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  1. #1
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    Rack refrigeration system

    Rack refrigeration system
    How compressors cut in and out in a multi compressor rack refrigeration system ?
    Is it working based on superheat?
    I am new in refrigeration ,
    I noticed on a rack controller 'suction temp. -35°C and discharge temp. 40°C ( that was a freezer )
    How can we know the refrigerant charge is enough in a rack system ?

  2. #2
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    Quote Originally Posted by faisalfadak View Post
    Rack refrigeration system
    How compressors cut in and out in a multi compressor rack refrigeration system ?
    Is it working based on superheat?
    I am new in refrigeration ,
    I noticed on a rack controller 'suction temp. -35°C and discharge temp. 40°C ( that was a freezer )
    How can we know the refrigerant charge is enough in a rack system ?
    Who’s Rack?

  3. #3
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    Thread Starter
    Arneg refrigeration system
    Compressor controlled by Carel controller.
    Suction pressures transducer , liquid line pressure transducer, suction temp sensor are connected with controller

  4. #4
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    I assume it's done by a signal from a suction probe.

    Which Carel controller do you have? pRack perhaps?

    Is there User manual available online for this unit?

  5. #5
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    Typically the rack controller is set for a certain suction pressure based on the coldest load. But some are set up to float the suction pressure based on case temps.

  6. #6
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    As to your last question, you want to see around 30 to 40 % receiver when everything is working. But don't immediately adjust charge if it isn't! First make sure all controls and valves are operating and set correctly, that gas could be hiding out somewhere else.

  7. #7
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    Thread Starter
    This is the controller is used in the rack
    https://img.ikincielim.com/iel_Resim...er/1259540.jpg

  8. #8
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    Thread Starter
    Suction line and compressor body getting frost

  9. #9
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    Quote Originally Posted by faisalfadak View Post
    This is the controller is used in the rack
    https://img.ikincielim.com/iel_Resim...er/1259540.jpg
    I'm sorry

  10. #10
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    Quote Originally Posted by faisalfadak View Post
    Suction line and compressor body getting frost
    Do you have gauges installed to check those pressures and temperatures on a suction line?

    Which part of the suction line is frosting? The suction header, or also the pipe before the collector?
    Do you have a suction strainer installed?
    How many compressors are frosting?

  11. #11
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    You need to call a professional.

  12. #12
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    Thread Starter
    The rack is constructed with 5 compressors. 2 of them are switched off due to mechanical noise. Others are running with 0.5 - 0.8 bar suction pressure .
    It is R22 system
    Suction header and compressor suction port is frosting .
    What suction pressure i should maintain ?
    12 - 15 psig enough ?

  13. #13
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    Sep 2009
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    See my above post.

    You need to know your coldest load to know your sst

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