Hygroscopic POE oil

[kay86]

Sorry for opening another thread, hopefully you won't hate me but I still have plenty to learn in this journey.
Unfortunately I misplaced a cap on my compressor (1/3 HP R290 freezer compressor) and realized some days after as the inlet was completely open. I'm afraid that the POE oil mighy have been contaminated now, so I was wondering what I should do. I've tried pulling a vacuum to 800 micron, and it didnt seem to be rising a lot after that, but I've read that POE oil is very difficult to remove humidity out of, so a vacuum might not be enough. Should I swap it for new oil? Also, I realized I have a normal nitrogen tank, not a "dry nitrogen" one. Should I be afraid to reintroduce the same problem once I'll pressure test the system?
Thank you!

[kay86]

Oh, thinking about it, if I added a sight glass, would it show as "wet" if the oil was still contaminated after the final vacuum?

[RANGER1]

kay86,
If open to atmosphere, no good.
Change oil with new oil that has never been opened.
Change filter drier, if not already.
Check with your supplier about the nitrogen quality.

[kay86]

Thank you!

[kay86]

Hey, little follow up question. I've emptied out the compressor but I've only managed to recover 130ml, while the specifications say 180ml. I also flushed with nitrogen to make sure most of it would come out. Should I put back 130ml or the whole 180ml now?
Compressor was never installed so it's impossible it got lost somewhere in the system. Thank you

[seanf]

Hi kay86,

It might take a bit longer to get a good reply from the other forum members, theres a lot of posts by spam bots clogging up the "Whats New?" page. Which I think is the page most forum members check for new posts.

For me, I would probably put in what I took out. So the 130ml. And then once the system is running, keep an eye on comp temps and noise. 50ml difference seems relatively large amount to go missing?

Cheers

[kay86]

Thank you Sean, I will keep monitored both amperage and themperature of the compressor.

[Orsus_KR]

Hi Kay86:
I worked for a compressor mfr. before. We can't get entire oil out of a compressor. Reason is the compressor is run tested by the mfr. for few seconds before packing. It spreads the lub oil over mechanical parts: cylinder, muffler etc. The lubrication oil is churned at high speed (2 pole speed). This creates oil mist within compressor coating entire internal shell and also the motor windings. This qty of oil which wetted the internal surfaces and motor windings won't come out. The % may look large in small capacity compressors. That is normal. The % will be small in larger compressor having 2 or 3 lit oil.
When in doubt about nitrogen moisture content for leak test, using a drier in the nitrogen charging line could be tried. I do that "when in doubt".