Power transmission towers and their installation
Infrastructure of distribution of power networks onlong distances, as a rule, provides for the organization of air networks. As transmission contours, power lines (LEPs) are selected, for which special supports are used. These are the structures on which wires and associated fittings are fixed. Depending on the conditions of use and the characteristics of the network, different types of power transmission towers can be used. In the future, the quality of the organized network will depend on the installation and technical support of the line.
General information on power transmission line supports
The support, included in the power line,performs the tasks of supporting wires and optimal tension. Each support has in its design a special fittings for fixing cable lines. In this case, the purpose of the route itself can also be different. This applies to the transmission lines of current, and communication fiber networks, as well as telephone wires. The belonging of the route to one of the above categories partly determines what technology will be used to install the power transmission line supports at a particular site. So, the higher the voltage, the more important the installation. The quality of installation will also be affected by auxiliary elements in the form of retainers and clamps. And this is not to mention the need to get enough distance from the wires to the ground and body support. Complex sections of the network require the development and preliminary calculation of the project, which will carry out the installation operations.
Types of supports according to purpose
Supports are intermediate, with an anchorsupport, angular and special. The most common intermediate structures, installed on straight sections of the lines. They perform the tasks of supporting cable paths and do not calculate for additional stress loads. Anchor structures are also mounted on straight sections, but, in addition to supporting the wires, can also absorb the load from the traction. For this reason, the anchor supports of the power lines are robust and durable. As for the angled supports, they are used in difficult areas with turns and transitions. Such structures are assigned to the load from their own lines, but the longitudinal load can also be transferred from the tension of adjacent networks. Complex configurations of bundles of trunk, transitional and branch lines provide special supports. Often they are manufactured for operation within the framework of specific projects of the power transmission line organization.
Varieties according to the material of manufacture
The most durable material for supporting structuresis reinforced concrete. These are shaped beams with a rectangular cross-section, the structure of which is provided by metal rods. The advantages of reinforced concrete support also include resistance to biological, chemical and climatic influences. Similar to reinforced concrete for some strength indicators and metal structures, but they are used less often due to weak protection from the processes of rust. The most affordable solution is wood - such models cost 1-3 thousand rubles. average. For comparison: the reinforced concrete poles of power lines on the market are available for 5-7 thousand. But wood is a short-lived element of the infrastructure and needs updating already in the first years of operation. Alternative option can make a composite column. This material, like wood, is characterized by lightness and corrosion protection, but at the same time it does not undergo biological destruction processes. However, the composite costs more than reinforced concrete.
Installation of power transmission line supports up to 1 kV
Installation is carried out in several stages, butpreparatory measures are first carried out. If necessary, the installation points should be cleared and in some cases reinforced additionally. If the installation is planned through forest zones, it is not necessary to cut down. The average distance between the power line supports is 35-40 m, and the choice of fixing points is necessary so that the trees and shrubs are 1-2 m from the pole.
Next, drilling or pit digging is performed. If it is planned to install reinforced concrete or metal supports, special equipment and mortar will be needed, which forms the foundation for the integration of the support. Special equipment drillers will prepare a pit in which the pillar will be installed. Manually digging with a depth of about 30-50 cm. This option is suitable for the wooden support of a power line or a composite analog. After fixing the pole, traverses, insulators and brackets are mounted. The fixation of the wires themselves in simple circuits is carried out by wire knots.
Features of installation of supports up to 10 kV
In this case, the supports of largesizes, having a high weight and a high level of operational responsibility. Therefore, the editing technology has its differences. In particular, for the reinforcement of the lower part of the support in the ground, the development of foundation pits is required by an excavator. The very installation of power transmission towers is not complete without pouring the foundation into a prepared niche. Particular attention is devoted to ensuring the reliability of the structure. So, in order to protect against fires and other damaging processes around the installation point, a kind of insulating trench is formed. The radius is usually of the order of 1-2 m. What is even more important: the grounding of such supports is made of rod vertical elements made of angular steel.
Conclusion
Overhead power lines in the overall structurecan perform not only the tasks of distribution and delivery of energy. Often the route acts as a communication channel for auxiliary needs. Another thing is that most of them also focus on the technical support of local infrastructure. In this context, it is of particular importance that the power transmission line supports, since not only the wires but also the additional functional fittings are attached to them. Also, the technology of the power line organization provides for the creation of maintenance points. These are responsible sites where personnel can carry out preventive measures - for example, assess the voltage level of the line, etc.