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  1. #1
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    Apr 2005
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    3 Cabinets 1 Cold-Well ,Common Condensing Unit.

    3 cabinets have a Liquid Line solenoid to cycle off on temperature , which all 3 hold well. The Cold-Well Solenoid is controlled by a simple Rocker-Switch , the customer leaves this well on 24/7.
    When cases cycle off , system runs until Condensing unit cycles off on LP ,, another load will open which then raises LP & Condensing Unit continues its duty , which I would assume would be normal for if this did not happen the Condensing unit would run 24/7 with the cold-well refrigeration circuit still in play.

    Issue now is customer states that the well is not as cold as originally was.
    Sight glass is 1/2 full when all loads open & drops to a trickle when 3loads drop off. Went leak hunting & no leaks found ,,, found solenoid coil cracked & fitted magnet to this circuit but now suspect the solenoid slide & spring maynot be opening fully. Also thinking that this maybe the way it is intended to work for if the pressure in the well circuit was to stay up the condensing unit would only have 4 breaks of 1hour when defrost timer asks for it.

    Thoughts , R22 145Kpa LP , 1200Kpa Hp with only the well circuit in play.
    Cases all have TXV's ,, unsure of well (I'm going to have to see now ,,just overlooked that). Has anybody seen a TXV on a Cold-Well ? There is a removable plate I spotted underneath the well which could hide a valve.
    Condensing Unit is Kirby M:AJ34MGB1.
    The primary function of the design engineer is to make things difficult for the fabricator and impossible for the serviceman.

  2. #2
    Join Date
    Aug 2002
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    Southold, NY
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    Cold well should be turned off every night for defrost.
    3 ? Cases with solenoids ? Install EPR's and let the condensing unit cycle on LP control.

  3. #3
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    Thread Starter
    The setup has been operating this way for 5+ years that I am aware of & being in a kitchen environment space is very limited to install EPR's.

    There are 4 cabinets on the circuit , 1 of which has a Cold-Well at the top & a Cooler at the bottom ,,, so there are 5 Liquid-Line Solenoids in total , 1 for each load.


    Advised the customer the well should be turned off at end-of-trade everyday. They tell me that they only switch-off every couple of weeks to defrost.
    The primary function of the design engineer is to make things difficult for the fabricator and impossible for the serviceman.

  4. #4
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    Aug 2002
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    How can you maintain SH at the pump if the solenoid valves are closed and only a small load is running?
    Operating wrong for 5 years

  5. #5
    Join Date
    Jun 2003
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    Chicago, IL
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    The LPCO should be set to the desired SST of the cold well. When the cold well reaches that temp/pressure and no other circuits are active, the compressor will shut off.

    At least this is how it's done on many pizza prep tables.

  6. Likes Freezeking2000 liked this post.
  7. #6
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    Quote Originally Posted by pecmsg View Post
    How can you maintain SH at the pump if the solenoid valves are closed and only a small load is running?
    Operating wrong for 5 years
    Engineered wrong. Lots of pizza prep tables or semi custom built-ins are operated this way. Your right, it's not the correct way. I think the reason the pumps last as long as they do in systems like these, where a potential low SH can happen, is because the amount of time where ONLY the cold well is running is extremely minimal.

  8. #7
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    I have seen lots of cold wells with a TXV. Usually in a system like yours the cold well has its own T'stat or LPC.

    And like pecmsg said, the cold well needs turned off EVERY night.

  9. #8
    Join Date
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    Thread Starter
    Quote Originally Posted by pecmsg View Post
    How can you maintain SH at the pump if the solenoid valves are closed and only a small load is running?
    Operating wrong for 5 years
    Agree totally , but because the system works & I use that word loosely no money will be spent to redesign it.

    Craig1
    Exactly what I was thinking ,, so now I could be looking at a restricted or failing TXV I'm thinking.

    VanMan812
    Only the LP at the Condensing Unit is the only control I can see that would somehow control the well ,,, as stated it only has an on/off switch for the solenoid & as stated before ,customer leaves the well on 24/7 even though advised should be turned off at end of trade. I'm thinking the continuous running of the well has plugged the TXV strainer or the internals are worn due to excessive use.
    The primary function of the design engineer is to make things difficult for the fabricator and impossible for the serviceman.

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