240 40 amp is going to require 2 20 amp 110v breakers. You can buy 220/240v breakers that are really nothing more than a tied pair of 20 amp 110v breakers.
My miller mig is wired the same way.
Be very careful. 220 can easily kill you.
Last edited by Michigan Larry; 02/26/14 11:49 AM.
1968 Firebird 428 4 speed coupe

2011 Camaro 1LT
1988 Corvette roadster
1975 Chevelle Malibu Classic
1984 Harley FLH Shovelhead
2001 Harley Ultra Classic