I'm trying to determine wire size and CB size to feed a welding receptacle and am a little foggy on it. Nameplate data is 230V, 54A @40% duty. I would size the conductor as follows? 54A x 0.63 (42-006 (1))= 34A. So #8 would be required. Now the O/C protection is where i'm getting stuck. I know i'm allowed to go to 200% of rated primary current according to 42-008 (1), but is this still true if i was to use a receptacle such as a 6-50R as a disconnecting means. I have a tough time believing that we are allowed to feed a receptacle with #8 and protect it with an 80A breaker considering that something else could be plugged into it. Although 42-004 does say that, right? Also, if i wanted 2 receptacles in different locations for the same welder, would i have to use 42-006 (2) considering the same welder will never be plugged in at both locations. Thanks for any help

Edited by allanb (02/08/09 02:21 PM)