Server Room Down!!

[_knight_]

I'm having an issue with a Fujitsu ductless split system. New customer, no cooling. Found the complete charge had leaked out of one of the flared connections at the condenser, upon further checking found the compressor to be bad, due to a mechanical lock-up.
Ordered a new compressor, installed compressor, evacuated system down to 500 microns, and began charging. I immediately realized I had a restriction, and narrowed it down to the drier/strainer capillary tube assembly. So before getting a new assembly I wanted to try and blow it out first, during recovery I had an issue a couple of times with my charging hoses clogging, I would take my hose off and I had a "creamy" paint like residue, which seemed to be a refrigerant oil mixture. Once the refrigerant evaporated it became clear oil, not alot but just enough it was clogging the orifices on my hoses.
So I called another, "more senior" technician who said that it was normal with some types of oil and that he'd seen it before, that there was no issue there. So I blew out the strainer and capillary tube and after putting back in realized that it was again completely blocked. So I ordered a new assembly and have it on order as we speak, but I can't help but scratch that nagging feeling that the issue with the refrigerant/oil that I had in my lines might also have had something to do with it. If someone else has ran into this and has a remedy, or if I'm merely overhthinking a simple restriction, please tell me....thanks.

*Oh and when I later was putting away my vacuum pump I noticed the oil in my pump was also a creamy clear white, which was just changed before doing that evacuation.

[whec720]

Sounds like you may have a fair amount of moisture in your system which could explain your compressor failure. I'm interested, how long did the system hold at 500 micron after you shut the vacuum pump off?

[DeltaT]

Few month ago I had the exact same problem for an industrial cleaning room. Same symptoms. Ends up the refrigerant lines were 75 plus feet long, the install contractor did no purging - oops, can't do that anymore, I mean preparing the refrigerant lines with nitrogen or vacuum, and a bunch of other stuff.

Owner got the original installers back who actually stuck to their warrant and word and redid the job properly with me overlooking their backs.

The compressor pumped out the oil then mechanically froze up since the lines were too long for the oil to get back PLUS just about everything was moisture contimanited from an improper install.

How long are the lines? And remember, you can't install LL driers in what looks like the liquid line.

[hands]

If the unit doesn’t have a functional low pressure switch, I would say that the unit lost the charge through the leak at the flare fitting. Then would run in a vacuum which pulled in moisture through the cracked flare fitting and locked up the compressor. Sounds like there is a lot of moisture in the system that is causing the white foamy oil. You need to install a filter-drier and triple evacuate the system changing the vacuum pump oil often. If the cap tube gets clogged with oil, you can try heating it up with a torch or lighter, moving the flame along the cap tube to draw the oil out of it, but don't get it too hot.

[_knight_]

I believe all three of you are right. whec, I'm guessing my micron gage is not functioning properly, or is giving me false readings because I believe there to be alot of moisture in the system. DeltaT I have the same situation, my run is about 65 feet long, and hands there is not a low suction pressure cut off. I thought of that also, I actually beleive thats more than likely what happened, I appreciate all the input. I'll do a triple evac when I get back there...in the meantime I'll keep you posted as to what ends up happening with that .....thanks again

[Randy S.]

Just kidding.

A lot of stuff these days has very fine mesh screens in front of stuff like captube/checkvalve flow control devices. I've seen more than once an installation run for a while then suffer from lack of liquid flow at these screens, due to brazing without a nitrogen purge. Improper evacuation seems to make it that much worse.

I inherited one where it didn't settle down until I installed a liquid drier. The gunk just kept coming.

Also be sure your hoses are mating up properly with the goofy Schrader fittings found on some of the Asian stuff. Especially with the new "low-loss" hoses.

Give it a little extra time on the vacuum pump after you get it tight. Find out how low your pump will go and get as close to that as you can.

[Airmechanical]

you got SLUDGE in the system,its probably everywhere
cond,evap,and lines, you will be lucky if you dont have to
change ALL the components.



.

[DeltaT]

my run is about 65 feet long

Please, go read the install instructions and do yourself and the customer a favor. There is no sense in doing anymore work until the basics are corrected.

[john77420]

the first think i would do is remove all flare fittings in the system, you will get a leak in the future no matter what you do. the next thing i would do is get a chemical purge kit form United Ref and do a chem purge, this stuff really works, i used it on a unit that was full of carbon for the factory (carrier). and it got alot of carbon and the unit ran fine. i would watch out were you put the drier, because the small line leaving the unit is the expansion line not the liquid line.

[esornivram]

get lots of nitrogen, start purging out each component, line set, do it several times each, pressurize to max pressure, then open an part/fitting. let it push out the sludge/moisture, yes it sound like compressor pumped out it oil and its all full or water/ moisture, untill you get it all out the problem will come back, oh yea while putting in nitro do leak checks every where

[just_opinion]

I had a Lennox heat pump with a broken suction line in the attic (soft solder). It ran on heat mode for the whole weekend without freon but 100% attic air. Who knows how many time the compressor shut down due to over heat. Monday came, one of the tech did a quick vaccuum (one cigaret long and the pump sound low). He added freon and ran the unit. Nothing but ice on the outlet of the TXV on cool mode.

We end up pulling vaccuum on this baby for more that 30 hours. Got down to 460 microns. The unit still rocks for two years.

Vaccuum your system throughly man.

If you don't have micron gauge and properly use it, you might as well purge the system. I bet it will run better then having 6 hours vacuum WITHOUT ANY TYPE OF MEASUREMENT to see how well your vacuum is. Becuase chances are your suck air into the system