View Full Version : Changing oil in rotary?
boshuter
11-13-2007, 11:13 AM
Ok.... how do you guys go about changing oil in a rotary compressor? :shrug:
I found out that just turning it upside down doesn't work, or at least it would take a very long time. Any suggestions?
I had same problem.
but put it upside down and be patient, everyting wil come out via the hiside, it takes ~15-20min to get it out on those rotarys I've change oil on.
cheers
Tim
august123
11-13-2007, 12:08 PM
On some (rare) Rotarys you have an extra port for Oil Change.
And not every Rotary lets out his oil when you put upside down- some have a High Port going deeper into Case and nothin will come out.
You will have to drill a small hole into body and close it after the Oil Change with a Schrader Valve...
killermiller
11-13-2007, 12:52 PM
How is the oil changed when these units are mounted somewhere?
quintus
11-13-2007, 01:02 PM
You will habe to drill a small hole into body and close it after the Oil Change with a Schrader Valve...
what??????????????????:confused:
jinu117
11-13-2007, 03:30 PM
Yeah... seen some people doing that... -_-;
I would think though proper oil charge removal tool will be able to squeeze in there :) I never tried using mine on rotary but I can't see why not.
boshuter
11-13-2007, 04:35 PM
Hmmm...... I can't believe with all the rotary systems being that more people haven't changed oil in a rotary.
Turning it upside down resulted in a few drops finally coming out of the suction side, and a few drops out of the discharge side.
I really don't want to drill a hole in it, but will if that's what it takes. I don't think I'd plug it back with a schrader valve though, probably braze it shut. What type of tool is the "proper" oil charge removal tool? If it's some kind of suction device with a tube, the only way to do it on rotary would have to be through the discharge side.
I really figured this would be an easy question for some of you guys. :)
jinu117
11-13-2007, 04:49 PM
Problem with rotary is... I never really get to deal with it much :)
I hate noise for #1. So that kills most of my build ever based on rotary.
And than the only rotary that are actively used are for in wall or window A/C which I typically don't deal with at all. (it's cheaper to replace than getting repair personnel in or spending time on it to be honest... go cheap labor from China)
Even in most residential and small commercial one, it is standard practice to change copressor once there is need to change oil unless system was clean to begin with (and these are typically piston or scroll types).
We probably have most selection of people used to playing with rotary in here than most major refrigeration related forums do... ahaha. (well I haven't found any appliance repair tradesman forum really)
Tonic
11-13-2007, 05:25 PM
If someone is worrying about debrises getting inside, then using nail would be a good idea. Drill a bit, put nail, and BANG few times with hammer and braze Schraeder valve.
stockhatch
11-15-2007, 11:33 AM
I drilled a hole in mine and drained, refilled, then weld hole shut with MIG. Worked great.
runmc
11-15-2007, 11:49 AM
I drilled a hole in a couple of them. :eek2:
boshuter
11-15-2007, 05:37 PM
I'm seriously considering the drilling idea... I think mig welding it shut would be the best way to go. It has 3 places about 2" up from the bottom that look like welded shut holes. Would it be best to drill in the bottom of the compressor, or in the side about where those other holes are/were?
teyber
11-15-2007, 05:43 PM
I drilled a hole in mine and drained, refilled, then weld hole shut with MIG. Worked great.
gas mig or wire feed mig?
teyber
11-15-2007, 05:43 PM
sorry to double post but drewgod(drewmeister) has a good thing on that:
http://forums.extremeoverclocking.com/showthread.php?t=231428
jinu117
11-15-2007, 05:50 PM
http://www.yellowjacket.com/HVACRProducts.asp?t=HVACR&l=9&c=96&p=215
Keep thinking this is better route to go than drilling... You know you will be using it in the future anyway, right Bos?
runmc
11-15-2007, 05:57 PM
I drilled in the top and brazed it back. Can't say I"m suggesting this. It was something I did on a personal basis. :shrug: :ROTF:
some compressors do have an accesspoint on the top thats marked oil onl. dunno why some doesn't.. well as far as I've exerpeince It's either the service hole or the discharge hole the oil comes out from :)
boshuter
11-15-2007, 08:09 PM
http://www.yellowjacket.com/HVACRProducts.asp?t=HVACR&l=9&c=96&p=215
Keep thinking this is better route to go than drilling... You know you will be using it in the future anyway, right Bos?
I just don't think that will work with a rotary, there is no way to access the oil through the suction or discharge side with a tool like that. Take a look at the link teyber posted, it's a very good explanation of how to change oil in a rotary. Looks like it's a lot more involved that I had anticipated, but I feel I really need to replace the oil in this one, it's POE and I'm just afraid it's been open to atmosphere. The lines were not crimped or brazed shut, just taped over, and I'd rather be safe than sorry. ;)
sorry to double post but drewgod(drewmeister) has a good thing on that:
http://forums.extremeoverclocking.com/showthread.php?t=231428
Nice find, thats the kind of info I was looking for.. :up:
runmc
11-15-2007, 08:28 PM
If you decide to put a valve in the top, hold the compressor upside down when you drill the hole. :)
jinu117
11-15-2007, 08:47 PM
And maybe 5 PSI of nitrogen at suction line :) Most likely any debris will jump right back out :P I am not sure on rotary to be quite honest with you since I never diseceted one :P The pump as thin tubing which you can push in (think it was 1/4" pvc hose or something) and suck things out. (Actually might be smaller than 1/4" since i was able to shove it through 1/4" opening).
Good luck :)
teyber
11-15-2007, 09:35 PM
Alright, i;m a noob but drilling a hole in a rotary seems quite dumb. "another very popular type of compressor is the rotary type. this has some distinct advantages as far as vibration and moving parts are concerned. The materials of construction are very similar to those of the reciprocating pump... The operation of the stationary blade type is as fllows: the shaft rotates in a chamber so the eccentric on the shaft or the enlargement of the shaft rubs constantly against the outer wall of this chamber. As the rotor turns around in this chamber, the blade imprisons quantities of gas which are compressed into a smaller space, building up pressure and temperature and finally forcing the gas into the high pressure side of the system"
So unless this chamber is not near the outside shelving, Any bad surface area will reduce the efficiency of the compressor, as gas could be able to escape the discharge? This is of course, depending if the outside shell is right outside what i said above....
mytekcontrols
11-17-2007, 08:59 AM
This is a good thread, since I was also wondering about how to do this. Although in my case it is to change the oil from AB to POE.
I was thinking about putting the hole low, as in the side of the compressor, but down as close as possible to the bottom. This would allow me to easily do oil inspections, and/or changes without having to remove the compressor from a working design, or having to turn the whole unit upside down. How much room do think I would have before I hit something when drilling in from this location?
As for preventing chips, I have seen special drill bits (I forget what they are called) that have been undercut in such a way that only the outer edge actually removes material when drilling. This ends up creating a disc of metal that is kinda like a knock-out being easily removed (also doesn't leave much of burr). I've ground my own bits to do this as well, but it does require a narrow grinding wheel with a sharp (not rounded) edge.
I also like the idea of permanently installing a shrader type access fiting.
boshuter
11-17-2007, 09:31 AM
This is a good thread, since I was also wondering about how to do this. Although in my case it is to change the oil from AB to POE.
I was thinking about putting the hole low, as in the side of the compressor, but down as close as possible to the bottom. This would allow me to easily do oil inspections, and/or changes without having to remove the compressor from a working design, or having to turn the whole unit upside down. How much room do think I would have before I hit something when drilling in from this location?
As for preventing chips, I have seen special drill bits (I forget what they are called) that have been undercut in such a way that only the outer edge actually removes material when drilling. This ends up creating a disc of metal that is kinda like a knock-out being easily removed (also doesn't leave much of burr). I've ground my own bits to do this as well, but it does require a narrow grinding wheel with a sharp (not rounded) edge.
I also like the idea of permanently installing a shrader type access fiting.
Mytek..... check out the link in post 15... the way it sounds there are 2 seperate sections in a rotary that need to be drained, top and bottom.
jinu117
11-17-2007, 11:05 AM
Good to see you Mytekcontrols :)
Have you been building any new interesting creation to show us for?
And in personal level, I would like to know if Cryotek is doing well in general as well :) Seems like S73ph3n has been out of touch with him as well and he was being exceptionally helpful at the time and being very generous about sharing valuable informations.
Glad to see you around :)
mytekcontrols
11-17-2007, 06:53 PM
Hi jinu :)
Cryotek is doing fine, he's just been extremely busy with his business, which has been growing quite a bit lately. And yes it would be great to have him back on this forum, because as you mentioned, he has much to offer.
Have you been building any new interesting creation to show us for?
Just like Nol, I've been collecting materials for my next project. It'll be at least a 3 stage autocascade, with probably around 5 refrigerants in the mix. And not to break from a theme, I am basing it on a common window AC unit. Although this time I'll try to jazz up the enclosure so it wont look like what it used to be. Should be fun, and of course I'll fully document it to share with you guys.
I have also been very busy myself (and not on the forums), but unfortunately this time has not been spent on my own projects. I have to make a living, and that means for right now, I'm working on other peoples stuff :(
teyber
11-17-2007, 11:35 PM
sounds interesting!
and about the bits: either a hole saw, but i think your talking of a forstner bit. I think i spelled it horribly wrong (loL!) but it cuts with the outside.
Reed
mytekcontrols
11-18-2007, 10:32 AM
Mytek..... check out the link in post 15... the way it sounds there are 2 seperate sections in a rotary that need to be drained, top and bottom.
Thanks boshuter! That link really has some great info, and yes it does sound like to do a complete drain of all the oil I would need more than just a bottom drain. However for taking samples, the bottom drain would still be quite good.
i think your talking of a forstner bit
Yes I am, and thanks for knowing the correct answer teyber :up:
gosmeyer
11-18-2007, 11:04 AM
forstner bit (for wood)
hole saw (wood and steel)
Just use reg. twist drill. No need to go larger than 1/2" Turn it upside down and let gravity keep chips out.
stockhatch
11-19-2007, 05:20 AM
gas mig or wire feed mig?
Gas. Though really, all MIG is wire feed. I think you meant gas or flux core. :)
Xeon th MG Pony
11-19-2007, 06:00 AM
Just a note laquer thinner as a flushing agent is bad umkay!
Use isopropyl alcohol as it wont degrade the windings!
DetroitAC
11-19-2007, 06:38 AM
Embraco believes that alcohol degrades the motor windings.
http://www.embraco.com.br/portugue/produtos/00007.pdf
:fact: page 39
mytekcontrols
11-19-2007, 09:37 AM
DetroitAC stated: Embraco believes that alcohol degrades the motor windings.
Good point :eek:
Quoted from the Embraco manual: Never use alcohol or other byproducts as a solvent. They cause corrosion on the compressor tubes and metallic parts and the electric insulation becomes brittle.
This was of particular interest to me since it has become standard practice where I work in dealing with system burn-outs. Although in our case we never re-use the existing compressor. So in other words, it would seem highly unlikely that it would apply in our circumstance. We also pull out the liquid line dryer, and oil separators after flushing and evacuation has been performed, and then replace with new. So all that is left, is the copper piping, which should not have been affected by the alcohol.
Still, I would think if the alcohol is not left to sit inside of the compressor for an extended period of time, that no serious damage would occur. Of course this means doing a good evacuation soon after the flush, in which to boil off any residual alcohol, and suck it out of the system. Be sure to put a cold trap inline with the vacuum pump, so as not to contaminate the pump oil with alcohol. An example has been provided below.
PhilippF
11-19-2007, 10:23 AM
Ha! Got ya! I knew there was an old post of somebody who converted an a/c into an autocascade to condense alcohol vapors when cleaning a system with alcohol! :)
http://www.xtremesystems.org/forums/showthread.php?t=144007
mytekcontrols
11-19-2007, 11:34 AM
Ha! Got ya! I knew there was an old post of somebody who converted an a/c into an autocascade to condense alcohol vapors when cleaning a system with alcohol!
Yes you did ;) Am I in trouble?
PhilippF
11-19-2007, 11:41 AM
Am I in trouble?
Of course you are in trouble! Now you will have to build another great autocascade! Immediately!
:welcome: back!
piotres
11-20-2007, 03:45 PM
If someone is worrying about debrises getting inside, then using nail would be a good idea. Drill a bit, put nail, and BANG few times with hammer and braze Schraeder valve.
Tonic is back ? :clap: OMG I can't believe :D .
Sorry for OT .
jinu117
11-20-2007, 06:19 PM
Tonic is back ? :clap: OMG I can't believe :D .
Sorry for OT .
Was wondering where you were gone myself.... talk to yourself man :)
[XC] gomeler
11-20-2007, 06:31 PM
http://www.yellowjacket.com/HVACRProducts.asp?t=HVACR&l=9&c=96&p=215
Keep thinking this is better route to go than drilling... You know you will be using it in the future anyway, right Bos?
Holy cow, going to United Refrigeration to try and find one of those.. would make my life so much easier :eek:
piotres
11-21-2007, 02:51 AM
Was wondering where you were gone myself.... talk to yourself man :)
Hehe, I'll post one unit today ;) . I'm still making this :D .
jinu117
11-21-2007, 02:55 AM
Gomeler... check the other one with foot pump before you buy! I am using hand one since most of time I am using for small units but I can see how bothersome it could become for actual big unit going over 2-3 hp...
Xeon th MG Pony
11-21-2007, 03:07 AM
well don't tell embraco I'm using Iso, that way they wont phone the compressor and tell it to break!
Been using it long time not a single issue, in and out and man does it get rid of the sludge!
_HL4E_HalfLife_
11-21-2007, 12:47 PM
I'm seriously considering the drilling idea... I think mig welding it shut would be the best way to go. It has 3 places about 2" up from the bottom that look like welded shut holes. Would it be best to drill in the bottom of the compressor, or in the side about where those other holes are/were?
Those 3 welds ur talking about are on all rotary's and are done at the factory where it was made. The 3 weld spots are what holds the stator firmly in place inside the shell.
Something u can try:
Alot of the time the oil won't come out of the discharge port is because when u tip the compressor upsidedown ur creating a slight vacuum inside the compressor which stops the oil from draining so to solve this all u need to do is run the compressor while its upsidedown this will suck in air and turn that slight vacuum into a positive pressure which will force the oil out the discharge. Don't worry running the compressor for 15-20 seconds upsidedown without oil isn't gonna damage it.
mytekcontrols
11-21-2007, 06:08 PM
well don't tell embraco I'm using Iso, that way they wont phone the compressor and tell it to break!
Been using it long time not a single issue, in and out and man does it get rid of the sludge!
We use it with a gasoline pump, and run a continuous flow through an entire autocascade system for up to 20 minutes. This really breaks up the yucky stuff :sick:
Alot of the time the oil won't come out of the discharge port is because when u tip the compressor upsidedown ur creating a slight vacuum inside the compressor which stops the oil from draining so to solve this all u need to do is run the compressor while its upsidedown this will suck in air and turn that slight vacuum into a positive pressure which will force the oil out the discharge.
I like this idea very much, and it makes perfect sense.