I'm helping a friend work out the details for a new shop he is building. He
has an older 275 amp tig welder, probably a Lincoln, at least 15 - 20 years
old. Power input is the question, it's on 240 volt single phase. The
electrician has rough-wired a 40 amp service, which I strongly suspect will
not be sufficient. I don't have a specific model to research, but looking
at similar size welders I see input current spec'd at about 100 amps, which
may not be available - total to the shop is 100 amps. I suggested at least
60 amps and just don't turn up the current past about 150 or so, which won't
be a problem - he works with thinner steel (.125" or less), and very little
aluminium.

So, can we use a 60 amp circuit for this welder and use discretion on the current dial, or is there a surge requirement in starting the arc, etc, that I'm not aware of? Is 60 amps enough to run a welder like this at 150 amps with about a reasonable duty cycle (my Square Wave 175 is on a 60 amp circuit). What other options are there bar getting a new welder?

Thanks very much, Brian

So, can we use a 60 amp circuit for this welder and use discretion on the current dial, or is there a surge requirement in starting the arc, etc, that I'm not aware of? Is 60 amps enough to run a welder like this at 150 amps with about a reasonable duty cycle (my Square Wave 175 is on a 60 amp circuit). What other options are there bar getting a new welder?

Thanks very much, Brian