 Valve]

Do you have oil filters fitted? We use Sporlan ROF filters - replacable type, they work well, we don't see anything in the oil thats not meant to be there.

Stick a filter between the sep and the NEW FLOAT you install

[dirtyboy103us]

oil system trouble shooting is a little complicated at times and could take some time depending on set up and controls

with that said do you have a history with this rack and as you found the float clogged ,could someone have added excessive amounts of oil and now its circulating in the system are the sight glasses full on the pumps, and whole host of other things and last thing do you have a pumper on the rack.

there are a lot of minor issue's that create mis-diagnostics's of an oil system so time and experience is needed, so take your time and gain some experience don't fix the symptom find the problem.

sludge in separator higher discharge temps causing oil breakdown or poor maintenance practice's look at the whole problem to find the cure

[coolhibby1875]

hi it sounds like someone has been charging the system with oil rather than cleaning the float i would quote the customer to fit a temprite oil system that will pull all the oil back that may be right through the system mainly the evaporators once you have pulled all the oil back you will be able to forget about the oil system as these are the best seperator/resivior on the market

[iceman381]

First I would solve the sludge problem (excessive heat on the discharge,moisture, too much oil) next I would check the float for proper operation before I installed it if any dought replace it.Replace required oil in seperator and run it. I would also install a inline sight glass.Line should be hot with oil just bubbling thru.