Draining oil from rotary comp.

[nike123]

I have come in possession of rotary compressor for air-conditioning unit in witch previously original compressor has blown. Service tech that changed compressor didn't do flushing of unit and tubes prior to compressor change, and now, I need to drain oil and flush compressor and everything else (oil from new compressor is already brown).:(

Is there some clever and easy way (procedure) to thoroughly drain and flush rotary compressor without un-brazing the accumulator?

Can I use Suniso 4GS oil with air-con. rotary compressors for R22?

Thanks in advance on yours kind contribution!

[monkey spanners]

In many rotary AC compressors the casing is open to the high side/discharge, this is to use the 'can' as a mufflers and oil seperator. I would think that you could tip the compressor upsidedown and tip the oil out the discharge pipe, measure how much comes out. Is the old one still about to try this with? I would think 3GS oil would be ok. I'd also fit a burn out drier.

Jon

[Pooh]

Nike123
I would go with Monkeyspanners in respect of fitting a burn out drier and new liquid line drier but would not bother with emptying the comp unless the an oil test showed very acidic oil. If you un braze the comp empty the oil out replace it and then rebraze it in without OFN you will produce more oxidisation than you already have. I would firstly do an acid test and take it from there.

Ian

[nike123]

In many rotary AC compressors the casing is open to the high side/discharge, this is to use the 'can' as a mufflers and oil seperator. I would think that you could tip the compressor upsidedown and tip the oil out the discharge pipe, measure how much comes out. Is the old one still about to try this with? I would think 3GS oil would be ok. I'd also fit a burn out drier.

Jon

Thanks for your answer.
Yes, the old compressor is still at customer possession, and I will try as you said.
What about low side and accumulator?
Regarding the oil, I found that Suniso 4G DID is recommended for Matsu****a rotary compressors for R22 (this particular compressor is Mitsubishi).

This oil is hard to find here, so is it possible to use Suniso 4GS instead?

Does anyone have details for Suniso 4G DID?

Of course that I will fit burn-out filter after I flush (and unplug) the unit, because the previous guy did not do that, and thus contaminated (and plugged) system with burned debris.

[nike123]

Nike123
I would go with Monkeyspanners in respect of fitting a burn out drier and new liquid line drier but would not bother with emptying the comp unless the an oil test showed very acidic oil. If you un braze the comp empty the oil out replace it and then rebraze it in without OFN you will produce more oxidisation than you already have. I would firstly do an acid test and take it from there.

Ian

Thank you for your contribution.
I would never leave oil colored (dark brown) and smelled lake this, in new compressor, if I have any chance to properly drain (and flush) oil. :eek:


Brazing "small" systems without OFN is not my working practice.
I think that new liquid dryer is always pair with new compressor or any major part change in refrigeration circuit.