Understanding 120/240V Wiring Color Code | DoItYourself They may, however, be capable of working with either type of wiring. If you are replacing an older cooking appliance or dryer, the instructions may tell you that you can, by replacing the cord on the appliance, connect it to an existing three-wire 240V circuit. There are still 240V appliances that only need two hot wires and a ground.Author: DIY Staff How to Wire a 240V AC Outlet - instructables How to Wire a 240V AC Outlet: We were given a welder that has a big 240 volt plug, but our home doesn't have any 240V outlets already wired. What to do? Wire your own! Turns out the plug we had is NEMA 6-50. You can probably figure out what yours is from a chart. If it's clo..