Wiring a MIG welder socket

  1. Logic0101 New Member

    Messages:
    5
    Location:
    Cork, Ireland
    Hi everyone.

    I have a 250 amp welder and want to hook it up to a domestic supply. There's a 32amp breaker and also higher for the shower (63amp?).

    What is the best way to wire this so it can plug into a 3 pin outlet in the house without doing any permanent wiring changes to the house?

    I know this is a huge ask for a domestic supply, if needs be I just won't run it near full power for now but I'd like to know if it's possible to get near the 250amps welding without involving an electrician.
     
  2. Adam Marshall Member

    Messages:
    401
    Location:
    Nottinghamshire England
    Hi I had a dedicated 32amp c curve mcb put in my fuse board and if you have space on your board it might be an idea to do the same. It stops the annoying trips that sometime happen with the b breakers. In my workshop I had all my fuses changed to d type breakers but I have been none to trip the breaker way back to the substation on the site when I'm plugged into the 63amp socket.
     
    Craig-SM and metalmelt like this.
  3. bigegg

    bigegg I don't drink, but I still think I know things.

    Messages:
    8,037
    Location:
    Leeds, West Yorkshire
    You could put a three pin 13A plug on it, and plug it in: that will get you 130A, maybe more from your welder.

    Ideally, you need to add a new (probably 32A) breaker to your fuseboard, then run 6mm cable from that to a dedicated 32A blue commando socket.
    you might get away with lower spec. (20A breaker, 16A socket)

    BUT:
    You should ask a qualified electrician, who will come and look at your situation.

    100A will melt 6mm of mild steel in less than a second: imagine what it could do to your house.
     
    barking mat, James1979 and metalmelt like this.
  4. Logic0101 New Member

    Messages:
    5
    Location:
    Cork, Ireland
    Thanks for the info Adam and bigegg. I think I'm going to have to hire an electrician here. Would a 32A breaker with C curve be enough for the 250amp fairly consistently without tripping?

    How is the 32A calculated on the circuit breaker to run 250A on the welder?
     
  5. bigegg

    bigegg I don't drink, but I still think I know things.

    Messages:
    8,037
    Location:
    Leeds, West Yorkshire
    There should be a plate on the welder which tells you the required input current required.

    The welder is basically a transformer: it decreases the voltage, and increases the amps proportionately.

    As to the 32A, that is the biggest current you are going to be able to get out of an unpluggable, single phase (domestic) supply.

    Any bigger, and you are lookng at a hardwired supply, or 3-phase (industrial)
     
  6. Logic0101 New Member

    Messages:
    5
    Location:
    Cork, Ireland
    OK thanks for the explanation. I do have a 32A breaker but not an industrial blue outlet which I guess is the other issue here, even if my breaker can take it, the current would be too much to pass through a domestic outlet?

    I take it this is where the electrician comes in and at the very least, gives me an outlet coming off the main switchboard, but more than likely one of those c curve mcbs as well that is tied to it if I understand correctly.
     
  7. bigegg

    bigegg I don't drink, but I still think I know things.

    Messages:
    8,037
    Location:
    Leeds, West Yorkshire
    The breaker may well be 32A, but the cable will only be 2.5mm t+e doubled into a ring (if same as UK).
    Regs say you cant put anything more than 13A sockets on that size cable. (To cut a long story short).
     
    brightspark likes this.
  8. Adam Marshall Member

    Messages:
    401
    Location:
    Nottinghamshire England
    Yes get a c32 mcb put in your board and the correct size cable to a 32amp commando socket and your mig will work great im sure . In the workshop im in now there were three 4 pin 32amp 3phase sockets but in the fuse board they had them hooked upto a c10 breaker haha. That has all been ripped out now but you can't beat having dedicated sockets for welders so they can run to full capability. In saying that I also had another workshop which only had 13amp sockets but the workshop next door had 3 phase, I asked the landlord if I could get 3 phase in my workshop but no he wouldn't have it. So I had a 250amp mig that was running off a 13amp supply and trying to do orders for customers so take it from me get a dedicated supply.
     
    bigegg likes this.
  9. Agroshield Member

    Messages:
    1,390
    All the advice is good. One thing not mentioned that will be a factor in the success of your venture is the distance from the fuse board to the socket. If the cable has to go a long distance, voltage drop can be an issue, so a bigger cable needs to be specified.
     
Advertisements