Glad you got it worked out, but I won't delete it. I'll leave it to help others. So many people freak and panic when they buy a welder over little things and this demonstrates what we have been saying: Most of the issues we encounter with customers are easily corrected, if not caused by the customer.

If you used any plug from the US/Canada, it wouldn't say use white for the ground, at least not in any circumstance that I am familiar with. You should be using a NEMA 6-50P, and it wouldn't say that either. But if you are using a 14-50, white would be used for the common, and green for the ground.