Mc Quay service procedure

[bullgear420]

I'm in the hunt for a publication by McQuay: SP-0521-C, Oil-Loss guide.

I can't get to it via their website.

I have a good size machine that is losing oil and has a major leak, and I hope I'm going to have to take it apart!

[allchlrstech]

Hope this helps,oil loss is hard to troubleshoot somtimes.If it is a older chiller
without the orfice,check the center ventline sevice valve,it should be adjusted for proper vent,(barely opened,1-4 turns opened).Also check the front end to see if it will stay (no change in amps)when put into manual load/unload.

[bullgear420]

words cannot accurately convey my thanks! I will let you know how it turns out!

[boon]

anybody have a service bulletin for als150... for getting the oil to return to oilseparator i have a discharge superheat of 0 .....replaced EXV and liquid injection solenoid factory claims i have too much oil in system and that is making the exv malfunction.......oh and i weighed the charge...willing to trade info

[ryan1088]

anybody have a service bulletin for als150... for getting the oil to return to oilseparator i have a discharge superheat of 0 .....replaced EXV and liquid injection solenoid factory claims i have too much oil in system and that is making the exv malfunction.......oh and i weighed the charge...willing to trade info

Gonna have to give more info than that for us to be able to help you. Superheat? Subcooling? Exv position? Charge? Checked transducers and all sensors?

[boon]

Discharge Superheat @ 0deg
EXV Position at 350
Suction suerheat at 7deg
checked transducers and thermistors
Factory Claims too much oil in charge
is there a service bulletin on returning oil to separator all i need is a service bulletin number

[r404a]

thanks for the info

[hvac1966]

discharge superheat of 0 and suction of 7 is that possible you will get poor seperation with a low discharge superheat, but if the suction is at seven????

[boon]

sorry suction superheat is 7 deg

[ryan1088]

Something isn't making sense. What percentage was the compressor running at when readings were taken? Oil level in the separator?

[boon]

50% load, tested with amp probe oil level disappears in about 10 min compressor IS pumping liquid i can hear it sounds like marbles that would explain the low discharge superheat reading.....Factory says too much oil in charge will affect operation of TXV........What can I do to get the oil back to oil separator

[ryan1088]

Load the compressor and it should come back. Remember suction velocity helps carry the oil back. I've heard that marbles sound and I think you may have an internal gate rotor failure. Iso the compressor, take the gas out, then check the rotors. We have lost quite a few of those compressors.

[hvac1966]

That noise could also be liqud refrrigerant, your suction superheat should be rechecked with a thermocouple, with a dicharge superheat of 0 your suction superheat is probably lower than 7, iused to here that noise alot on flooded screws with charge issues, the refrigerant would then wash out the oil !!!