Cables and wires
The task of cables and wires, regardless of their structure or cross-section, is to provide electricity, control pulses or information. These utilities are an indispensable element of every network and installation, both in the power industry and ICT.
Cables and wires in teleinformatics and power engineering
The basic building block of cables and wires is a conductor capable of the orderly movement of electrons - most often copper, which is the basis for power utilities (although aluminum is also often used here) and ICT. Another type of cable is the optical fiber used for information transmission.
Solutions for ICT
ICT cables and wires belong to one of the three media groups available on the market for signal transmission: coaxial cables, twisted pair cables or optical fibers. In new networks, coaxial cables are practically no longer used, and the ICT network architecture is based on structured cabling in the form of optical fibers and twisted-pair cables.
A coaxial cable rarely used in ICT
Coaxial cable consists of a copper core in plastic insulation, surrounded by a copper shield. The whole thing is inside a plastic outer t-shirt. The specific structure of the concentrator allows it to be used directly at metal objects. The transmission takes place without power loss or external electromagnetic interference of the transmitted signal.
Currently, coaxial cables in ICT have almost completely replaced optical fibers. Concentrator is used in measuring techniques and as an antenna cable.
Copper, twisted pair, shielded and unshielded
Twisted pair is a signal cable used in ICT installations. It is made of eight wires twisted in pairs, where the twist in a pair is usually one coil by 6-10 cm. The twist is different for each pair of cables, which reduces the effects of mutual electromagnetic interference and crosstalk. The cable is also protected against interference from the environment.
There are different braiding technologies and therefore individual twisted pairs may have different twist. The signal cable is most often used in telephone installations and Ethernet networks, with the FTP (unshielded) twisted pair being more popular than the UTP (shielded) twisted pair.
Categories of structured cabling
The division of structured cabling into categories is a way to organize the elements of the ICT system, as well as to ensure backward compatibility with older solutions. The following categories can be distinguished: 1, 2, 3, 5 / 5e, 6, 6A, 7 and 7A. Currently, the category 5 (less and less) and 6 twisted pair are commonly used, while the higher categories are used in the construction of specialized computer networks, e.g. backbone.
Fiber optic cable
Both coaxial cable and twisted pair, together with power cables and cables, belong to a wide group of electrically conductive media. Transmission consists in conducting electrical impulses, while in an optical fiber the signal carrier is a beam of infrared light, which is transmitted through the glass fibers.
Compared to copper media, optical fiber is characterized by much higher capacity, insensitivity to electromagnetic interference and long-distance transmission. However, it is fragile and delicate, and requires expensive network equipment, so it is not used as often as it could due to the quality of the transmission.
Solutions for the power industry
The power industry is primarily cables and copper and aluminum wires, which can be divided into bare and insulated. Bare cables are used in overhead lines, while insulated cables and cables are laid in the ground, under plaster, in plaster and on plaster.
Cable and wire markings
Cables and wires in the power industry are marked in a certain standardized way in order to facilitate identification by installers, and thus ensure the safety of the installation. Markings are placed on the cable insulation in the form of a clear imprint. The first letter of the designation determines the structure of the vein:
D - wire;
L - line;
Lg - flexible line.
When the conductor is made of a material other than copper, the letter A (aluminum) or F (steel) appears before the conductor structure designation. Before marking the material, in turn, the term of the cable sheath may appear, i.e. the letter Y (PVC sheath).
Letters describing the insulation material appear after the letter (s) denoting the core structure:
Y - PVC;
G - rubber;
X - polyethylene.
The next letter refers to the construction of the cable (e.g. d - increased insulation thickness, p - flat cable), and the next letters help to define its purpose (e.g. ak - battery cable, t - plug-in cable). In addition to letter symbols, it is also used on wires designation of the rated voltage.