In the diagram below, a 2-wire NM cable supplies 120 volts from the electrical panel to the first receptacle outlet box. The black wire (120 volts) and white (neutral) connect to the receptacle terminals and another 2 wire NM that travels to the next receptacle. This repeats until the end of the chain.
Diagrams shown on this page are simplified for clarity. Electrical outlet boxes can have numerous NM cables going in and out. See Actual Switch Box Wiring Diagram.
Typical NM Ground Wire Connections Diagram is shown below.
Dryer Receptacle Wiring
In the to the right, a 3-wire 10 AWG NM cable supplies 240 volts from the electrical panel to the dryer receptacle outlet box. The black wire (120 volts “A” phase) and the red wire (120 volts “B” phase) supply the 240 volts. The white wire supplies neutral to the dryer receptacle.
The ground connect ion is shown in this diagram.
Receptacle Wiring Diagram
Dryer Receptacle Wiring Diagram
Typical Ground Wire Connections for Receptacles
All ground wires and device terminals are connected together in each outlet box.
In each electrical box, all ground wires are connected together. Ground is also connected to the ground terminal of a device (switch, receptacle, light fixture, etc).
Typical Ground Wire Connections Diagram for Receptacles