Wikipedia about wires and cables
Building wiring is the electrical wiring and associated devices such as switches, meters and light fittings used in buildings or other structures. Electrical wiring uses insulated conductors.
Wires and cables are rated by the circuit voltage, temperature and environmental conditions (moisture, sunlight, oil, chemicals) in which they can be used, and their maximum current. Wiring safety codes vary by country, and the International Electrotechnical Commission (IEC) is attempting to standardise wiring amongst member countries. Colour codes are used to distinguish line, neutral and earth (ground) wires.
Variety of electrical contractors
Electrical contractors are generally classified by three major types of work performed.
"Outside" or "line" contractors are responsible for high-voltage power transmission and distribution lines. Line contractors build and maintain the infrastructure required to transport electricity generated at a power plant through a series of high-voltage lines and substations before it is used to power facilities, buildings, and homes.
"Inside" electrical contractors provide electricity to any structure within a property?s boundary lines, including outdoor lighting or substations. Under current construction specification guidelines, "inside" electrical contractors can serve as prime contractors for all electrical and cabling design, installation, and maintenance for commercial, institutional, and residential buildings. Projects also include Database Centers/Infrastructure and Pharmaceutical Work.
"Integrated building systems" (IBS) or "Voice/Data/Video" (VDV) electrical contractors work primarily with low-voltage installations such as back-up power, climate controls, wireless networks, energy-efficient lighting, telecommunications, fiber optics, and security systems. IBS contractors are particularly skilled at integrating these system controls to work together for maximum energy efficiency and building performance.
Job opportunities in large enterprises
Large industrial plants require continuous supervision by electricians. In such places, electrical work, after-hour, including the usually public holidays and so on. Often continuity of production makes the conduct of such processes is profitable. Production plants are often places where electricity specialist can find a well-paid job. This involves a number of responsibilities for the most number of installations. Moreover, work in the industry can find a lot of people, because the large volume production is accompanied by high employment, also in the field of electrical engineering.