oil fail

[hem057]

I posted May 25 about this unit, 9RB1 0760 TFE
provided all the details on that post, unit has been running fine for months not tripping, now in the last week tripping again, oil pressure is fine, oil level good, watched it for 45 minutes yesterday ran fine, customer called and unit has to be reset three times today, went back checked oil pump pressure, there were alot of good suggestions in that post, but nothing checks out as a problem, any other suggestions

[NormChris]

If the compressor goes off on its internal overloads it may also leave the oil failure control in the circuit. If that is the case it will trip on the oil failure control simply because the compressor is not operating.

By the time you arrive the compressor has cooled and the system is out on the manual reset oil failure control leaving you with the idea that it failed on an oil related problem when that is not the problem at all.

Operate the system and look for indications of compressor overheating instead of an oil related problem.

Norm

[hem057]

I was there yesterday, just getting in the door and went over to check the defrost clock position when I heard it trip, walked over, compressor not hot, after couple of minutes reset unit and never failed again for 45 minutes

[primmers]

i know this is throwing parts at the problem, but try another switch..

[rocket]

oil thinned by overheating is the most common cause
of your problem so check your oil condition

take a look at the oil pickup screen, may be clogged

[cold don]

need more info. Are you resetting brakeror oil safty?check amps at unit and braker panel tightenall wires,maybe weak braker

[Dowadudda]

did you check the contacts on the contactor?

[dirtyboy103us]

is this a new oil control sentronic if it is clean the screen
on the sensor and check condition of o-ring they tend to get old and worn or cracked if so replace it had some compressor
that would run for days then trip off
also do fans shut down during defrost could be washing out compressor after defrost

[hem057]

thanks for the comments, changed the oil safety 2 months ago, yes this is the oil safety that is being reset not the circuit breaker, good suggestion about oil quality, would a lab test work for this quality check, and screen condition is another good question,
will check them out

[drifter43]

I agree with compressor problem or not starting as the most probable cause at this point, check contactor if 3 ph could be single phasing intermittently, this could explain what you had seen. Also check your SH at the compressor, dont forget that a floding TXV can wash the oil out of the compressor and cause oil failure this can be intermittent too, I have seen this several times. Hope this helps.

[R12rules]

Originally posted by dirtyboy103us
is this a new oil control sentronic if it is clean the screen on the sensor and check condition of o-ring they tend to get old and worn or cracked if so replace it had some compressor that would run for days then trip off .



I agree.

Maybe you could simply attach a recorder/ datalogger to the system and record your pressures. Including your oil pressure. Then see if you can find a "trend" whenever this sucker is going off.

Like; only after defrost. Or only after "X" event takes place ...

[Dowadudda]

it aint an oil problem. Your asking for the pump from the control cicuit, but she aint running, so the oil control aint seeing net oil, but it's being told to.