Phase Question

Discussion in 'General Electronics Chat' started by Dan Pro, Sep 14, 2007.

  1. Dan Pro

    Thread Starter New Member

    Sep 14, 2007
    6
    0
    I just purchased a:
    Hobart TR-300 AC/DC Welding Machine Model TR4-300

    The info. plate on the front of the machine describes it as a 1 phase.
    The wiring diagram inside has instructions for changing the wiring for assorted input voltages
    volts: 208/230/460/575 these are 3 phase voltages.
    There are only 2 hot line input connections and a ground.
    What is this all about.
    I only have single phase electrical and am beginning to worry.
    Do I wire for 230 and run it with 240 single phase or am I euchred.
     
  2. cumesoftware

    Senior Member

    Apr 27, 2007
    1,330
    10
    Assuming that there are two "hot" input connections and an earth ground it should be a single phase device. One of the input connections is the phase and the other one is the neutral.
    Moreover, I never saw a triphase welding machine before.

    Just to confirm what I said, describe me the plug?
     
  3. mrmeval

    Distinguished Member

    Jun 30, 2006
    833
    2
    Contact the manufacturer and ask them. If you don't have the original manuals see if you can download them.
     
  4. Dan Pro

    Thread Starter New Member

    Sep 14, 2007
    6
    0
    cumesoftware

    The plug and wire were cut off.
    Inside the unit the two hot contacts were one red and one black wire and the ground terminal had the white and bare copper attached to them.

    I just checked the large plug that used to be attached and it was a three phase service.

    but the machine does have a plate attached that says 1 phase.

    The odd thing is the listed voltages are 3 phase
     
  5. Dan Pro

    Thread Starter New Member

    Sep 14, 2007
    6
    0
    I meant to say the plug wire was cut off.
     
  6. Dan Pro

    Thread Starter New Member

    Sep 14, 2007
    6
    0
    I checked Hobarts site and its to old for a download manual
     
  7. cumesoftware

    Senior Member

    Apr 27, 2007
    1,330
    10
    To be a triphase station it should have three wires and a ground, which is strange, since it has only two plus the ground.
     
  8. recca02

    Senior Member

    Apr 2, 2007
    1,211
    0
    it might not be possible to help for us without actually having to deal with the m/c in reality but,
    my opinion is if m/c ratings specify single phase it shud be one.
    also are u from US.
    a lot depends on country in terms of wiring like (2 hot and a earth or one live,neutral and earth).
    also it may be possible for a three pin plug to be designed for three phase load(not sure) and i havent come across a single phase m/c which takes in 3 phase supply.

    and an important advice get some help fro an electrician.
     
  9. Dan Pro

    Thread Starter New Member

    Sep 14, 2007
    6
    0
    From Canada
    2 live and return earth
    The plug was plated as 3 phase.
    It was worth $300 and was not included the wire was cut of at the machine.
    The machine is plated 1 phase.
    I am going to rewire from 575 down to 230 and see how it goes.

    Thanks for the advice
     
  10. subtech

    Senior Member

    Nov 21, 2006
    123
    4
    Dan, the voltages you listed are not necessarily 3 phase only voltages.
    Considering the way you have described the nameplate on your machine, you only need a single phase connection, and you have your choice of voltages that can serve the welder. The voltage tap that you choose on the welder will depend on the voltage that is available at your place of operation.
    If you are at home and you have a typical residential service for Canada, you most likely have 230-240volts single phase available. Choose the 230 tap/connection on your welding machine and proceed accordingly. The Red and Black insulated conductors will be the hot legs, and the White insulated conductor should be the neutral/return. Do not neglect the fourth conductor which should be connected to the frame of the welding machine and an earth ground for your safety. Don't forget to size your fuses/breakers and any wiring according to applicable codes for your area. If you are not sure of wire size and the necessary protective devices, check with an electrical distributor in your area. They should have experienced people who can help you choose the correct parts. If you have a three phase service available, post back with the details of the service, and I'll try to help you from that point.
     
  11. Dan Pro

    Thread Starter New Member

    Sep 14, 2007
    6
    0
    230 worked great thanks to all for the advice.
    Now if I can learn to weld better all will be great.
    Practice makes perfect.
     
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