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  1. #1
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    unit wont go below 48f, yes set temp is 35f



    404a system, unit will not go below 48f box temp.
    Compressor is very cold, very low low side pressure, very low high side pressure, suction line cool
    filter drier slightly warm, liquid line slightly warm, condenser discharge line slightly warm, discharge air
    is slightly warmer than ambient. Total superheat is high but box temp was 48f.
    adjusted the TEV from 1 turn in 1 turn increments to 4 turns open, at every setting the box still would
    not pull below 48f.
    Is this a bad TEV or bad compressor???



  2. #2
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    Re: unit wont go below 48f, yes set temp is 35f

    Discharge line slightly warm? Strange. It must be hot. What is suction superheat?

  3. #3
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    Re: unit wont go below 48f, yes set temp is 35f

    Check your compressor valves.
    What is the currant draw compare to compressor label?
    Any head pressure control?

  4. #4
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    Re: unit wont go below 48f, yes set temp is 35f

    If your unit is integrated AC package,it may some cold(conditioned) air leakage from cooling chamber to condenser.
    otherwise you,d better to look for something wrong in compressor.
    S.P

  5. #5
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    Re: unit wont go below 48f, yes set temp is 35f

    low charge?

  6. #6
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    Re: unit wont go below 48f, yes set temp is 35f

    If the compressor wasn't pumping well the suction pressure would be higher than normal not lower.

    Suspect a shortage of refrigerant, a restriction or a failed txv.
    Mostly found in Oxfordshire, UK :)

  7. #7
    ammoniabreath's Avatar
    ammoniabreath Guest

    Re: unit wont go below 48f, yes set temp is 35f

    sounds like lack of load is evap fan running , is evap iced up/ or dirty causing lack of air flow, have you got a full charge of gas, what is suction superheat, what compressor is it, has it got loaded cylinders. Give me as much info as you can and i will help you resolve issue.

  8. #8
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    Re: unit wont go below 48f, yes set temp is 35f

    Thanks to all who replied
    It was a bad TEV, replaced it, now the unit pulled down from 80f to 35f in about 10 minutes
    guess the TEV was in a stuck open position

  9. #9
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    Re: unit wont go below 48f, yes set temp is 35f

    could you give us these information to give you right suggest .

    outside temp.( in condenser position )
    room temp.
    suction pressure
    discharge pressure.
    is side glass is full.
    compressor size with current (A) with voltage on that.
    does compressor has a sound or vibration on working time.
    when compressor goes off , does suction and discharge pressure move to be equal fast or it takes time.
    Last edited by mbc; 03-02-2012 at 04:01 PM.

  10. #10
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    Re: unit wont go below 48f, yes set temp is 35f

    Quote Originally Posted by monkey spanners View Post
    If the compressor wasn't pumping well the suction pressure would be higher than normal not lower.

    Suspect a shortage of refrigerant, a restriction or a failed txv.
    I also agree with you.
    To make progress is never good enough, I want to do better and better and better

  11. #11
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    Re: unit wont go below 48f, yes set temp is 35f

    Norsk, good one. That's why we asked about suction superheat.

  12. #12
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    Re: unit wont go below 48f, yes set temp is 35f

    Hi Norsk, thanks for feed back, that your problem is sorted

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