Wiring Diagrams for Multiple Receptacle Outlets - Do-it Wiring for multiple ground fault circuit interrupters (gfci) and standard duplex receptacles are included with protected and non-protected arrangements. Wiring Multiple Outlets in a Series In this diagram wall outlets are wired in a row using the terminal screws to pass voltage from one receptacle to the next. Wiring Diagrams for Electrical Receptacle Outlets - Do-it Wiring a Grounded Duplex Receptacle Outlet. This is a standard 15 amp, 120 volt wall receptacle outlet wiring diagram. This is a polarized device. The long slot on the left is the neutral contact and the short slot is the hot contact. A grounded contact at the bottom, center is crescent shaped. Don't use this receptacle when no ground wire is available.