Ferrari Mailing List: [NFC] Running a single-phase welder on 3-phase power

[Peter Rychel (dino308gt4]

I wired this up last night at work and it runs fine, but want to post this and get feedback to see if I did this properly.

I work at a heavy industrial shop and all of the other TIG welding machines were being used. When our sister shop was shut down last year, we inherited their equipment and stock and I noticed an old Lincoln TIG/stick welder in the pile of junk. Last night I was in a crunch to get a TIG job done and I remembered that one, but when I pulled it out, I noticed on the panel that it was rated for 575V at SINGLE phase. Our shop uses THREE phase power.

I checked our outlets and if I measure from ground to one of the terminals, I get 300-some odd volts and if I measure from terminal to terminal, I get 600V.

From what I could gather from Google searching, if I omitted the one lead from the power cable (so, on the machine, only Green, Black and White versus the three phase cable of Green, Black, White and RED), it should work. My Miller Dynasty TIG machine I have at home is like that, you can run it on single phase power by just not connecting the forth, red lead of a three phase outlet.

I wired it up that way and it worked fine, but there were some notes that I read that it works, but is hard on the machine transformer. Is that true? Considering this is surplus equipment, it will only be used in emergency situations like this and is not going to be run during both shifts, day after day.

Peter