Wanted to hit the local HD this afternoon for supplies for tomorrows project. Running a 40' section of #10 wire to my attached garage from a 240V 20 amp breaker in my main panel in the basement. Yea I know I can use #12 I want to use #10. Heres my question, does code require me to use a 3 wire or 4 wire outlet? My plan was to use just a 3 wire outlet (for a welder) but may also be used later for a metal lathe. Thanks in advance. Uncrichie.