George,
I did this 25 years ago in a saw mill. It's been a long time but if I remember correctly we used 250 MCM type THHN copper conductor. We ran the hot lead only, the building steel was used for ground return to the welder. The hot conductors ran to several J-boxs around the mill where they were spliced to a short piece of welding cable with a female welding type connector on it. This short piece was attached to the box with a kellums type grip. The stinger could then be connected to any of these "hot boxes".
There were two or three welders installed this way. Each one served a different area of the buiding.
We also installed an illuminated push button at each "hot box" location. These push buttons were wired to a contactor that turned the welder itself on and off.
The state electrical inspector passed it and the system is still in use today.
[This message has been edited by Helectric (edited 12-27-2005).]
