Household electricians please respond for Bronco help

[Skuzzlebutt]

I need to do some welding on the Bronco today. My problem is that I've just moved to a new house, and every time I move I need to change the plug (240v) on my welders power cord. I've done this enough times for it to be a no brainer, or so I thought.
The outlet in the new house is of the 4 pronged variety, and my cord only has 3 wires. The old setup was Green = Ground, and that is still true with the new setup. The Black & White wires were the power wires, but now Black & Red are the power wires, and White is the Neutral wire. What in heck does the Neutral wire connect to? Do I splice it into the Green? Do I just ignore it?
I cannot simply change the whole power cord due the the fact that my current (PUN partially intentional) power cord is 100' long, which is very nice to have and in my current house, 60' is necessary, and 250v extention cords are bookoo (pardon my French) dollorres, and being in the middle of a double move has me on a very tight budget.
So, in brief summary, how do I splice a four wire plug into a three wire cord?
And I'd really like to have this done today. I do already have a splicing kit for four wire cords including the shrink wrap lined with glue.

TIA

 

[bax]

White is neutral and it can be left off or hooked up to the green. White is hooked in the house box to the neutral ground. This will become a 220 cord only.

I would just wire nut it off and not use it.

Bax

 

[SteveL]

As long as your welder is 240 volt use the 2 hot wires and the green ground wire. You can cap off the neutral(white). Some 240v equipment will use a neutral for eletronic controls that require 120v operation.

 

[kuch68]

It is always a good idea to double check the previous electrician's (or homeowner's) work. I was suprised my house had not burnt down after seeing the PO wiring strategies. I am not a certified electrician but have rewired my house. Here is what I would do:

1. Make sure the circuit is a dedicated circuit and locate it in the service panel.
2. Turn the main disconnect off in the service panel and removed the wire you are not going to use and check with a multi-meter that the wire is no longer common to your ground, or for some reason hot (found one in my house when the wire was disconnected.)
3. Finally, just use the black and red as your out of phase hot, and your green as your ground.

It might be overkill, but safety first.