Prong - su Amazon AdRisparmi su Prong. CD, Vinili & molto altro How to Wire a 4-Prong 240-Volt Twist-Lock Plug | Hunker How to Wire a 4-Prong 240-Volt Twist-Lock Plug outside, every four-prong, 240-volt plug has the same 220 volts in the world of residential wiring. 220 Volt, 4 Prong Plug Wiring by Jaden - Alpha Rubicon *220 Volt, 4 Prong Plug Wiring* By: Jaden 10 April 2008. Some 220 volts AC plugs have 4 prongs. This simply means there are two hot wires, one neutral and one ground.