Electric wiring is a means by which a consumer of electric energy can operate his items of electrical equipment as and when he wishes. The wiring extends from the consumer's terminals, where it is connected to the electricity supply mains, to the various outlet points such as ceiling roses and wall sockets.
The term fixed wiring is often used to distinguish the wiring serving the fixed outlet points from flexible wiring such as that attached to appliances, familiarly known as leads.
Wiring comprises cables together with associated apparatus for control and protection. Cables consist of conductors, insulation and sometimes mechanical protection. The purpose of a conductor is to carry the current, and it is therefore constructed of a material offering little resistance to the flow of electric current, such as copper or aluminum. The conductor is generally in the form of either a single wire or of a group of wires (known as strands) in contact with each other.
The main function in insulation is stop the current from running out of the conductor in locations where it isn't needed to flow. Therefore, a material that provides a very strong resistance to the flow of current is employed to provide insulation, like polyvinyl chloride (p.v.c.) or magnesia (mineral).
Mechanical protection could be in the form of an integrated overall sheath made of an insulating material or steel or the cable might be enclosed in the form of a trucking, conduit or duct.