Wires for Power Transmission Lines
Wires for Power Transmission Lines
Wires for power transmission lines are used to transfer energy in the regional, distribution and internal electrical networks, as well as in electric transport lines. The choice of conductor products for a particular facility is often determined by the type of metal the wires and core are made from.
Steel wires have high mechanical strength and are optimal for routes with complex passages due to the landscape peculiarities (rivers, lakes, mountain gorges, etc.). At the same time, steel is characterized by a high specific electrical resistance, making it difficult to transfer electricity over long distances. Wires with aluminum and copper conductors are more suitable for such sections of power transmission lines.
Copper Wires for Power Transmission Lines
Made of hard-drawn wire, which has a low specific resistance of 18 ohms, but high mechanical strength. The ultimate tensile strength ranges from 36 to 40 kgf/mm2. These wires resist various atmospheric effects and metallic corrosion caused by harmful impurities in the air. Copper wires for power transmission lines are marked with an uppercase letter M and a nominal wire cross section after a dash.
Since copper is a very rare metal now, it is very rarely used in production of wires for power transmission lines.
Aluminum Wires for Power Transmission Lines
In contrast to copper wires, they have a lower weight, but high resistivity, R=28.7 ohms and a lower mechanical strength of 15.6 kgf/mm2. In most cases, aluminum wires for power transmission lines are used in local power supply networks. Due to their low mechanical strength, aluminum wires do not allow for greater traction, which results in the need to shorten the distance between power transmission lines.
To increase the strength of aluminum wires, they are manufactured using multiwire technology using hard-drawn cores. From the point of view of atmospheric effects, aluminum wires show good durability, while poorly resisting harmful impurities in the air. Due to this, a special brand of corrosion-protected aluminum wires (AKP) is used in the vicinity of seas, chemical plants, and salt lakes.
Aluminum wires for power transmission lines are marked with the capital letter A and a wire section.
Steel Wires for Power Transmission Lines
These wires have a high mechanical strength from 55 to 70 kgf/mm2. Both single-core steel wires for power transmission lines, and multi-core are manufactured. The resistivity of steel wires is much higher than that of aluminum wires, and depends on the current flowing through the wire in AC networks.
Steel wires for power transmission lines are mainly used in networks up to 10 kV, for transmission of small power, when the construction of aluminum power transmission lines is less profitable.
The main drawback of steel wires is the susceptibility to corrosion. Galvanizing, as well as copper-plating are used to reduce corrosive properties of steel.
Steel-Aluminum Wires for Power Transmission Lines
This grade of wires for power transmission lines has the same resistivity as the aluminum wires due to the fact that in calculations of resistivity the steel part conductivity is not taken into account because of its insignificance in comparison with the aluminum part conductivity.
Steel-aluminum wires are not an alloy, they contain separately aluminum and steel parts. The steel part is internal, and the aluminum part is external. The main purpose of the aluminum part is its high electrical conductivity, and the steel part provides the wire with mechanical strength.
There are several grades of steel-aluminum wires, ones are used only on land in areas without aggressive impurities in the air, the others are designed for the use in areas with high humidity, near seas and chemical plants.
Steel-aluminum wires for power transmission lines are made with a different ratio of the aluminum section to the steel part section depending on the required operating conditions.
Our company offers non-insulated electric wires of the brands most popular in Russia: А, АС, АСКС, М, СИП-1, СИП-2, СИП-3, СИП-4, СИП-5, СИП-1А, СИП-2А. We organize supplies of conductor products by any mode of transport to all regions of the country. Wires are manufactured in strict accordance with modern technological standards, fully meet the requirements of the applicable State Standard and maintain the cost-efficiency and performance of overhead lines at the proper level.