Kojunho, Just curious of the model of the Miller Tig. I would like to read the manual. I looked at a couple of Maxstar models on the website. The manuals seem to be on the money with ground and sizing recommendations. It seems like like the sizing recommendation in your post is based on motor sizing rules. I have hooked up welders and used to clean the Miller hard-wired welders at my last shop. Really wierd, but with todays technology anything is possible.