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  1. #1
    Join Date
    Jun 2003
    Location
    Chicago, IL
    Posts
    4,386

    Wet system ok. Install dryer-txv's freeze up?

    System in question is a tyler meat service case with a remote k- body compressor and a remote condenser. Holds about 50-60 lbs r-22. About a year and a half ago I put a valve plate in it and adjusted txvs to get proper superheat. Also adjusted the LPCO as it was out of calibration and pumping down into a vacuum even though it was set to cut out at 20 psi.

    The sight glass on this system has always been yellow for the 2 years I've serviced this market, I kept intending to change the dryer, but never did because I didn't have time and they had so many other serious issues to take care of. Anyways last wednesday I put in a new c-303 filter. Next day I get a call, case warm. Go there and find both txvs frozen up. Dumped hot water on them and it immediately starts cooling. Moisture indicator was showing light green at this point. Threw in another new dryer and it seems to be ok so far.


    I'm completely puzzled how a wet system can work fine for years and then have moisture related trouble as soon as the moisture level is reduced?

  2. #2
    Join Date
    Sep 2008
    Location
    Western PA
    Posts
    25,551

  3. #3
    Join Date
    Aug 2006
    Location
    st.petersburg,fl
    Posts
    803

    Lightbulb

    It would explain it if you used your torch to unsweat the drier, instead of using tubing cutters.....

    How did you remove the drier ?
    Isn't sanity just a one-trick pony anyway? I mean, all you get is that one trick, rational thinking, but when you're good and crazy, well, the sky's the limit!

  4. #4
    Join Date
    Jun 2003
    Location
    Chicago, IL
    Posts
    4,386
    Dryer was connected with flares, so no torches involved. Just closed king valve, pumped down system, closed liquid valve at outlet of dryer, changed dryer, evacuated dryer and 4 feet of related piping and opened the valves.

  5. #5
    Join Date
    Aug 2006
    Location
    st.petersburg,fl
    Posts
    803

    Lightbulb

    Sorry I failed to see the size of the system when I read your original post and you said the amount of refrigerant or I never would have said that, all I can do is agree with JP then.... When you pulled vacuum did you pull get it to a minimum of 500 microns so your system is dry ?
    Isn't sanity just a one-trick pony anyway? I mean, all you get is that one trick, rational thinking, but when you're good and crazy, well, the sky's the limit!

  6. #6
    Join Date
    Aug 2007
    Location
    Winter Haven, FL
    Posts
    4,364
    If ain't broke don't fix it...
    I guess we see the other side of that equation now...

  7. #7
    Join Date
    Jun 2003
    Location
    Chicago, IL
    Posts
    4,386
    OK, so today i get a call from the same market. packaged meat display case down (not the same case as before) . go there and find all 3 TXVs frozen up.

    Thought about it and realized that just a couple weeks ago i had changed the dryer. Just like the case in the OP, it ran fine until I changed the dryer, then the txv froze up.

    The sight glass on this one was never bright yellow like the case in the OP was. it was a pale green, which turned to a bright green a few days after the filter was installed. the freeze up happened about 2 weeks later.

    as for the meat case in the OP, after defrosting the TXVs twice, and giving the filter a few days to pick up all the moisture, it never had a problem again.

  8. #8
    Join Date
    May 2008
    Location
    Myrtle Creek. Oregon
    Posts
    182
    I have ran into this many times. TXV iceing up. the only way I could remove the moisture is change the oil, and install a hi capasity drier and suction filter. and clean the TXV.
    a stupid question is a question you wont to ask, but don't

  9. #9
    Join Date
    Nov 2009
    Posts
    384
    It has happened to me too.

    One in particular was a low temp Hussmann rack with Carlyle's on it. It would run good for over a year and then all of a sudden several cases had frozen valves.
    We had to replace a compressor one day and water came out of the stator housing of the compressor.

    I have also heard that it can float on top of the liquid in the receiver. I am not sure if that is true or not, I haven't given that one much thought.

    Driers and oil changes were the best way to go for the rack application I had.

    Hmmmmmm, interestingly enough my issues were with R-22 also........
    "Don't wish it were easier, wish you were better"

  10. #10
    Join Date
    Oct 2011
    Location
    East Charlotte Area of NC
    Posts
    421
    Interesting to see this post.

    Many years back, I had a walk in beverage sales cooler with a 5 HP condenser with a can compressor that had been running with little problems well over 10 years. I get a svc call, comp shorted to ground. Owner of the store had another company out a few weeks prior doing a PM, they changed the drier, cleaned condenser/evap, etc. They were busy and could not get to him that day so he called the company I worked for. So, I change the compressor, new drier, pulled evac, started. (At that time did not put a micron gauge on the system, pulled it to 28-30 in/hg and went to lunch) Noticed the sight glass was pale green, almost yellow. I always use high capacity driers, so I figured it would clear.

    Week later, new compressor shorted to ground.
    Sight glass still pale green.

    I got a comp under warranty, pulled the one out, and for the hell of it poured the oil out of the compressor. (I am not sure what possessed me to do that) Of the 20 oz I got, I bet a 1/3 was water. Flushed the system out, new TXV, new drier, new sight glass, new compressor. Pulled evac, pulled down to 350 microns and held overnight. No leaks.

    So, where did this water come from and why did the system run for 10 years with no problem before?

    Never had another problem after that. That one still puzzles me.

    I can't fix it if it won't stay broke..

  11. #11
    Join Date
    Sep 2006
    Posts
    154
    Quote Originally Posted by CRussell1975 View Post
    few weeks prior doing a PM, they changed the drier, cleaned condenser/evap
    Knuckleheads probablly hosed out the coil with the drier off......

  12. #12
    Join Date
    Jan 2012
    Location
    Northern california
    Posts
    65
    A disgruntled contractor. And an oil pump and some water..We had a local guy get burned in Bankruptcy by Lyons restaurants. So he went up to the roof on four restaurants and pumped water into the systems. They caught on after the fourth restaurant had problems. Checked the cameras. And he was arrested.

  13. #13
    Join Date
    Oct 2011
    Location
    East Charlotte Area of NC
    Posts
    421
    Wow.. the power of talking things up.

    Went to a market yesterday, simple call.. cheese island warm.

    TXV's not feeding.

    Pumped down, pulled TXV screens, all clear. Restarted circuit, pulled right down.... my thoughts? "Oh Sh..."

    Whole rack full of moisture.

    Who started this conversation anyway?

    Planning an oil and multiple drier change if the market corporate will allow it.

    I can't fix it if it won't stay broke..

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