A dedicated circuit has only one device, usually a receptacle and supplies power to one load only. This type of circuit is normally used for high wattage appliances.
Dedicated Circuit Wiring
In the diagram below, a 3-wire NM cable supplies line voltage from the electrical panel to the first receptacle outlet box. The red wire (line “B” phase) connects to the first receptacle only. The black wire (line “A”phase) connects to the black wire of an NM cable that travels to the next receptacle box. The white (neutral) wire connects to the first receptacle and the 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.