How to Wire a 30-Amp Twist Lock Plug | Hunker How to Wire a 30-Amp Twist Lock Plug How to Connect Wires to a 3-Wire Plug 3 How to Wire Romex to a Plug 5 How to Wire an Electrical Three-Prong Plug 6 How to Wire a NEMA L14-30 Plug Subscribe for weekly inspiration. Subscribe. We respect your privacy. How to Wire a 30-amp RV Plug | It Still Runs The 30-amp RV plug is colloquially known as an RV-30. It has two angled flat blades, and one U-shaped pin. Wiring a 30-amp RV plug to a preexisting umbilical from the RV is a simple matter, and can be accomplished with normal household electrical tools.