Changing the oil on a Hermetic A/C Compressor!

[lzenglish]

Anyone ever done it, or know how to do it? I have done it many times, as part of an A/C Compressor R&R! What would be your guesses, just for the fun of it? And cutting the compressor open at the weld is not the answer I'm looking for!

Wayne

 

[pop pop]

Not necessary. Sealed units won't contaminate the oil.

 

[lzenglish]

Not necessary. Sealed units won't contaminate the oil.

It Is necessary in some cases, as hermetic systems can be contaminated very easy! But, this is something I did for the 10 years or so, when I worked on field units for the department of defense, when Christ was a child, (or way back in the 60's), or there abouts. So your answer is you do not know?, correct?!

Wayne

 

[brewchief]

I've done it a few times and don't care if I ever do it again, we had a unit that burned a compressor up real bad that took more clean up then a new rooftop would have cost.

 

[lzenglish]

I've done it a few times and don't care if I ever do it again, we had a unit that burned a compressor up real bad that took more clean up then a new rooftop would have cost.

How did you do it, if you don't mind me asking?

Wayne

 

[brewchief]

How did you do it, if you don't mind me asking?

Wayne

Well I started by ******* what seem like three metric tons of tools and equipment up a 28' ladder and then across a roof then up another ladder to the roof the unit was on, equipment includes torches, recovery machine, tank for recovery machine, vacuum pump, nitrogen tank and regulator, about 75# of hand tools and more.

First step is to recover refrigerant, then cut out compressor, tip compressor over draining oil into a measuring bucket so we can put the same amount of oil back in. Blow nitrogen though system to push any more oil out that we can, on this unit we also ran a can of R-11 flush though it to get all we could. Set the compressor back in place and add the same amount of oil that came out, replace liquid line dryer(we removed prior to R-11 flush)with new one that is as large as we can get, add suction line filter dryer as well, both would normally be a high acid removal type, pressure test with nitrogen, vacuum down to about 2500-3000 microns and then purge with nitro again then vacuum down below 500 microns and recharge with new refrigerant.
Come back in a day or two and check pressure drop across suction line dryer and replace as needed until system is clean.

Not the hardest job but a lot of work none the less.

 

[lzenglish]

OK,brewchief, I did not see your post, before I finished mine, so this is mine,before yours, which I can relate too!!, So I will tell you how I do it! Of course, (when it is on the bench) !!!You need to cut the compresor out of the system first, and detach all the mounting bolts, and mounts. I capp the suction and discharrge lines off with rubber plugs. Turn the compessor on its side, and drill an 1/8th inch hole in the bottom center of the pot. Then set the compressor on a coffee can, and remove the rubber plugs, and let the oil flow. Then install a 5/16 inch screw, and silver solder it in place. Your story is MUCH Better than Mine!!!!

Just sharing,

Wayne