Be advised, the welder will NEVER pull what it says it will. They are
highly overrated. Besides a #8 would be fine for 40A. 10ga on a 30a
breaker will work fine.

Steve Barker


wrote in message
...
To connect a welder about 15 feet from breaker box. The welder says
primary amps 40. A wire chart on a website shows #6 as 37.5 amps.
Will #6 be close enough or should I use #4? I know the welder will
not be drawing full amperage most of the time, only on spikes.

Thanks