Go to your main panel and see if there is a 240 or 120 breaker controlling that sub-panel. If you have a 240 breaker, you then want to be concerned about the wire size, if it will take the load of the welder.I need a 240v plug installed in my garage. I do not have a panel in my garage. I only have a box on the outside away from my specific garage, it’s a trio garage. Would this be possible or am I out of luck? View attachment 673453 Theoutlet is for a welder. An Everlast powertig 255ext.