Wiring a Plug: Replacing a Plug and Rewiring Electronics Wire plugs correctly to maintain polarity (and safety!), that is, the correct path for the voltage-carrying hot wire and the neutral wire. Wiring a new plug isn’t difficult, but it’s important to get the hot and neutral wires connected to the proper prongs. The danger isn’t fire. The worry isAuthor: The Family Handyman How to Wire a 30 Amp Plug | eHow How to Wire a 30 Amp Plug; Slide the black and red wires from the cable into the hot terminals of the 30-amp plug. Slide the white wire into the neutral terminal, and the ground (bare copper) wire into the grounding terminal. Tighten each screw to secure the wires in place.