5 pin 3 phase saw

  1. vwmark

    vwmark Member

    Messages:
    661
    Location:
    North Wales
    Hi - I have just bought a cold cutting saw which I intended to run off my static convertor.
    The issue I have is the saw is 5 pin. 3 supply, earth and neutral.
    I guess the neutral is being used as a return to run the coolant pump.
    The coolant pump is 230/440v so if I took this out the circuit can anyone see an issue running the saw on a 4 pin plug?
    received_2633569513562526.jpeg
     
    Jacktegla likes this.
  2. Seadog

    Seadog Forum Supporter

    Messages:
    6,973
    Location:
    NE London - UK
    If the pump is three phase it doesn't use a neutral.

    upload_2020-8-13_10-47-6.png
     
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  3. daleyd

    daleyd Member

    Messages:
    7,101
    Location:
    Wrexham, North Wales
    Neutral may be used for the control circuit (if it has one), for contactors, relays,lights etc?
     
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  4. Seadog

    Seadog Forum Supporter

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    Good point. That detail clearly isn't shown.
     
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  5. daleyd

    daleyd Member

    Messages:
    7,101
    Location:
    Wrexham, North Wales
    Yeah, just a guess as to why it might be there - it may not have any of those things, but of course you are right it won't be needed for the motor itself if it's 3 phase variety.
     
  6. Agroshield Member

    Messages:
    1,371
    To the OP:

    That is the bit just below the middle 2.0mm2 in the diagram Seadog posted. You could easily replace that with a manual 3-pole isolator.

    Have you opened the plug to confirm that all five pins are in use? Sometimes people put on a 5-pin plug because that is the only socket they have rather than because it is actually needed.

    If the neutral wire is present and in use, what does it connect to at the machine end of the cable?

    If you are to use it on a static converter, it may be prudent to disconnect the LV transformer (top RHS of the Seadog map). Just pull the fuses F3 & F4.
     
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  7. Seadog

    Seadog Forum Supporter

    Messages:
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    Location:
    NE London - UK
    Having a closer look, it would appear that the contactor runs from the LV circuit. Pulling the fuses will remove the E-stop function from what I can see.
     
    daleyd likes this.
  8. vwmark

    vwmark Member

    Messages:
    661
    Location:
    North Wales

    It does use 5 wires.

    I will follow circuit tonight.

    Thanks
     
  9. Matrixx

    Matrixx Member

    Messages:
    463
    Location:
    North Duffield
    Don't remove the control circuit, or put a manual isolator the replace K1 , it is the there for control and safety, not having an E-stop is dangerous, also with a manual switch , if there was a power cut the motor could unexpectedly start up again when the power came back!
     
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