The Basic knowledge of overhead transmission

The Basic knowledge of overhead transmission


1,Basic composition of overhead transmission lines

The line connecting the power from the power plant to the power load center and the communication line between the power systems are transmission lines. Overhead transmission lines are generally composed of towers, foundations, wires, ground wires (including OPGW ), insulators, fittings, and grounding facilities.

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2, Pole and Tower

Pole and tower are rod-shaped or tower-shaped structures that support overhead transmission line conductors and overhead grounding lines to keep a safe distance between them and between the earth. The towers are usually made of steel, wood and reinforced concrete structures in the world wide. The rod-shaped structure of wood and reinforced concrete is usually called a rod, and the tower-shaped steel structure and the reinforced concrete chimney structure are called towers. A tower without a cable is called a self-supporting tower, and a tower with a cable is called a cable tower.



The underground part of the transmission line tower is generally referred to as the foundation except for the grounding device. The role of the tower foundation is to support the tower and transmit the load to the earth. There are many types of tower foundations, which should be determined comprehensively according to the type of tower used, the terrain along the line, engineering geology, hydrology and construction transportation.


4,Grounding wire & conductors

Conductor is an element used to conduct electrical current and deliver electrical energy. Commonly used wires for overhead lines are All aluminum conductor(short as AAC), All aluminum alloy conductor(AAAC), Aluminum conductor aluminum alloy reinforced(ACAR), Aluminum conductor steel reinforced(ACSR), All aluminum alloy conductor steel reinforced(AACSR), Aluminum conductor aluminum clad steel reinforced(ACSR-AW/ACSR-AS) , Aluminum alloy conductor aluminum clad steel reinforced, high conductivity hard aluminum conductor steel reinforced, high conductivity aluminum conductor aluminu alloy reinforced, medium-strength aluminum alloy conductor, over head heat resistant aluminum alloy conductor steel reinforced, carbon fiber composite conductor and so on. The grounding wire is generally erected directly on the top of the tower and connected to the grounding device through a pole tower or a grounding down conductor. Commonly used overhead grounding wires are galvanized steel wire, aluminum-clad steel stranded wire and fiber-optic composite overhead grounding wire.

With more than 10 years’ manufacturing experience, Raise Cable Group can manufacture and supply various cables, such as bare conductors, aerial bundled cables, power cables, control cables, special purpose cables.


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