400kv Overhead Power Transmission Lines Stringing Equipment Tools manufacturer
A 400kV overhead power transmission line stringing project involves the installation of high-voltage conductors and earth wires on transmission towers designed for 400kV operation, ensuring efficient and reliable power transfer over long distances.
Key Components and Materials:
Conductors: Typically ACSR (Aluminum Conductor Steel Reinforced) types such as Twin Moose, with specifications like 54 strands of aluminum and 7 strands of steel, diameter ~31.77 mm, current capacity ~950 Amps, and tensile strength around 161 kN.
Earth Wire: Usually two earth wires are installed for lightning protection, made of galvanized steel strands, diameter ~10.98 mm, tensile strength ~68 kN.
Insulators: Pin, disc, long rod, anti-fog, or polymer types rated for 11kV per unit, assembled in strings to withstand 400kV line voltage.
Accessories: Vibration dampers, bundle spacers, suspension clamps, tension clamps, and repair sleeves to maintain mechanical integrity and reduce conductor oscillations.
Stringing Methods
| Method | Description | Applicability |
|---|---|---|
| Slack/Stringing Layout | Conductor is dragged along the ground or laid out on wooden blocks; low tension; cheaper but risk of conductor damage | Flat terrain, non-critical lines, easy access |
| Tension Stringing | Conductor is pulled under controlled tension to keep it off the ground and obstacles; ensures minimal damage | Most common for 400kV lines, especially in difficult terrain |
| Helicopter Stringing | Use of helicopters to carry pilot lines and conductors over inaccessible or rugged terrain | Mountainous or environmentally sensitive areas |
The controlled tension method is preferred for 400kV lines to maintain conductor integrity and safety, using tensioners, pullers, and reel stands.
Stringing 400kV overhead transmission lines requires specialized equipment and tools to ensure safety, efficiency, and the integrity of conductors and accessories. Below is a comprehensive overview of the core equipment and tools typically used in such projects.