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Thread: Problem with ac

  1. #1
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    Unhappy Problem with ac



    l`ve replaced a faulty compressor.Got the unit running and founded that the pressures are suction 500kpa and discharge 2000kpa R22.l`m not getting a sweat back and the tx value superheat is 16k which is the best l could get it down to.The problem is that its not cooling all that good supply temp is 19.9c and return is 26c.Ambiet temperature is 36c.The compressor is a reciporacating and the top of the compressor has to be cool but its really hot.Would anyone help thanks James



  2. #2
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    Re: Problem with ac

    Did you pressure test the system, vac and weigh in the correct refrigerant charge.

    PP

  3. #3
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    Re: Problem with ac

    Did you evacuate properly?
    Is this a critical charge system (ie split system with expansion device in the outdoor)?

  4. #4
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    Re: Problem with ac

    Quote Originally Posted by james770 View Post
    l`ve replaced a faulty compressor.Got the unit running and founded that the pressures are suction 500kpa and discharge 2000kpa R22.l`m not getting a sweat back and the tx value superheat is 16k which is the best l could get it down to.The problem is that its not cooling all that good supply temp is 19.9c and return is 26c.Ambiet temperature is 36c.The compressor is a reciporacating and the top of the compressor has to be cool but its really hot.Would anyone help thanks James
    1 Make/model of unit
    2 Was compressor like for like replacement
    3 What type of tx valve/orifice size
    4 Were any driers replaced
    5 Why touch tx valve adjustments
    6 Ammount of refrigerant charged (New & Clean??)
    7 original failure of compressor (Why replaced??)

  5. #5
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    Re: Problem with ac

    Yes l`ve pressure tested system with nitrogen also vaccum the system .l`ve got new liquid line drier also a suction burnt out drier installed.Its a AirFact unit and the tx-value is in the outdoor unit.The reason why l replaced compressor is because it was running inefficent with a high suction pressure which possibly the suction reed is damaged and also the refrigerant had a funny smell to it.

  6. #6
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    Re: Problem with ac

    Is the condenser blocked? Fan operating full speed and right direction?

    Is there anything on the discharge side that could case a problem? mufflers, reversing valves etc?
    Is there welds in small pipes that could be blocked?
    Just thinking out loud here, but it seems there's a refrigerant flow restriction on the gas side discharge (between compressor and condensor) as that pressure is way too high.

    If there is, after the system cools down a bit, measure the temperatures of the pipes going into and out of it after the system has run for 10 or so minutes, eg compare temps muffler in, muffler out.
    Or discharge rv in temp in, discharge side rv out, and suction side rv in and suction side rv out.
    Last edited by paul_h; 29-01-2009 at 09:41 AM.

  7. #7
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    Re: Problem with ac

    check subcool temp ...
    condeserfan ok ??

  8. #8
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    Re: Problem with ac

    Thats quite a high ambient mate, if those condensor fans arn't going properly or if the coil isn't clean you will have problems.
    Im not familiar with that brand of unit but does having the service panel off cause the condensor fans to bypass air around the coil?

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