Why the oil can pump out of the refrigeration compressor

[@LeifOfWilsonCreek]

Your videos are incredibly clear and informative. Thanks!

[@melvin292]

Very nice explanation on the subject. You always do a great job and make a fine video.

[@saumyadipmukherjee3115]

Hi...great video...just wanted to know that I have worked on a system where I have a bitzer compressor & oil separator at the discharge...I am facing low oil pressure & oil DP problem...the load to the refrigeration unit is also low..so I had to stabilize the superheat & subcooling with a low refrigerant charge ...... the compressors are running at minimum load always. side glass also shows bubbling at minimum load...what could be the issue? is the oil pressure dropping because of low refrigerant load & inefficiencies of oil separation by the separator at discharge? thanks

[@sbitschy]

I am here because of discussion with a colleague that claimed you don't need to worry about oil return in commercial refrigeration as much if you are using a pumpdown system because it pulls all the oil back to the compressor ... and I couldn't see how reducing the pressure and velocity of the gas would help return oil. Your video shows exactly how I pictured oil return in my head. Can anyone think of another explanation on how pumpdowns could help with oil return? I dont see how it could.

[@taylortrott7716]

I wish I had a Dad like you

[@daimlerblanco3752]

If I live close to a wise man like he is I would work for free for him just to get his knowledge

[@bradhvac5866]

Gfm thank you for all your help. I think your right we got air in the system. I was looking at our oil pump and the dumb thing is sucking air. I couldn't hear it with the chiller running. Thank you so much you have been a big help. This thing was driving me crazy lol. My coworker used the same pump originally when he made a repair on the oil line. So that's must be what happened to the r22 also. Thanks again. I'm going to try and get a video with my phone today. I will try and send it to you. It would be a good subject to teach about.

[@grayfurnaceman]

Looking forward to it. GFM

[@hg2.]

@@grayfurnaceman Did Brad HVAC send you a video? And, if yes, can you post a link to it here?

[@5400bowen]

Very nice! So I’m changing everything but the refrigerant lines, sensors, and wiring on my car AC. There was considerable (2-4 ounces with leak detection dye and gritty sealant residue) oil in the evap. Do you think I should only put a dab of new oil on all the new seals, and maybe a touch on the TXV? I have been wondering about the auto AC videos saying measure the oil in each component and replace it in that component. In the evap? In the condenser, receiver/dryer, and lines? Should I put all the oil for the system in the compressor. You have clarified that replacing oil component by component is incorrect. Any advice would be appreciated.

[@hg2.]

Great video - judging by the comments, this one sounds like an area that needed more discussion and investigation. One thing - sounds like the "oil filler cap" (would that it were that simple)... sounds like the oil filler cap should have a sign on it that says "do not add oil unless system is properly charged with refrigerant."

[@edlauren9434]

Thank you for this video. I've leaned some new and helpful information.

[@aks8264]

Hi is it advisable to use a fridge compressor as a vacuum pump? What vacuum presuure in psi will be suitable before recharging?

[@grayfurnaceman]

No. The compressor is not capable of deep enough vacuum and, because it is hermetic, it will not cool. You need 500 microns of vacuum. GFM

[@JCVET18]

Does the condensate coil need to be replaced if the LG compressor inner seal fails?

[@bradhvac5866]

I have worked on Lieberts and all kinds of different equipment. Only been working on chillers this year. I thought I understood the refrigeration cycle pretty good. But I have never seen anything like these problems before.

[@hg2.]

"Forewarned is forearmed." That's what's great about videos like this - "experience".

[@PTF491]

Hey thanks for your help have a large 2 stage 70 ton seasons 4 unit working on issues with oil pressure safety.. going to be checking the superheat closely now since watching your video. Unit has an adjustable txv on each 35 ton semi hermetic compressor circuit. I have amped out my crankcase heaters. Is there anything else I could check regarding low oil pressure loss of oil level in the sight glass?

[@grayfurnaceman]

When checking the TXV superheat, note that if one is leaking by, adjustments will make no difference. I had one unit with 20 TXVs and just one that was leaking by shut it down on low oil pressure. Also, pump pressure should be checked. GFM

[@PTF491]

grayfurnaceman just one txv was running 22 degrees lowered it to fifteen hopefully it helps.

[@PTF491]

Each ckt has one large txv two total on unit

[@PTF491]

What do you mean by leaking by?

[@hg2.]

"... amped out my crankcase heaters..." What does that mean?

[@bradhvac5866]

Awesome video. You will all so have low oil return if you have low load conditions. Gfm am I right about that? I change the poe oil in that chiller today. Set the txv back to 10 degrees superheat per manual. But I'm curios will that superheat be the same with the mo99? Also circuit 1 seems to be returning oil ok. But circuit 2 is not. Also circuit 2 is set to 16 degrees subcooling per manual but it's flashing at the site glass. I don't get it. I weighed the charge in 90% like the said. Let run about 4 cycles set the subcooling and its flashing really bad. It has a brand new txv sightglass and solenoid valve and all coils were just cleaned and all fans work. It was about 76 outside today. 65 degree water returning to evaporator. Thank you for all your help.

[@fieldpiecemike7057]

U said set subcooling. Is that a typo

[@bradhvac5866]

No added enough refrigerant to set the subcooling. The manual said they wanted 16 degrees of subcooling. I had only charge it to 90% of total charge. Then added the rest by measuring the subcooling until I had 16 degrees.

[@grayfurnaceman]

Low load conditions could also cause that. The superheat is generally the same with MO99. Do you have a temp difference in the liquid line upstream of the sight glass? GFM

[@capitolrefrigerationheatin7501]

i thought your sight glass would flash if you have a big heat load,because the refrigerant is evaporating very fast??? why would sight glass flash with low load and 16 degree subcooling, possible restriction????

[@grayfurnaceman]

Once the system is running and settled down, there should be no bubbles in the sight glass, even under high load. If you have bubbles, that indicates a restriction upstream of the sight glass or possibly air in the system. GFM

[@Spector_NS5_RD]

thanks. a lot of times when i'm changing out a system, when i go to cut the line set from the evap, compressor oil pours out everywhere. this is with systems that have the condenser higher than the evap.

[@grayfurnaceman]

You would also need to know the reason for the replacement. Locked rotor from low charge would cause that. GFM

[@jeffrystout6222]

@@grayfurnaceman Another thing to consider: Is there a trap at the outlet of the evaperator? If evap is lower than the condenser a trap is warranted.

[@nickmiller4544]

What do you think of installing oil separator on discharge line, I never see anybody doing it as additional recommendation, I saw oil separator only from factory design.

[@grayfurnaceman]

Oil separators are used in systems that have oil return problems mostly ammonia machines because ammonia does not mix with oil. However, no oil separator is 100%, so if there is an oil return problem on a system, the problem will still exist, it just will take longer to show itself. GFM

[@davidu.udofia961]

Great video . Sir can oil be added to a rotary type compressor? it think the oil chamber in rotary compressors are sealed ?. i assume pumping of oil into the system with rotary compressors signifies the seal of the oil chamber is bad which will reduce the efficiency of the system .

[@grayfurnaceman]

If you mean scroll compressors, there is no separation of oil from the system. The oil circulates with the refrigerant. GFM

[@daniellikhomo8102]

Very good answer

[@charlesajouri7233]

Excellent. Learned something new.

[@terryj.macmullen9968]

refrigeration compressors are designed to pump oil to lubricate the valves and seats to make them more efficient.they also rely on refrigerant ,which mixes with oil,to return oil to the compressor.

[@grayfurnaceman]

What is your point? Not trying to beat you up. GFM

[@ayesharahmathkhan4981]

very nice explanation great sir

[@grayfurnaceman]

Thanks for the support. GFM

[@Guyhakverdi]

When we have vertical lift 40'-50' can we use just solenoid instead of traps? Or do both ? When manufacturer says maximum lift... Does it mean without traps?

[@grayfurnaceman]

I am not sure how a solenoid would help with oil return. Install instructions say maximum lift, they mean without traps. GFM

[@fieldpiecemike7057]

Great info video. You freakin kick ass.

[@grayfurnaceman]

Thanks for the support. GFM

[@stevengasssr3010]

Awesome video.

[@zoidelux]

Thanks! Can you do a video on how to add oil to a compressor?

[@alluwant2049]

you got an answer

[@randallcalhoun6604]

good vid. any info on oil loss via a leaky system. schrader ports that have evidence of oil loss etc? is there a way to tell if a compressor is low on oil without sightglass like residential systems? thanks for your vids and info contained in them.

[@grayfurnaceman]

Oil slicks on service valves, Schrader, etc do not indicate an appreciable oil loss. No, there is no way to know if there is a low level without a sightglass unless there is a low oil pressure cutout. GFM

[@throttlebottle5906]

very good subject to cover :)

[@josephkouter-pq5sr]

What is the problem if a compressor run smooth for a long time after the first run it's run short and makes a puff sound on the compressor

[@-slemantech6136]

Thank you

[@ccthepope]

thanks for posting!

[@grayfurnaceman]

Welcome GFM

[@miamiwax5504]

I have black stuff leaking underneath my fridge but it doesn't smell like oil or feel oily

[@tptm100]

I like the look, I recognize the voice though

[@jhuh1758]

great HVAC Guru

[@xaviermaquilon9832]

i have a mini refrigerator compressor overheating and not cooling how can i fix it

[@grayfurnaceman]

Its dead. Replace it. GFM

[@geojor]

good stuff, thank you ...

[@heavydiesel]

Wise words!

[@aissatouthiam2375]

The oil of bizer compressor is not return quickly until the compressor off I need help ????

[@grayfurnaceman]

There could be several problems. Low charge, incorrect TXV setting, piping too long or too large are a few. GFM

[@hg2.]

Wow... This is an HVAC nuance if there ever was one. It's scary to think how this lesson was learned. In a different video (from a knowledgeable tech, but lacking in teaching skills) there just a hint/whiff about this in a discussion about accumulators. Now I can go back and fill in some of the blanks. Thank you for making.

[@grayfurnaceman]

Welcome GFM

[@DWAYNE2ism]

Hey good day sir

[@DWAYNE2ism]

Had a compressor on a package unit. I took the amperage on the compressor which is three phase. And didn't get any reading on the lines.

[@5400bowen]

PS: those 6 thumbs down have got to be trolls.

[@shanedittmer4344]

If oil is leaking out of compressor. I must have a hole in my line...right?

[@grayfurnaceman]

This is not that simple. How do you know you are low on oil? GFM

[@shanedittmer4344]

@@grayfurnaceman On the margarita machine. I found oil underneath it. So i checked underneath the compressor and seen oil.

[@shanedittmer4344]

As far as being low on oil... I have no idea on checking that out.

[@grayfurnaceman]

@@shanedittmer4344 The repair depends on where the leak is coming from. If it is from the compressor itself, the only sensible repair is replacement of the compressor. If it is from one of the lines, it can be repaired. In either case, it is also losing and probably has lost its charge. GFM

[@grayfurnaceman]

@@shanedittmer4344 There is no effective way to check oil levels on units without an oil sight glass. If you know the oil charge of the unit, you could remove the compressor and dump out the oil, measure what came out and replace with the proper charge. GFM

[@1kreature]

Wonderful explanation! You think that may be what has happened to this refrigerator? kzbin.info/www/bejne/bZ3cqpqVprejisk Since it has a coaxial feed/return to the evaporator it feeds it on top and zigzags all the way to bottom before looping back up. I suspect the bottom of that evaporator has a lot of oil in it and the compressor is running dry causing it to pull too much amps.

[@jewdali1]

Thank you