Ground Fault protection for welders

[mopowr steve]

Personally, I think any GFCI will instantly trip the moment anyone draws an arc with a 90 amp welder.

Hopefully I'm wrong, because that will just put someone between a rock and a hard place.

The arc is on the secondary side of a welder transformer ( in which case is not connected to the GFCI ). Now if the primary side of the welder transformer develops a shorted winding to case that would be a different story.