Things You'll Need
Clothes dryers, electric ranges and other major appliances all require 250-volt plugs in order to function. Most of these plugs come already attached to the end of the cable that attaches to the appliance. Sometimes when a pre-formed plug and wire are not available, it becomes necessary to attach a plug to the wire from the appliance. These plugs accept three or four wires depending on the type of appliance being attached to it. The good news is that since this is a plug and not a socket, you do not have to worry about electric shock while doing the wiring.
Remove the screw in the center of the 250-volt plug. Pull the front of the plug forward and away from the back of the unit. Inside the back of the unit you will see three lugs with screws. There will be another screw near the bottom of the plug that is usually green.
Strip two inches of the outside insulation from the 250-volt wire to expose the three or four inside wires. Strip one inch of the coating from each of the inside wires. Pull the red and black wires away from the bundle and bend them with your fingers so the ends are lined up with the outside lugs on the 250-volt plug.
Slide the ends of the red and black wires under the screws. It does not matter which color goes to which side. Slide the end of the white or bare wire under the screw in the upper end of the plug. If there is a green wire, bend the end of the wire into a hook with needle-nose pliers and hook it around the green screw.
Tighten all of the screws to secure them to the plug. Replace the front of the plug onto the back panel. Insert the screw and tighten it to fasten the front of the plug onto the unit. Follow the manufacturer's instructions and attach the other end of the wire to the appliance being installed.
Always make sure you purchase the type of 250-volt plug that matches the outlet it will plug into.
Make sure the 250-volt wire you are using is rated to handle the load for the appliance that the new plug will serve.