A simple device that can detect either 3-phase national or 160kva generator supply.

Discussion in 'The Projects Forum' started by Olushola Adedoye, Aug 19, 2012.

  1. Olushola Adedoye

    Thread Starter New Member

    May 19, 2012
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    Please help me.Is it possible to pass frequency through the neutral cable of 3-phase 4-wire armod cable? If it is possible,is there any device that can detect that frequency and use it to switch on the contactor?
     
  2. praondevou

    AAC Fanatic!

    Jul 9, 2011
    2,936
    488
    You'll need to provide much more details if you want an answer containing useful information.

    What voltage, what contactor, generator/grid power switching sequence/timing, purpose of what you want to do.
     
  3. Olushola Adedoye

    Thread Starter New Member

    May 19, 2012
    3
    0
    DRW PAINT34.JPG
    Please I need a device that can detect either 3-phase
    national or 160kva generator supply in order to use it switch on the
    contactor(we use 220v,50HZ,3-phase 4wires armod cable) Attached is the circuit diagram.
    Thank you.
     
  4. cork_ie

    Member

    Oct 8, 2011
    348
    58
    Your Circuit doesn't make a lot sense to be honest. If you are using a 160KVA Generator I assume that your circuit is designed to take anything up to 500A.
    It is unlikely that you will be switching that through a changeover switch and that this is the function of the contactors.
    I also suspect that you are not using 220V 50 HZ three phase , but 220V phase to neutral which is a different story. I have never heard of any country with 220V 50HZ across phases

    Therefore what I think you want is : A supply to your changeover switch that will select whichever contactor you care to operate. This is a little different to your drawing and your original question.
    If that is the case you will need to supply your contactor coils - with the correct voltage. You will need interlocks fitted on your existing contactors or alternatively interlocks on slave contactors to absolutely ensure that what ever happens you cannot under any circumstances turn the two contactors on together or feed the supply from the mains into the generator or vice-versa.
    I always appreciate posters learning for themselves and would urge them to keep trying until they get their project working.
    In this case however , you are working with very dangerous voltages of approx 400 Volts phase to phase. (550 V peak to peak!!)
    Please I beg of you if you are not 100% sure of what you are doing , get someone qualified to do it
    . You could electrocute yourself or someone else
     
    Last edited: Aug 20, 2012
    Olushola Adedoye likes this.
  5. Olushola Adedoye

    Thread Starter New Member

    May 19, 2012
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    0
    Thanks for your suggestion.
    I have tested my design with cable connected to change-over generator supply to close the contactor when generator is ON and it worked but I don't want to connect any external cable to power the generator contactor I want a device that can detect through the supply.160kva generator and National supply from change-over is supplying 30-3bedrooms flat through 3-phase 4wire prepayment meter.At 220v and 50hz.There is no way I can give detail design diagram here.What matter is detecting which supply is on when change-over is changed or ON.Can it possible to pass frequency through neutral cable when generator is ON and a device to detect and use it to switch ON generator contactor.
     
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