In this diagram wall outlets are wired in a row using the terminal screws to pass voltage from one receptacle to the next. In this diagram, multiple receptacles are connected together using the device, instead of a pigtail splice as shown in the next diagram. Using this method, any break or malfunction at one outlet will likely cause all outlets that follow to fail as well.
In this diagram multiple ground fault circuit interrupter receptacles are wired together using pigtails. Two-conductor cable is run between gfci’s, and the hot, neutral and ground wires from the source are spliced to the line terminals at each device. The load terminals are not used and each device provides its own, single-location protection.
This wiring diagram illustrates the connections for dual controls, a speed controller for the fan and a dimmer for the lights. The source is at the controllers and the input of each is spliced to the black source wire with a pigtail. From the controllers, 3-wire cable runs to the ceiling outlet box.
Here 3-wire cable is run from a double-pole circuit breaker and split to supply 120 volts to two sets of receptacles. The neutral wire from the circuit is shared by both. This wiring is commonly used in a 20amp kitchen circuit where two appliance feeds are needed, such as for a refrigerator and a microwave in the same location.