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.
Types 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.
Using electrical services
Electrical services enjoy unflagging popularity properly since arisen. Many people prefer to pay relatively little money for even simple electrician services, such as replacing light bulbs and electrical installation nietrudnych than yourself to start playing with shock, which may prove undoubtedly dangerous. The use of electrical services is also popular for the modernization of the electrical and other more complex services, as to carry out such orders, especially in the case of larger objects, very often you need to have the appropriate permissions, you can have only trained electrician.