This page contains wiring diagrams for a ground fault circuit interrupter (gfci) with a built in switch. This device can be used to protect a garbage disposal and provide a gfci protected receptacle in a single gang outlet box. The switch can be included in the protected circuit or it can be used to control an unprotected light or other fixture.
The white wire is wrapped with black tape to identify it as hot. The black wire connects the fan to the speed controller. The red wire connects the light to the dimmer.
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.
In this diagram, two receptacle outlets are wired in the same box with a separate 120 volt source feeding each. Three-wire cable runs into the box. The black and red wires are hot and each is connected to one of the receptacles. The white, neutral wire is splice to each outlet so they share the return path. This is appropriate for standard duplex receptacles, but should not be used for GFCI receptacles. GFCI’s must have dedicated neutral connections to work properly.