Basic concepts of electrical wiring involve creating circuits that provide electrical power for equipment and devices. The majority of residential wiring utilizes single-phased power to provide varying levels of voltage to outlets and appliances. Plastic boxes and flexible non-metallic cables are common in a variety of wiring projects.
The most basic rule of electrical wiring is to disconnect power before working with wires, outlets or fixtures. Shutting power off at the breaker and using a non-conducting voltage tester are common practices when wiring. Use of a lockout tag provides an additional level of safety when working with electrical wiring. Local building and construction codes exist to ensure electrical wiring does not cause a fire or safety hazard.
Single-phased power systems use two live wires and one neutral wire to supply power to appliances and outlets. Wiring a negative wire and a single live wire produces lower voltage that is suitable for the majority of outlets and fixtures. Wiring both live wires produces the higher voltage levels needed to operate major home appliances. Circuits used in residential wiring pass through the main service panel or breaker. This service panel provides an easy and effective way to break the circuit and operates much like a light switch.