Help wiring a 3 Phase motor with no wire numbers

Discussion in 'General Electronics Chat' started by Houdini, Nov 18, 2008.

  1. Houdini

    Thread Starter Member

    Dec 13, 2007
    10
    0
    I am looking for anyone that can help me wire a 3 phase, 12 wire motor that someone has messed up the wire numbers. So the general wiring diagram on the nameplate will not work. (High Voltage (480volts)


    L1 - T1 - T12
    L2 - T2 - T10
    L3 - T3 - T11
    T7 - T4
    T8 - T5
    T9 - T6

    Is there a procedure I can use to get my wiring correct?

    Thanks
     
  2. beenthere

    Retired Moderator

    Apr 20, 2004
    15,815
    282
    I got 439,000 hits on "3 phase 1112 wire motor" using Google. Try this one - catalog.wegelectric.com/img/Wiring_Diagrams.pdf.

    You will obviously need a meter to check the wiring.
     
  3. Houdini

    Thread Starter Member

    Dec 13, 2007
    10
    0
    Beenthere,

    Thanks for the reply. I looked at the wiring diagrams and they show the same thing that is on my nameplate for my motor. The issue is that my motor has no wire numbers for me to use with this diagram.So, I will need to find out how to determine which wires go to which windings or which windings to attach together.

    Thanks
     
  4. beenthere

    Retired Moderator

    Apr 20, 2004
    15,815
    282
    That is where a meter comes in handy. You will have to ring it out with an ohmmeter.
     
  5. Houdini

    Thread Starter Member

    Dec 13, 2007
    10
    0
    I just got off the phone with the engineering department at Leeson. They just old me that if the wire numbers are not on the wires (or if they have been mislabled), there is no way to determine which winding is which. All you can do is determine which wires to go each winding by using an ohm meter but determining which windings to attach together can not be done. They said I have to bring the motor back to the rewinder and get them to open it up and check the wires and re number them.

    Does this make any sense? or are they just blowing smoke?:confused:

    Thanks
     
  6. markm

    Member

    Nov 11, 2008
    16
    0
    Unfortunately, it does make sense. With 12 wires, you've got 6 windings. They have to be connected in series or parallel as required for the voltage applied. (From the label that you reproduced, apparently it's series for 480V.) You can ohm to find six wire pairs for six windings, but you can neither tell which windings are at the correct angle to be be series-connected, nor even which direction to connect them in. (That is, whether you're connecting a coil in forward or reverse...)

    I can think of some things I might try in a well-equipped lab, like energizing one winding, using an external motor to spin the shaft, and measuring the phase and voltage induced on the other windings. But I don't know where you'd find a lab with the right equipment, and (with zero experience in such work) it seems entirely reasonable that it would take an engineer longer to work things out this way than it takes a technician to take it apart and trace the wires physically.
     
  7. Houdini

    Thread Starter Member

    Dec 13, 2007
    10
    0
    That makes total sense!...

    Thanks for the help.
     
  8. Houdini

    Thread Starter Member

    Dec 13, 2007
    10
    0
    wow, impressive.... I did send this Motor back to the motor rewinder that did it.. Hopefully they can figure it out once they get it apart but if they can't and I get it back the same way, I would be interested in trying your suggestion.. Sounds fun..

    Thanks again
     
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