The Power line Stringing blocks that have different diameters are used to string diverse conductors. Our Large diameter stringing blocks are of High strength and flexibility, lightweight, and long service. It defends both the cable and conductor from friction when they are resting and they can save a lot of time and effort.
Description of power line stringing blocks
We manufacture a lot of power line stringing block models for diverse uses in overhead transmission line building. They are used to support conductors, and communication lines.
The sheave of the stringing blocks is made from high-strength nylon or aluminum materials, and the frame of the blocks is made of steel. All kinds of stringing pulley-blocks can be made according to the customers’ requirements.
How to use stringing blocks to pay conductors overhead transmission lines?
The transmission line is an important part of the power system and the cost and life of the transmission lines chiefly depend on the material used for collecting conductors for the transmission line. The most significant and most suitable material for the conductor of the transmission lines is copper as it has a high transmission and high tensile strength. Also, it is having good ductility and the only limit is its cost. The most extensively used material in a transmission line is Aluminium.
A stringing Pulley is a roller, which is made of high-strength nylon, or quality steel, the outer diameter ranges 916mm, with numerous sheaves from a single to nine pulleys to couple with a steel edge to work above the power line. Rendering to its sheave number, it can be useful for different split conductors. For these features, It is widely and proficiently used in numerous electric power line transmission buildings.
Why Aluminium is not used here?
Aluminium is having satisfactory conductivity. More ever it is very light in weight. The only restraint is the low tensile strength. To overcome this strength is used in steel for increasing the ductile strength of aluminium conductors such as in Aluminium conductor steel armored conductors. This conductor is much more general for very high voltage overhead broadcast lines. The choice of appropriate material for the Transmission line depends on the following
- Obligatory electrical properties
- Obligatory mechanical strength
- The Cost of the material
Possessions of Materials Used in Transmission Line
- Very High conduction
- Very High stretchable strength
- Very Lightweight
- Very High clash to corrosion in weather conditions
- Great thermal constancy
- Very low amount of thermal expansion
- Low cost
The Materials Used for Transmission Lines
The Resources used for transmission lines are
- Cadmium alloys
- Galvanized steel
- Phosphor bronze
The most widely used, high conduction material for electrical machines, is copper. Flexibility, weldability, and solderability are the most important properties of copper. Copper in pure form is having good conduction. But the conductivity of copper is concentrated due to the presence of impurities.
The Properties of Copper
- Resistivity is 1.68 µΩ -cm
- Melting point is 1085oC
- Specific gravity is 8.96gm /cm3.
Copper is the most important and much appropriate material for the Transmission line as it has very high conductivity and high supple strength. The only limit is its cost.
Aluminium is a constituent that is a lightweight, non-magnetic, and soft metal. Aluminum is having a low density, high ductility as in stringing pulley, corrosion confrontation, and good conduction, which makes it suitable to use as an electric conductor for transmission and distribution of electricity.
Possessions of Aluminum
- The Resistivity is 2.65 µΩ -cm.
- Temperature coefficient at 20oC.
- The Melting point is 660oC.
- Specific gravity is 2.70 gm/cm3.
The most extensively used material in transmission lines is Aluminium. Aluminium is having satisfactory conductivity. The restraint is low tensile strength. To overcome the restraint, a steel core is used to rise the tensile strength of aluminum conductors as in Aluminum conductor steel conductors. This is very general for high voltage transmission lines.
Cadmium – Copper Alloy
The cadmium copper alloys comprise cadmium from 0.6%. This minor addition of cadmium upsurges the tensile strength and corrosion resistance of copper. The conduction of cadmium copper alloy is 90%, pure copper. This is used for making conductors for tensile strength communication lines and in Heating pads.
Phosphorus is added as a deoxidizing agent during the melting process. Phosphor bronze has strength, toughness, a low factor of friction, and fine grains. The addition of phosphorus upsurges the fluidity of molten, which grades in better castability of alloy, and cleans up the boundaries which improves the properties of the alloy. This is used for making conductors for transmission lines passing through the atmosphere. It is used for the creation of spring where high confrontation with tiredness is required.
Iron gets rusted in open weather conditions. To avoid corrosion, metals are covered with Zinc. In this process, the iron is dipped in Zinc at a temperature of 449oC. When visible to the atmosphere, zinc reacts with oxygen and forms zinc oxide, which reacts with carbon dioxide and forms zinc carbonate. This is typically a dull and strong material, which protects the iron or steel underneath from corrosion in open weather conditions. Galvanized steel is used for making conductors which are also used in transmission lines in which resistance to corrosion is compulsory. Galvanized steel sheets are also used for making transmission poles.
This is called a copper-clad conductor. For high tensile strength to upsurge the strength of wire, steel is used as a core of the conductor for collecting the conductivity of the conductor. Here, copper not only delivers conductivity but also works as a defensive layer to stop the corrosion of steel by weather conditions. Steel core wire is used for earthing electrical connections.
Steel Core Aluminium
Aluminum is very light in weight and has very good conductivity. But it has a very low tensile strength. To make it appropriate for the transmission line, we should increase its tensile strength. To increase the tensile strength, steel is used as the conductor. As it has a very high tensile strength, it has good conductivity and it is economical.