Normal 20 Amp Receptacle Wiring | DataBase Of Wiring Library Normal 20 Amp Receptacle Wiring - Product Description. The Hubbell USB20X2W is a 20A, 125V, 2 Pole, 3 Wire Grounding USB Charger Receptacle. It has two USB ports that are 3.8 Amp, 5V, type A and Class 2.0. 20-Amp SmartlockPro Self-Test GFCI Testing a GFCI is a good way to verify that it is providing protection. Wiring Diagrams for Electrical Receptacle Outlets - Do-it Wiring Diagram for a 20-Amp 120-Volt Duplex Receptacle A 20 amp, 120v duplex receptacle outlet like this should be installed in a circuit using 12 awg cable and a 20 amp circuit breaker. These receptacles are usually found in kitchen wall outlets where two branch circuits are needed to serve small appliances and a refrigerator separately.