oil vanishing trick

[devlin maguire]

Last year in Oct I fitted a new scroll comp to a air con unit however it was never fully completed as my services were required in other areas during the winter shut down, I have now started to think about getting this finished for the season starting, \but when I went to check the gauges which I left on, (they were stable at 100psi both ) as it was when I left them,I noticed that the oil had vanished either that or all the oil ran to the comp and is over the sight glass it was right on the level the last time I looked although it had vanished before any ideas why this happens, cold weather drawing everything down the lines perhaps I mean its not like some buggers nicked it is it, I would expect hot weather to have an effect on viscosity to make the oil run back but cold I thought it would all stay put
Dev Maguire

[monkey spanners]

Hi Dev,

Whats it under pressure with? OFN or refrigerant? I had a copeland semi that had been off for a few months and the sightglass had started leaking, no oil in the glass so i assumed it had all leaked out, when i started recovering the remaining charge i found that the level was in fact above the level of the sightglass due to the dissolved refrigerant in the oil!
Might be worth leaving the cch on for a day or so.

http://www.youtube.com/watch?v=8N3BaoG3Oc8

Jon :)

[Tesla]

Hi Dev
With Such as chillers the oil will migrate to the evap mainly from short cycling in the cooler months and requires a good running time of 4 hours at full load to bring it back to the comp - high velocity refrigerant flow. But in your case I suppose it depends on where the comp is compare to evap and cond, it could be diluted with refrigerant or have migrated. I recon it needs a good run at full load for a few hours then check the level.

[devlin maguire]

Cheers guys its got R22 in it but not much as I did not fully charge the system as I needed to change the contactor/overload and it took ages to arrive and then the maintenance chappie lost it so it was re-oredered again a wait and by the time it came it was winter, and the AHU is two storeys above the outside unit,
Dev

[chemi-cool]

Sounds as the compressor sump is full of liquid refrigerants well as oil.
from what you say there is no heating in the crankcase and the Scottish weather is not exactly warm.
Besides that, the AHU is way above the compressor so all liquids inside it flow down slowly.
Make sure you heat the oil well before you start the unit, I would let it run half full just to heat the compressor faster.

[devlin maguire]

Now thats something I forgot the CC heater was disconnected at some point I have reconnected it but not powered it up as it would have been on all winter,I am going to get it working tommorrow and leave it on and see if the level moves cheers Chemi Cool
Dev

[Magoo]

You must have a very patient client to wait 3 + months.

[devlin maguire]

Patient Yes but they wanted all the electrical installations tested and inspected so the A/C was put on the back burner, now its Oh fizz the A/C best phone Dev.
DM

[james10]

cheers guys its got r22 in it but not much as i did not fully charge the system as i needed to change the contactor/overload and it took ages to arrive and then the maintenance chappie lost it so it was re-oredered again a wait and by the time it came it was winter, and the ahu is two storeys above the outside unit,
dev
c&g 2079?
Citb j11

[littleyapper]

was thinking the exact same thing James............mmmmm
time to start selling them new equip any hoooo thats off topic.... its defo refrigerant in the oil...

[devlin maguire]

Well after I connected the CC heater the oil returned to the correct level, but as I have said in my other post this scoll comp is very noisey, rotation is correct, discharge gets hot suction cold gauges respond and it takes gas ok, but it makes a hellavu racket any ideas ?
Dev

[monkey spanners]

They can sound noisey if they are really undercharged or running with too low a suction pressure, but i can't hear it from here!

I did have one suck in a bit of a schreader core and sound noisey for an hour or so, then quitened down and ran ok. Less said about how the core got in there the better....

[devlin maguire]

Yeah I think I will keep charging it till it shuts up or blows up any it wont beat me thats for sure
DM

[chemi-cool]

Take it easy on the charging, as MS said, sometimes it takes time for them to get quite.

[devlin maguire]

cheers folks I am back at it Mon AM so lets hope it works out
DM

[james10]

Yeah I think I will keep charging it till it shuts up or blows up any it wont beat me thats for sure
DM
How about doing the job correctly speak to the manufacturer and get the right charge weight for the unit, or you could "blow it up" and make the industry look even worse there's enough plumbers and sparkies giving us a bad name as it is

[devlin maguire]

Point taken, But I was speaking in jest, as to the charge weight it's 44 Kilo according to the people who designed built and commissioned it although I have know idea how they came up with that figure I asked for the original spec he was working from and the response was " well it's a estimate really" with that kind of proffesional attitude I think I'll go with a little at a time till I get the SC & SH where I want them.
DM