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Thread: Motor Taps Delta/Wye?

  1. #1
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    Motor Taps Delta/Wye?

    I am currently working on a greenhouse that is manufactured entirely in Israel. There are 6 motors for shade curtains. The syatem supplying the building is a 120/208Y 3Ph System. I hooked up the motors correctly according to the diagram sent with the motors which was typical for a low voltage 3 Ph motor tap for a Y system. When we tested the motors originally the motors ran fine but were unable to completely handle the load(they stopped half way up). when we contacted the rep from Israel he said we needed to hook up the motor as if it were a Delta system and when we did they worked perfectly. Problem being that i can't understand why! Same voltage just tapped as if it were a delta system when it is actually Y. if i were to do this on a motor manufactured in the US what would be the result?. any info would be appreciated!!
    signed, completely confused!!!

    [ October 01, 2003, 09:18 PM: Message edited by: justin ]

  2. #2
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    Re: Motor Taps Delta/Wye?

    How many motor leads?

  3. #3
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    Re: Motor Taps Delta/Wye?

    Bennie
    A 3-phase motor that can change from a Y to a delta would be a 9 lead wouldn't it?
    Of course there are these new 12 lead Eco motors but the same would still apply if you didn't use the soft start winding.

    I thought Israel used the European voltages and frequency's?
    Wayne A. From: N.W.Indiana
    Be Fair, Be Safe
    Just don't be fairly safe

  4. #4
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    Re: Motor Taps Delta/Wye?

    You have to have 12 leads to change from wye to delta on a dual voltage motor.

    The type of supply system (delta or wye) has no bearing on how you connect the motor. You just match the supply voltage to the motor voltage. A delta supply can run a wye motor or visa versa.

    Don
    Don, Illinois
    "It is the first responsibility of every citizen to question authority." B Franklin

  5. #5
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    Re: Motor Taps Delta/Wye?

    A 3-phase motor that can change from a Y to a delta would be a 9 lead wouldn't it?
    If a three phase motor is "delta-wound", that is, designed to operate with the three windings delta connected, it will not operate correctly if the windings are wye connected. Each phase would get only 58% of rated voltage, and torque would be lowered.

    Similarly, a wye-wound motor mistakenly connected delta would have the winding voltage increased by the factor of 1.73, and would be damaged.

    There are motors designed to be started with the windings wye connected (for a few seconds), then changed to delta for running.

    Most general purpose (not multi-speed) three phase motors manufactured in North America fall into one of these categories:-

    3 leads - single voltage - 208 or 575 volts.
    6 leads - single voltage - 208 or 575 volts for wye-delta starting.
    9 leads - dual voltage 230/460 volts
    12 leads - dual voltage - 230/460 volts for wye-delta starting.

    BTW - Israel's standard is 230 volts, 50 Hz.
    Could one assume that equipment intended for export would conform to the standard of the country the equipment is exported to?

    Ed

    [ October 03, 2003, 12:11 PM: Message edited by: Ed MacLaren ]

  6. #6
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    Re: Motor Taps Delta/Wye?

    Ed correct me if I am wrong, you are taking about low voltage connection on dual voltage motors?

  7. #7
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    Re: Motor Taps Delta/Wye?

    you are talking about low voltage connection on dual voltage motors?
    Not sure what your question is.

    The 230/460 volt motor can be used at either voltage with a wye-delta starter, if it has 12 leads.

    The only reason (that I know of) for specifying a 12-lead motor would be for use with a wye-delta starter. Don referred to that above.

    The standard 9-lead, 230/460 volt motor is permanently connected either wye or delta, depending on other design factors, internally, and cannot be easily changed in the field. The 9 leads are provided for changing voltages.

    Ed

    [ October 02, 2003, 01:26 PM: Message edited by: Ed MacLaren ]

  8. #8
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    Re: Motor Taps Delta/Wye?

    Ed there are 6 lead motors that are dual voltage WYE start and Delta run. On 9 lead and 12 lead motors the connection on the high side are the same,4&7 5&8 6&9 and so on. On the low side of the 12 lead motor there is a difference on the connection between WYE and DELTA. Thatis what I was asking if that was what you were taking about?

  9. #9
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    Re: Motor Taps Delta/Wye?

    to answer some ?'s, there were only 3 leads. i was told the motors were tested Y/360V in israel @ 50hz. I have since heard that there can actually be a difference in the torque rating of the motor depending on the internal windings and how it is tapped. definitely something new to me, and i am still interested in any other info or other similar experiences. i appreciate what has been posted so far! justin

  10. #10
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    Re: Motor Taps Delta/Wye?

    to answer some ?'s, there were only 3 leads
    Justin, I'm curious.

    What changes were made to the motor connections, to make them work properly? You said the motors only have three leads.

    Ed

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