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  1. #1
    Join Date
    Mar 2009
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    Hmm Walk in freezer problem

    I just replaced walk in freezer condensing unit two days ago. We replaced condensing unit only but we left the existing evaporator in place. It used to have Copeland semi-hermetic compressor but this time around we went with Techumseh AVA2510ZXTLN, R-404 system exact match for the Copeland. Existing system was 404 also. So anyways cut lines removes the old unit, install new. Brazed couple of joints, condensing unit came charged with nitrogen, left the nitrogen in unit till brazing was done. Opened the service valve on condensing unit, let nitrogen circle around, make sure no leak. Pulled a vacuum, start charging system on high side but noticed low side pressure rising, but power for evaporator de-energized, power for evaporator coming from condensing from DT. Ok weird my liquid line solenoid not holding, ok pumped down, installed new solenoid, re-start same thing not holding. At this point two bad solenoid, possible but not likely. Check all electrical, everything checks ok, even when power removed from coil, still solenoid not holding. At this point I am second guessing my self, did I overheat the valve. Is it possible to have to bad valves. So I come back today with third valve and I even install access port after solenoid valve to confirm its not holding, sure enough when I put system in defrost, solenoid de-energized starts pumping down but only to 15 psi, cut out set at 10 psi, when I look at my pressure after solenoid it stays at 15 psi, not holding slowly bleeding through and same result. So at this point, moisture in system causing valve to stick? Look at SG solid green, no indication of moisture. Is there moisture in system or there is something else going on? But when I pumped down at recivier, compressor pumps down and shuts off to eliminate bad valve plate. The pressures are normal 80F ambient 275 hS 25 low side. I watched make 0F in no time, but it just wont pump down. I am not sure what I a missing here, what could be causing solenoid valves to stick. I even changed the coil on solenoid to eliminate any issues with that. So I am now questioning no that unit came from factory with some moisture issue? Any inputs and help would be appreciated.

  2. #2
    Join Date
    Jun 2018
    Location
    Pensacola, FL
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    Here is a dumb question and I only ask because you sound frustrated with it. Valve flow in the correct direction?
    Now for the result of a similar problem on my end: Electromagnet is potentially magnetizing your stem even when de-energized. Sporlan solved it with a brass washer that goes on top of the stem before the coil is installed so there is no direct contact to mess with the polarity of the metal. It worked flawlessly.
    Third silly thing: Did you actually check voltage at the coil and each leg to ground for partial voltage? A DT relay can fail.
    Fourth: Is the valve rated for the volume of a 2 1/4hp compressor?
    That's all I got. I am leaning on the sporlan brass washer.

  3. Likes tmt0269 liked this post
  4. #3
    Join Date
    Mar 2009
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    Thread Starter
    Quote Originally Posted by I.C.E. View Post
    Here is a dumb question and I only ask because you sound frustrated with it. Valve flow in the correct direction?
    Now for the result of a similar problem on my end: Electromagnet is potentially magnetizing your stem even when de-energized. Sporlan solved it with a brass washer that goes on top of the stem before the coil is installed so there is no direct contact to mess with the polarity of the metal. It worked flawlessly.
    Third silly thing: Did you actually check voltage at the coil and each leg to ground for partial voltage? A DT relay can fail.
    Fourth: Is the valve rated for the volume of a 2 1/4hp compressor?
    That's all I got. I am leaning on the sporlan brass washer.
    Now that you mention the brass washer, I remember couple of years ago when I was doing market refrigeration we had that problem and we did install brass washer and that did solve the problem. As far as your other suggestions its pointing in right direction, as far as voltage goes, I did disconnect power to the coil, both legs and it still was blowing by.

  5. #4
    Join Date
    Mar 2008
    Location
    kansas
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    Got number off the valve sounds like oversized valve not enough pressure drop. If your positive the direction is correct we refer to this as brother ni. Long story
    Honeywell you can buy better but you cant pay more

    I told my wife when i die to sell my fishing stuff for what its worth not what i told her i paid for it

  6. #5
    Join Date
    Jan 2016
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    Sounds like you have a liquid line/suction line heater exchanger leaking into itself.

  7. Likes trippintl0 liked this post
  8. #6
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    Mar 2009
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    Thread Starter
    Quote Originally Posted by VanMan812 View Post
    Sounds like you have a liquid line/suction line heater exchanger leaking into itself.
    I don't think there is one, unless its hiding somewhere on top of the box. But the original valve was an alco solenoid and it was doing same thing, than the three new ones are sporlan, so I don't think its a sporlan issue. There is got a be some kind of voltage feed back to keep that valve slightly open. I keep you guys updated tomorrow.

  9. #7
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    Mar 2008
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    kansas
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    How can it be a voltage issue when you said it was still feeding when electrical is disconnected or did I read that wrong.
    Honeywell you can buy better but you cant pay more

    I told my wife when i die to sell my fishing stuff for what its worth not what i told her i paid for it

  10. #8
    Join Date
    Mar 2009
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    Thread Starter
    Vanman you where right, there was a heat exchanger on top of the box. Cut it out and works great. Thanks for your help guys!!

  11. Likes VanMan812 liked this post
  12. #9
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    Mar 2008
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    kansas
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    Wow miss Cleo doesn’t have sh#t on you vanman don’t know if your lucky or good,but I would get a lottery ticket.
    Honeywell you can buy better but you cant pay more

    I told my wife when i die to sell my fishing stuff for what its worth not what i told her i paid for it

  13. Likes VanMan812 liked this post
  14. #10
    Join Date
    Jan 2016
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    I’ve seen it a couple times before, that’s all.

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