Electric towers
Often unnoticed by most people in their everyday lives, electricity towers play a key role in providing electricity to homes and businesses. Ensuring the safety and reliability of electricity supplies requires maintaining appropriate standards of power poles, specified in the regulations and standards in force in Poland. These documents cover a wide range of issues, from construction and materials to user safety. This topic is worth taking a closer look at.
Adaptation to the requirements of the changing market
The energy industry is subject to dynamic changes. Therefore, designers and manufacturers of network infrastructure components must adapt their products to the increasing requirements and expectations of recipients. Detailed features of the structures being built are important, including strength parameters. Poles must meet technical standards, established norms and regulations, as well as take into account ecological and economic issues when delivering electricity.
Reducing the impact on the natural environment
Numerous scientific studies have found no impact of the electromagnetic field from power lines on human health or the natural environment. However, when erecting overhead lines, as with any construction, some negative impact on the environment may be noted. For this reason, the planning process is based on solutions ensuring minimization of the impact on the surroundings and meeting all environmental requirements.
Types of electric poles
Transmission and distribution power lines use various types of support structures. The basic types are strong and through poles. In the case of very long spans, crossing poles are used, while end poles are used to transfer loads from wires suspended only on one side. Their subtype are cable poles, on which the transition from overhead line wires to cable lines takes place thanks to equipment such as cable heads. If there is a need to branch the tracks, branch poles are also used. One pole can combine many functions, e.g. a branch pole is most often also a strong pole, and for example, for one direction of branching it can also be an end pole.
Requirements for electric towers
Classification of overhead power line poles
The types of power poles also depend on the voltage level of the overhead power lines. In this respect, we can distinguish LV (low voltage), MV (medium voltage), HV (high and highest voltage) poles. Solutions of various heights and mechanical strength are used. Various manufacturing and assembly technologies enable the selection of structures and foundations to suit local terrain conditions and situations. There are steel grid, tubular steel, composite and concrete electricity poles and towers.
Compliance with European Standards and regulations
Currently designed overhead power line support structures should meet the requirements of the PN‑EN 50341-1:2013-03 standard together with a dedicated national annex - currently PN‑EN 50341-2-22:2022-06. These are European Standards that define the requirements for newly constructed AC overhead lines above 1 kV. Their scope covers related construction and electrical issues. Moreover, overhead power lines as construction objects meet the requirements specified in the Construction Law together with the relevant implementing regulations.
Route of the power line and organization of the construction site
The indicated standards and regulations also include requirements and specifications regarding the route of power lines and the development of the construction site. Power lines are designed and constructed in such a way that their subsequent operation will not cause difficulties for both road and pedestrian traffic. Transmission lines do not cause difficulties in maintaining the proper condition of roads and are designed in accordance with the conditions specified by road managers in the issued arrangements.
Minimum distances from buildings
When designing overhead power lines, certain minimum distances from buildings are respected. The parameters depend on the rated voltage of the power line, the type and material of the building. In addition, the requirements regarding the maximum values of the electric and magnetic field in the vicinity of the power line must be met. The levels of electromagnetic interactions permitted by Polish law are among the lowest in the world.
Crossing power lines
Other issues concern crossing power lines with buildings where people often stay. New power lines with a rated voltage of 220 kV and 400 kV cannot cross residential and public buildings, such as schools, offices or hospitals, which usually house large groups of people. Power lines cannot also cross gas and liquid fuel stations, as well as buildings containing hazardous materials and explosion hazard zones. The distance of the pole outline from the gas station explosion hazard zone should be at least 30 meters.
Power pole standards
The construction of power poles depends on the applicable standards, as well as the location of the designed power lines and the nature of the area. Loads affecting the strength of poles of specific dimensions should be taken into account, especially the behaviour of wires and structures under the influence of external influences such as temperature changes, icing (soot) or wind, as well as combinations of these factors. By taking into account extreme meteorological conditions and other external impacts that may occur during the operation of the power line already at the design stage, Eltel Networks guarantee safe operation and effective supply of energy to private and commercial customers.