diagram for 110/220 pigtail here

[vault]

sooo I guess it does not matter which wire is hot for 120V input? since both AC input wires go to the welder's switch, I guess that is all that matters...?

I don't know if it will effect the welder. But why not just wire it according to convention hot black wire to narrow slot and gold screw on the receptacle then the neutral white wire to the wider slot silver screw on the receptacle then you know for sure you won't have a problem and if you plug anything else in to the receptacle that the polatiy matters you don't have to worry about it?

[robrob]

But why not just wire it according to convention hot black wire to narrow slot...

Henry is talking about the welder's wires, not the wall outlet or pigtail. You should follow convention as you describe, but the tough part of this is figuring out which welder power cord wire gets the single 110v hot wire.

If your welder's power cord has standard black, white, and green wires then I'd wire the black wire to the narrow blade and the white to the wide and make sure the pigtail is wired the same. But check your welder's wiring manual or operator manual to be sure.

As I said earlier, at least one dual-voltage welder I read about had a yellow power cord wire that was supposed to get the 110v hot (black) wire for 110v operation.

[weldingtwopotatoes]

I got my 220 to 110 pigtail done, just wanted to say that I appreciate everyone posting the info on the board, it came in handy.

[ksmeggy]

Henry is talking about the welder's wires, not the wall outlet or pigtail. You should follow convention as you describe, but the tough part of this is figuring out which welder power cord wire gets the single 110v hot wire.

If your welder's power cord has standard black, white, and green wires then I'd wire the black wire to the narrow blade and the white to the wide and make sure the pigtail is wired the same. But check your welder's wiring manual or operator manual to be sure.

As I said earlier, at least one dual-voltage welder I read about had a yellow power cord wire that was supposed to get the 110v hot (black) wire for 110v operation.

It almost certainly doesn't matter. I'm not going to re-open the machine to check, but yes both wires go through the switch and go to the same PWM circuit to convert to DC.

[vault]

Henry is talking about the welder's wires, not the wall outlet or pigtail. You should follow convention as you describe, but the tough part of this is figuring out which welder power cord wire gets the single 110v hot wire.

If your welder's power cord has standard black, white, and green wires then I'd wire the black wire to the narrow blade and the white to the wide and make sure the pigtail is wired the same. But check your welder's wiring manual or operator manual to be sure.

As I said earlier, at least one dual-voltage welder I read about had a yellow power cord wire that was supposed to get the 110v hot (black) wire for 110v operation.

sorry, my bad

[weldingtwopotatoes]

Here's a picture of my finished pigtail.

[vault]

very nice and clean looking