Oil Change

[MIN_Roadkill]

Ok I found two free 15,000btu Fedders air conditioners and ripped them apart. They both have rotorex rotarys compressors and I cannot get the oil out. I read that Berkut and Runmc had the same problems with their compressors and drilled holes in the top. What is the best procedure for this? Should I drill it in the top and install a shrader valve or just cut the accumulator off and install a new one?

[The Weedman]

Imo i would go with cutting off the accumulator if you have another one cause i wouldnt want to take the risk of getting any drill shavings lodged in the compressor anywhere. If your careful i guess you could go either way.
Btw how in the world did you find 2 free 15000btu compressors? lucky ******* :D

[MIN_Roadkill]

I had to go fix the computer system at one of our stores yesterday, which is a pretty big building that had alot of stuff left over from the previous owners. Anyhow while waiting on the the operating system to install, I just asked the guys if they had any old air conditioners laying around and they said there were two in the shed that came out of their houses after installing heat pumps. I was just tryin to strike up conversation and couldn't believe it when I walked out back and found those. I have been looking in local ad papers and ebay for a few months for 1 hp 115v compressors. This is also the same place that I got my case from, a 1980's IBM server.

[wdrzal]

it should drain out the process tube.

[MIN_Roadkill]

I can't even get a drop out, so I read on here to find the correct method only to find out that alot of guys couldn't get their rotary compressors to drain.

[wdrzal]

I never has a scroll compressor fail , so I can't imagine why.

[_HL4E_HalfLife_]

A scroll compressor in a window AC?????? are you sure its not a rotary? :confused:

Why would you want to drain the oil from them anyways? im assuming they still have there charge and if they do you don't need to change the oil.

[MIN_Roadkill]

Sorry half, the brain is a little slow tonight, scrolls and hermatics and rotarys oh my! I was reading compressor diagrams to make sure that i could drill a hole in the top and I think the last diagram I looked at was a scroll design.

[MIN_Roadkill]

I edited it out to avoid confusing others. Is that confusing? :confused:
I am using r404 and they came with r22. I know I can add a little propane to the mix to carry the mineral, but I would rather have new poe since the compressor is fairly old.

[berkut]

Drill a hole on the top untill your just about to penetrate and stup. You should leave only a very thin wall wich you should later pierce with a nail for example. This way no metal shavings will contaminate the compressor

[chilly1]

I never has a scroll compressor fail , so I can't imagine why.
I have seen quite a few burn up when they are set up with 35 deg F superheat. And we had every unit installed with the millenium scroll from copeland in 1998 in one tract of 300 homes fail within the 5 year warrentee .. the welds on teh motor broke the side of teh shell and it leaked.'

I Think he was talking about a rotary... These burn up quite fast with too high a superheat

[_HL4E_HalfLife_]

Another way to prevent metal shavings from getting in the compressor is to dip the drillbit in oil every 10 sec of drilling or so. Personaly i wouldn't bother replacing the oil in it bro its probily not worth the trouble.

Just use a 50/50 mixture of 404 and 290 that should be enough for good oil return.

[_HL4E_HalfLife_]

Sorry half, the brain is a little slow tonight, scrolls and hermatics and rotarys oh my! I was reading compressor diagrams to make sure that i could drill a hole in the top and I think the last diagram I looked at was a scroll design.

So are you saying the compressors arn't scrolls but rotarys instead?

OOPS I just read ur opening post at the top i guess that answers my question :p:.

Ok i think the reason no oil is coming out is because there no way for anything else to get in. By trying to drain the oil ur also trying to create a vacuum inside the compressor shell. I suggest that if you can tip the compressor upside down and turn it on for a few sec to see if any oil comes out the discharge if it does than just turn the compressor back on every few min till its empty.

[MIN_Roadkill]

I tried running the compressor and still got nothing at all out. I took my time and drilled a hole in the top with the compressor upside down so the shavings wouldn't fall inside. I believe any shavings that would make their way into the compressor would be collected in the oil waiting to drain. The hole turned out perfect and I will take it to work tommorow to mig up a pipe fitting.
The downside to this is that I still only got around 2 ounces(60cc) to drain. I ran it for a few seconds and still got no more oil out. i left it upside down for around ten minutes and nothing more came out. What oil did come out was filthy with black particles in it. I believe that a 1hp rotary holds quite a bit more than 60cc of oil but I can find no specifications for my rotorex. I know that it is common practice to only put in the same amount of oil that is taken out so I have quite a dilema here. The air conditioner had 3/8 liquid line and 1/2 suction, is it possible that the majority of the oil found its way to either the condensor or evaporator? The air conditioner had been setting upside down for who knows how long, but it did work when I tested it. Any idea how much oil I should put back in or should I just put the same amount back? It is a Rotorex C141A001.

[_HL4E_HalfLife_]

I tried running the compressor and still got nothing at all out. I took my time and drilled a hole in the top with the compressor upside down so the shavings wouldn't fall inside. I believe any shavings that would make their way into the compressor would be collected in the oil waiting to drain. The hole turned out perfect and I will take it to work tommorow to mig up a pipe fitting.
The downside to this is that I still only got around 2 ounces(60cc) to drain. I ran it for a few seconds and still got no more oil out. i left it upside down for around ten minutes and nothing more came out. What oil did come out was filthy with black particles in it. I believe that a 1hp rotary holds quite a bit more than 60cc of oil but I can find no specifications for my rotorex. I know that it is common practice to only put in the same amount of oil that is taken out so I have quite a dilema here. The air conditioner had 3/8 liquid line and 1/2 suction, is it possible that the majority of the oil found its way to either the condensor or evaporator? The air conditioner had been setting upside down for who knows how long, but it did work when I tested it. Any idea how much oil I should put back in or should I just put the same amount back? It is a Rotorex C141A001.

With the oil that came out of that was what u say than i wouldn't trust that compressor for long term use. The bearings have most likely been damaged because of long term use.

Does the oil have a strong smell to it? If it does than its probily acidic from the compressor overheating (DO NOT LET ACIDIC OIL TOUCH UR SKIN)

If i were you i would put at least 100 to 150cc of oil new oil in it even if this is more than what was originally put in it the extra oil won't hurt it. If anything it might keep it going a few months or maybe years longer. :)

[MIN_Roadkill]

I couldn't find any specification sheet for this rotorex so I had to guestimate. 1hp matzu's call for 490cc and I read that Berkut had one that held 300cc and Runmc had one that held 290cc. I finally decided on 12oz (354cc/ml). I brazed a shrader onto the high side so I could pressure check my weld for leaks then put in the oil and fired it up. I let it run to 300psi and the weld had no problems whatsoever. It took around 30 seconds to reach 300psi and sounded alot better with the new oil. I then drained the oil and it was still kinda dark, so I filled it up again then ran for a minute and drained again. I ended up doing 3 oil changes on it and now have it draining overnight since I wasn't ready to seal the unit up yet. Tommorow I will have the time to put everything back together and then I can fill it up and seal it off and begin the vacuum. That brings up another question. How long can poe set in a can that the seal has been broken on? I hope it can last overnight as I have no choice now lol. I think I should go ahead and change the oil out in the other compressor also since I bought a gallon. It was either $20 per quart or $48 per gallon so I went that route since I was uncertain of the amount needed. By the way, the poe I purchased is iso32.

[_HL4E_HalfLife_]

Yea get as much of that black crap out of the compressor as possibile.

My guess is its burnt oil because burnt oil turns dark brown to black and will become lumpy and won't flow anymore like normal oil does, that also maybe be why not much oil came out in the first place.

[s7e9h3n]

Sorry half, the brain is a little slow tonight, scrolls and hermatics and rotarys oh my! I was reading compressor diagrams to make sure that i could drill a hole in the top and I think the last diagram I looked at was a scroll design.
Although I don't know too much about these, I do know that with a brand named "Rotorex" - I'd most likely rule out the diagram of a scroll comressor :p:

[MIN_Roadkill]

I'm not real swift sometimes ;)