traffic loads), strains during the installation (for example, tensile strength) and the investment objective (E.g. number of cores). The number of stranded wire or wires that conduct electricity through the cable, is known under the term “Number”. In the case of multicore cables, each wire with an own insulator is provided; the individual insulators are then protected by an outer casing (wire insulation). For marking the veins isolation for two-wire cables usually the colours red for plus (+) and black for minus (-) used. However, refer to cable for AC voltage, the colors used Brown and blue, to plus and minus to highlight. Network cables protection class I, there is a green yellow protective earthing conductor, which prevents dangerous contact voltages (E.g.
on housing and control panels) in the event of a fault. Apart from that are in this type of network cable accompanied by black or brown outer conductor as well as a blue neutral conductor. It is three-phase according to old standard, two are black and used a brown outer conductor; the new standard provides the use of a gray, a Brown and a black outer conductor. The vast majority of the high-voltage cable is indeed f.t., but also bipolar high-voltage cables (DC voltage) and three-wire high voltage cable (three-phase AC) are produced. Cables that are used in the fields of signal transmission, computer and communications technology, is characterized by a number of veins from two to several thousand pieces. Distinctions are made first and foremost in the veins verse release type (E.g.
lagenverseilt, quad). The veins are the focal point of the cable, since they carry the current from A to B. So that this works, the veins are made copper usually made of precious metal, which is known for its optimal electric conductivity. There are also companies that aluminum make the wires from the light metal- and this despite the fact that aluminum has only about 2/3 of the conductivity of copper. Aluminum is so popular, because its weight only 1/3 the weight of the copper. In places where there is no lack of space and it rather depends on the weight, aluminium conductors are much more beneficial than the copper Variant. Overhead lines, which conductors are mostly made of the alloy are a popular range for aluminum. Even better properties of conductive copper and aluminium is silver. However used the precious metal for cost reasons only in some industries, such as high-frequency technology, where it is used as a coating for copper cable. Also superconductors and optical conductors such as fiber-optic cable and fibre-optic cables are also rarely-used in communications networks.