Wiring Diagrams for Electrical Receptacle Outlets - Do-it Wiring a 20-Amp 240-Volt Appliance Receptacle. This outlet is commonly used for a heavy load such as a large air conditioner. The outlet should be wired to a dedicated 20-amp/240-volt circuit breaker in the service panel using 12|2 awg cable. With this wiring, both the black and white wires are used to carry 120 volts each and the white wire is wrapped with electrical tape to label it hot. How to wire a plug - Easy Do It Yourself Home Improvements If you are wondering how to wire a plug, you have come to the right place. Wiring a plug is perfect for the beginner do it yourself-er. After you master this project, you can add some split receptacles to your kitchen. But first, let's get to wiring a plug..