Formally, the cable – this is the device used for drainage of electricity (and pulses) and consisting of a divided one (or more) conductors, enclosed in a protective layer of rubber, plastic, aluminum or lead. Cables, connectors and integrated terminations form a cable line. Widespread has a cable design, which consists of conductors, conducting electricity, insulation layer and the outer layer with protective covers. Once upon a cable consists of one or more wire conductors with various forms of cross-sections ("circle", "sector", seglyantnaya form) By type of insulation layer and an outer layer is divided into four main types of power cables: a) a metal outer layer and impregnated with special substances paper insulation component; b) with a metal outer layer and impregnated with the composition does not flow paper insulating component; c) a metal or plastic outer layer and an insulating plastic component; d) with a plastic, rubber or metal outer layer and an insulating rubber component. Control cables are designed to build chains of control, signaling, etc., for fixed connections to the electrical appliances and devices. Cabling can be run: in all kinds of special designs, and plants (in production facilities, tunnels, trays, etc.); on the walls of buildings and premises in the trenches and blocks (across the enterprise or larger areas). Choosing the scope of the specific type of power cable to the conditions of installation and operation is carried out by etu (Uniform technical guidance on the selection and use of electric cables.) Often, it is recommended to use the cable etu with aluminum and plastic shells *.

Complexity (variety) of cable routing determines the impact on the cable required when laying. By the complex include: Cable route for laying in the ground one building cable length more than 4 turns at an angle 30 Straight cable runs – more than 4 passages in the pipes longer than twenty feet, or more than two transitions in the pipes longer than forty meters. Laying of cables in tunnels more than two changes of direction with the length of the pipe for more than twenty feet, as well as 4 (and more) pass in fire-resistant partitions, in addition to the leads for electrical cables Lots of cable lines, not included listed, are simple. In the sections of cable lines, related to the complex in order to prevent damage or destruction of PVC cable is not recommended to use cables and cables with AAShv odnoprovodnikovymi veins cross-3h24 3×15 cm2. At higher tensile loads ** recommend the use of cables, armored steel wire. When laying in buildings with temperatures above 50 C and below maximum allowable for a long cable will probably use standard cables, but in this case need to reduce shock loads or reducing the time of use. In the event that the cable will exposed to vibration, it is necessary to use cables with an aluminum or plastic outer layer. Data by choosing the type of power cables for the specific conditions listed in Table.

1, 2, controls – Standard in 1508.78 Table 1. Cables are recommended for installation in the ground Table 2. Cables are recommended for installation in air. * Power cables with a protective layer of lead used in subsea lines, dusty, corrosive and highly dangerous conditions, and etc. ** Higher tensile loads are called forces that appear during the lifetime of cables laid in loose, muddy, heaving and permafrost soils, water, and in areas with similar characteristics.