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  1. #1
    Join Date
    Feb 2007
    Location
    Fairhope, AL
    Posts
    17

    CVHE Phase Imbalance

    Is there a reason known that will cause a CVHE with U2CP controls will repeatedly shut down on phase imbalance when by all appearances the phases seem to be fine?

  2. #2
    Join Date
    May 2007
    Location
    Surrey BC
    Posts
    118
    Check your CT's

  3. #3
    Join Date
    Dec 2004
    Location
    Mid-west
    Posts
    567
    What are the phase reading, leg to leg??

  4. #4
    Join Date
    Jun 2007
    Location
    United Kingdom
    Posts
    4

    CVHE phase imbalance

    Trozum,
    The CT's are wired directly into the starter module. If all the readings on the ct's check out and there is no phase imbalance when the chiller is operational it may be the stater module. Depending on the age of the chiller there were a lot of starter module failures when UCP2 was launched. If you have a factory mounted starter with Cutler switchgear it could the contactors. On older chillers there was a factory problem with the shading rings on the Cutler contactors and some failed earlly while others operated for 10+ years before failing.

    Cheers
    Paulh

  5. #5
    Join Date
    Dec 2004
    Location
    Chicago area
    Posts
    1,439
    There is a Potential transformer( you may have three depending on sales order) that checks phase to phase voltage that may cause trouble if there is a loose connection also there are 3 Current tranformers that are wired to the compressor module. Check the resistance. They should all be the same. Check the meg ohms on compressor and phase to phase ohms. You may read phase imballance b/c of amperage imballance 15 percent off of average will trip.

  6. #6
    Join Date
    Aug 2006
    Location
    Mixing oil and fire with a big spoon.
    Posts
    4,268
    Three currents supplied to the Starter module are monitored for unequal Amp
    draw. An imbalance in the motor amp draw can cause the motor windings to heat up. This protection can not be disabled or removed.

    Corrective Action:
    1 Check for defective or incorrect CTs.
    2 Replace Starter module, for possible bad CT input.
    3 Local power company problem.

    give us some specs (model Number, ct number, voltage, etc) and we can point you in a better direction. what are your voltages and amperages?
    my 1st time jumping out of a plane...http://youtu.be/Kv38G0MHsGo

  7. #7
    Join Date
    Mar 2004
    Location
    ottawa canada
    Posts
    2,024

    Cvhe

    Check all the ct"s and pt"s check the starter contacts .Try a themal scan of the starter with the chiller running it could be as simple as a loose starter connection on one of the motor leads. The resistances off the PT's and the CT's should all be fairly close

  8. #8
    Join Date
    Feb 2007
    Location
    Fairhope, AL
    Posts
    17
    Did all the above but after comparison readings between UCP2 and handheld meters I believe problem to be in starter module(Circa 1995).
    AMPERAGES and VOLTAGES ARE READING 25 TO 30 % DIFFERENCE BETWEEN METERS AND UCP2.

  9. #9
    Join Date
    Feb 2007
    Location
    Fairhope, AL
    Posts
    17
    Thanks for all your replies. The Chiller is a CVHE 056 built in 1987 and retrofitted in 1995(approx) at a local Naval Facility.The readings between actual amperages/voltages and what are displayed on the UCP2 make me believe replacing the starter module is my best bet while coordinating with base power people to "clean up" inxoming power. Thanks for the input, I will pass along results.

  10. #10
    Join Date
    Aug 2006
    Location
    Mixing oil and fire with a big spoon.
    Posts
    4,268
    Quote Originally Posted by trozum View Post
    Thanks for all your replies. The Chiller is a CVHE 056 built in 1987 and retrofitted in 1995(approx) at a local Naval Facility.The readings between actual amperages/voltages and what are displayed on the UCP2 make me believe replacing the starter module is my best bet while coordinating with base power people to "clean up" inxoming power. Thanks for the input, I will pass along results.
    the only other thing that i would check first, is the "Overload Settings". just to make sure that nothing got changed (or changed itself). make sure the CT's ohm out properly. other than that, a new starter module may be needed.
    my 1st time jumping out of a plane...http://youtu.be/Kv38G0MHsGo

  11. #11
    Join Date
    Feb 2007
    Location
    Fairhope, AL
    Posts
    17

    CVHE Phase Imbalance

    As we say in the Southland,"Preciate Ya"

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