I just bought a Econotig which I had found for what I saw as a nice price. The guy before me was selling it for a friend and the owner had wired an extension on the the power cable. I was told the machine is in perfect working order but I went ahead and opened up the slice just to make sure. When I got inside the cable I saw that the line from the welder has three wires (White, Black and Green) and the extension has four (White, Black, Green and Red). The fourth line (Red) was left open as it had no correlating connection. This bothers me. I have never wired a 220v before and was wondering if this is a common occurrence and what should be done about it. Ideally, I would like to have this Red wire connected to something if at all possible, but I am not even sure what its purpose is.

Any help would be greatly appreciated.

-Lee