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  1. #1
    Join Date
    Jan 2001
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    compressor unloading

    can someone explain what is actually happing inside compressor when compressor unloads. was working on large trane tin can. it had solenoid inside
    cover.when compressor loaded suction went down amp draw up but never totally understood what happens intenally. i guess refrigerant is being bypasses internally. any tricks to troubleshoot/repair. anybody know of any good compressor schools.

  2. #2
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    Apr 2006
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    whats the compressor type, model #, probably either the hot gas bypasses and dumps back into the suction side, or a piston blocks the suction not allowing the compressor to pump any refrig. thus not doing any work. thats about as simple as i can describe it

  3. #3
    Join Date
    Jan 2008
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    It`s kinda like a Dodge MDS engine. When your in the city it uses half of it`s capacity let`s say it`s a 6 cylinder . 3 in the city and 6 on the highway.

  4. #4
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    Jul 2009
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    It depends screw most via slide valve, semi hermetic have a few different ways, Centrifugals by freq and turning vanes modulation etc...........
    “It takes courage to grow up and turn out to be who you really are.”

    - E.E. Cummings

  5. #5
    Join Date
    Sep 2004
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    Kansas City, Kansas, United States
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    semis use either hot gas bypass which is inefficient or suction unloading
    both can be operated mechanically, electric unloader, pneumatic unloader or oil pressure unloader.
    i have not seen one but i have heard of some machines that LOAD when powered up????
    i know that on trane E compressors that operate with oil pressure that they start UNLOADED

    have fun




    Quote Originally Posted by chrishvacman View Post
    It depends screw most via slide valve, semi hermetic have a few different ways, Centrifugals by freq and turning vanes modulation etc...........
    I WILL SELL WORK,GENERATE BUSINESS, GO GET NEW CUSTOMERS!
    YOU SHUT THE HELL UP AND QUIT RUNNING YOUR MOUTH!

  6. #6
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    Sep 2008
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    Western PA
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  7. #7
    Join Date
    Sep 2004
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    Kansas City, Kansas, United States
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    hi JP!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

    i would like to unload a couple of my daughters!!!!!!
    they are a pain in the arse


    Quote Originally Posted by jpsmith1cm View Post
    http://www.hvacrinfo.com/ae_index.htm


    Scroll down to section #21.

    There you will find Copeland's AE bulletins on capacity control.
    I WILL SELL WORK,GENERATE BUSINESS, GO GET NEW CUSTOMERS!
    YOU SHUT THE HELL UP AND QUIT RUNNING YOUR MOUTH!

  8. #8
    Join Date
    Aug 2000
    Location
    Under my tree
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    In a nutshell, the compressor is moving less volume of gas as it unloads. Be it by frequency, guide vanes, slide valve or rendering a few cylinders out of action. JMHO
    Not much to say, just hanging in my shade tree!!!!

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