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  1. #1
    Join Date
    Jan 2008
    Location
    melbourne aus
    Posts
    80

    Thumbs up problem with trane chiller

    hi guys,
    I have a problem with a trane chiller ccga series about 12 years old. it a chiller that only runs in winter and builds ice running glycol. it has a rcm reciprocating chiller control module which may be a lil dodgy. the unit will run then cut out ntoa or ntob which is high nmotor temp a or high motor temp b, they do it it in 4 hours and the fault code will alternate, buzzed out thermistors in motors and they are all fine any ideas would be a great help
    .

    Luke

  2. #2
    Join Date
    Oct 2001
    Posts
    6,966

    Hmm

    is that a CGAC air cooled chiller with a W7900 panel within the control panel those resisters your ringing out just proof the tranr GUARD PAK with the red button on it to close M1-M2 during the ON cycle....did you megger out the compressor windings and for both to do the same thing per circuit...possible short cycling might heat up the resistors to trip as they should.if you have a generic panel running that thing they can only look at NO/NC contact points from the chiller to give you those diagnostic faults,,,full model number if you can.
    "when in doubt...jump it out" http://www.youtube.com/watch?v=U1qEZHhJubY

  3. #3
    Join Date
    Jan 2008
    Location
    melbourne aus
    Posts
    80

    trane

    thanks for the reply , have changed gaurd pack, meggered motor all seems fine,

  4. #4
    Join Date
    Aug 2006
    Location
    Mixing oil and fire with a big spoon.
    Posts
    4,524
    Quote Originally Posted by cool_tech View Post
    hi guys,
    I have a problem with a trane chiller ccga series about 12 years old. it a chiller that only runs in winter and builds ice running glycol. it has a rcm reciprocating chiller control module which may be a lil dodgy. the unit will run then cut out ntoa or ntob which is high nmotor temp a or high motor temp b, they do it it in 4 hours and the fault code will alternate, buzzed out thermistors in motors and they are all fine any ideas would be a great help
    .

    Luke
    what do you mean that you "buzzed out the thermistors"? if you are tripping on high motor temp, check your suction super heat, voltage and amp draw.

    let us know.

    good luck.
    "If you pull one more stunt like you just pulled with Tommy, you won't have to get on a plane because I will personally kick your ass from here to Korea!" - Best of the Best

  5. #5
    Join Date
    Jan 2008
    Location
    melbourne aus
    Posts
    80
    the manual says that if it cuts out on that fault code that there is a temp fault from the thermistors.

  6. #6
    Join Date
    Jan 2008
    Location
    melbourne aus
    Posts
    80
    thanks you for the reply, it is as if there is a fault that causes the circuits toi go down which ever circuit is started first will bomb out , it is a robert shaw module. meggered out both compressors both ok. when testing ran like a trane for a good 3-4 hours went down on high temp circuit a reset circuit b fired up ran for 3 hours then went out high temp. checked program settings all ok. has any one heard of the thermistors playing up,

  7. #7
    Join Date
    Aug 2006
    Location
    Mixing oil and fire with a big spoon.
    Posts
    4,524
    sorry. i could not find any info on your unit in my database. so i looked for it outside of my database . there is a service bulletin on those if the unit is pre-January 1996 build. it talks about a centrifugal compressor. what is the compressor model number? what about the whole unit model number?

    good luck.
    "If you pull one more stunt like you just pulled with Tommy, you won't have to get on a plane because I will personally kick your ass from here to Korea!" - Best of the Best

  8. #8
    Join Date
    Jan 2008
    Location
    melbourne aus
    Posts
    80
    hi, there are two reciprocating compressors one with 8 cylinders the other with 6

  9. #9
    Join Date
    Mar 2005
    Location
    Indiana
    Posts
    160
    I had a little trouble with your original disciption of the problem but I assume you are tripping out on reset relay which could be other things than motor temp. We have a problem all the time with those units. What could be is that when one compressor is running and the second compressor pulls in the contactor jars the panel so hard that the vibration trips the reset relay. There really isn't a problem, just remove the screw holding the reset relay in place and let it hang by the wires or loosly wire tie it to the wire harness. Have had this fix the problem every time. It's usually worse on the part winding start compressors because of two contactors pulling in.

  10. #10
    Join Date
    Oct 2007
    Location
    california
    Posts
    57
    As Always looking stated with reset relay but the fix we would do would be to chang out reset relay or parallel relay with it.no more problems.good luck

  11. #11
    Join Date
    Dec 2003
    Location
    45th Parallel
    Posts
    957
    Is problem fixed?
    If not check this:
    motor temp sensor wires probably run in same conduit as motor leads.
    Pull all 4 motor sensor wires out, and 2 oil pc wires.
    Check for wear. Run a separate 1/2" flex conduit for new wires if needed.
    Quite a few years ago I had a 60 ton R tripping intermittently for no reason.
    After checking superheat, subcooling, DGT, amps, pressures, etc., even pulling motor term plate to make sure sensor leads were securely attached.

    I am not sure what made me do it, but I pulled above mentioned wires out and found that one of the motor sensor wires had been rubbing on the flex and worn thru all strands except for one. The one remaining strand was broken, but still making contact. Occaisionally it would separate due to vibration and trip off on motor temp.
    The only thing the black box looks at is resistance, no current flow in those wires, so it doesn't take much of a connection to stay on line. It won't blow a fuse even if shorted to grnd cuz there is no voltage on those wires.
    Something to think about if your still having problems and have checked everything else.

  12. #12
    Join Date
    Dec 2007
    Location
    Oregon
    Posts
    525
    Sounds Like a good one???? I have had quite a few gaurdpaks fail over the years. Did you say both compressors are tripping....might be a coincidence but I wonder if you have a System problem....might want to check and log...compressors trip out after 3 to 4 hours,hmmmm?

  13. #13
    Join Date
    Jan 2008
    Location
    melbourne aus
    Posts
    80
    thankyou for your help guys will try all sugestions when back on site

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