Oil Change due to comp burnout

[SkyWalker]

hi guys, doing a comp change next week on a VRV, inverter driven comp is down to earth, I haven't done an oil test but I am worried about oil in system and the other comp, if the oil has circulated around system. DOL comp is a scroll

I plan on either using acid away, anyone used this before? isit good? or pulling oil out of DOL comp (hermetic)

to pull the oil out I was thinking I might try and use an empty reclaim bottle (with Liquid and vapour connections) and use vac pump to pull it out (hose down suction pipe of comp, save completely sweating it out), if i do this is it consider ok to weigh the oil out rather than a ml measure? for replacement amount?

http://www.nucalgon.com/assets/prodlit/3-78.pdf this would do the job but seems a waste of £ if my method is safe?

how would you guys go about it?

thanks

[Brian_UK]

Which make is the unit?

Seem to remember that Daikin did an oil kit for compressor changes which included the drain pan, new oil and bits. (Could be wrong though)

[frank]

or pulling oil out of DOL comp (hermetic)

to pull the oil out I was thinking I might try and use an empty reclaim bottle (with Liquid and vapour connections) and use vac pump to pull it out (hose down suction pipe of comp, save completely sweating it out

how would you guys go about it?

I've never done or seen anyone put a hose down the suction port of a compressor and suck the oil out?

Can it be done?

Personally, I would take the compressor out and pour the oil out of the suction port.
Still not 100% guaranteed, but the remaining oil should then dilute with the new oil, which should be monitored and changed as necessary

[thebigcheese]

drill the shell and weld in a schyder

[SkyWalker]

hi guys, Brian not to sure on the model cant remember sorry, Frank I was trying to avoid having to completely remove the comp just to get oil out

bigcheese, thanks for your post but i don't like the sound of that, and the fact i don't own a welder doesn't help!

what about acid away? anyone used it? I went to buy an oil test kit from the wholesalers last year and they said many people just buy "acid away" and don't test, they buy a test kit as there similar priced, acid or no acid with "acid away" the oil will be neutralised???

and weighing oil instead of measuring in a container? if I use reclaim bottle i want to leave it there until a later date you see and i wouldn't be able to see how much was there, weighing would be my only option unless i drain it out.

[thebigcheese]

by weld i meant silver solder,

try it on an old comp its not too bad

i wouldnt do it on a good system unless i needed too ie real bad oil problems or retrofit etc

[monkey spanners]

I've never done or seen anyone put a hose down the suction port of a compressor and suck the oil out?

Can it be done?

Personally, I would take the compressor out and pour the oil out of the suction port.
Still not 100% guaranteed, but the remaining oil should then dilute with the new oil, which should be monitored and changed as necessary

Yes you can but it depends on the type of compressor, bigger the better. You need the oil to be nice and hot and to have some thin and very flexible tube. I use model car silicon fuel hose. Measure how far it is from the suction port to the bottom of the comp and use that as a guide as to how much to feed in. It takes ages as the hole in the fuel tube isn't much bigger than a pressure couple.
I use an old disposable cylinder i have brazed a 1/4" tap on, vac on the original tap. You can never be sure how much oil is left in unless the comp has a sightglass.
A little ofn will push the oil back out again so you can measure how much you have removed.

I think i would be tempted to remove the comp and tip the oil out, but it would depend on the unit, comp, etc.

I have not tried the acid away stuff.

Jon

[SkyWalker]

ok monkey thank you, i might just remove it like you say, but hey its nice to try and make life a little easier, i was thinking of using a refer line but like you say this will be too rigid.

[stufus]

I'm not a fan of acid away, i don't buy into it ! Fair enough you may neutralise the "acid" in the system . But that's no guarantee you're dealing with possible washout containments due to a burnout such as shelac debris and the like.
A lot of original manufacturers offer similar stuff ! best check with them ,no point spending big bucks on a compressor and using acid away only to find the OM doesn't agreee , and your warranty and the clients is void .
Cheers
Stu

[monkey spanners]

This is the sort of tube i have used for tricky comps.

http://cgi.ebay.co.uk/FUEL-TUBE-sili...item230da7edaa

And on this vid there is some random monkey showing the oil sucky thing in action, start viewing from 1 minute...

http://www.youtube.com/watch?v=d5N9cqk-We0

You might not want to cut your comp open though

Also you can get an idea of the things the tube can get caught on as you feed it in, this is why it needs to be super flexible.

[Gingerair]

I have used acid away before, but after oil testing a year later the acidity has returned.
There's also a max ratio of acid-away to oil that can be used so if you re-test at a later date & the acidity has returned, you may have to carry out an oil change any way..
Depends how bad the burn out is realy. It's an option & although easy, it's but by no means the best long term option.
Oil & filter/drier changes are the way to go in my opinion & preferably a new gas charge.
Also not forgetting to identify why the burn-out occured in the first place..

[Fri3Oil System]

Hi,

Acidaway neutralises acids, but, how much acid do you have in the circuits? hence, how much acidaway do you need?
Besides, acids are spread all trhough the installation, and you won't be sure you have eliminate all acid.

At the end, you have to recover all the stuff you have put, which is a diffilcult task. But, besides, there might still be some acid around,... some acidaway, and still part of the substance obtained by the reaction between acidaway and acids...

All these substances will remain in the "syphons" of the circuits, and you won't get them out just by blowing with N2.

If you then put new oil, it would get contaminated as well with the rest of acid remaining there, and your problem will remain.

Regards,

Nando.

[Gingerair]

Thanks Nando, good to see you back..

[Fri3Oil System]

Thanks Nando, good to see you back..

Cheers Gingerair,

just been watching from the shadow, I never was out.

Regards,

Nando.

[Tayters]

Don't modern AC scrolls have the shell at discharge pressure instead of the suction?

If you were to poke a tube down the suction pipe it would go into the scroll part not the bottom of the pot. Might need to check how your compressor is constructed first.

Andy.

[Emmett]

I am a little confused by this thread, I often have to read and re-read posts as I am American and frequently do not fully understand the european lingo, however am I understanding that you are changing out a compressor and want to know about acid away? If you are changing out the compressor you shouldnt need to suck or push the oil out of it, remove it install the new compressor and use manufacturer oil quantity recomendation. If I am misunderstanding this and you need to remove oil from a compressor copeland makes just what you are looking for it is a dip tube you cut to length and it comes with a valve it can be left in the compressor for future oil changes. I would not use the acid away I would install a removable core suction drier and change it as well as the oil as often as is necessary to eliminate any acid.

[Tayters]

Word Up Em,

The system has 2 compressors. One is being replaced but the question regards the oil in the other compressor.

Yer ol' mucker,
Andy.

[Emmett]

Hey thank you for explaination Tayters, I still would not!!! use acid away, I have had good sucess with the dip tube and suggest you try it, if you have acid it is imparitive that you properly clean the system, add a drier as I suggested and multiple oil changes, it can be a lot of work but you wont regret it, you will have a happy customer and will not be doing any warranty work on that unit. By the way do you know what caused the failure? I highly recommend that you investigate the system throughly when you have replaced the compressor. I am currently following up on a unit that other technicians have replaced the compressor in several times in the last 3-4 years. it seems that they just replaced the component with out ever knowing why.

[Fri3Oil System]

Hey thank you for explaination Tayters, I still would not!!! use acid away, I have had good sucess with the dip tube and suggest you try it, if you have acid it is imparitive that you properly clean the system, add a drier as I suggested and multiple oil changes, it can be a lot of work but you wont regret it, you will have a happy customer and will not be doing any warranty work on that unit. By the way do you know what caused the failure? I highly recommend that you investigate the system throughly when you have replaced the compressor. I am currently following up on a unit that other technicians have replaced the compressor in several times in the last 3-4 years. it seems that they just replaced the component with out ever knowing why.

Hi Emmet,
still using acid away, and putting filters won't remove acids 100%. Multiple oil changes means a lot of labour as you said, and you won't be sure 100% taht you did remove the acids 100%.

You can get rid of it in one operation. In the USA you might be able to get a machine from Van Steenburgh, though I never saw it working, it uses more or less the same principles of our machine, so it should do a similar job, without any consumables such as acid away or lots of oil to be changed. Don't forget how "funny" is afterwards to get rid of the acid away when you finish that job.

Regards,

Nando.