Company Name: Henan Xinchaoda Cable Co., Ltd.
Contact: Manager Guo
Address: Xibaishui Village, Xitao Town, Wuzhi County
Marketing Center: 1812, Building B, Building 3, Shenglong Plaza, Zhengdong New District, Zhengzhou
1 secondary characteristics of overhead insulated conductors
Good insulation function: The overhead insulated wire has an extra insulation layer, which has better insulation function than the bare wire. It can increase the interval between lines, reduce the insulation requirements for line support, and improve the number of circuits installed on the same pole.
Good anti-corrosion function: Because the outer insulated wire has an insulating layer, the level of oxidative corrosion is less than that of the bare wire, and the anti-corrosion ability is stronger, which can extend the service life of the line.
Protection against external damage: It can increase the influence of internal factors such as trees, flying objects, metal films and dust, and increase phase-to-phase short circuit and grounding accidents.
Strength reach requirement: Although the insulated wire has less steel core, it is tough, so that the machine strength of the whole wire reaches the requirements of stress design.
2 Specifications of overhead insulated conductors
Core: There are two types of overhead insulated conductors: aluminum core and copper core. In the distribution network, aluminum core wires are used more often. Secondly, aluminum materials are lighter and cheaper. The requirements for line connectors and support parts are low. In addition, the original power distribution wires are mainly steel core aluminum stranded wires. , Select the aluminum core wire to facilitate the connection with the original network. In practice, more aluminum core wire is also used. The copper core wire is used as the down-conductor of the transformer and the switchgear.
Insulation information: The insulation maintenance layer of overhead insulated conductors has two types: thick insulation (3.4mm) and thin insulation (2.5mm). Thick insulation allows frequent contact with trees during operation, thin insulation allows only short-term contact with trees. The insulation maintenance layer is further divided into cross-linked polyethylene and light-weight polyethylene, and the insulation function of the cross-linked polyethylene is better.
3 Overhead insulated conductor laying method
Single conventional laying method. This erection method is to use the conventional cement poles, iron accessories and ceramic insulator accessories of the bare wires, and stop the erection according to the bare wire erection method, which is more suitable for the area where the old lines stop being rebuilt and the corridor is full. A single insulation is used to suspend the wires by using a special insulation support. This method can increase the number of circuits erected, save line corridors, and reduce the unit cost of the line.
4 Area for use of overhead insulated conductors
Applicable to the center of many trees: For the lines erected by bare wires, in the areas with many trees, the erection and maintenance of the lines often have a large shield against greening and forestry. The use of overhead insulated wires can increase the felling of trees (in the initial stage of erection and operation and maintenance), solves many problems, and also increases conflicts with greening, forestry and other departments, maintains the ecological environment, ugliness the city appearance, and reduces the line. Ground fault.
For areas with many flying metal dust and multiple purification. In old industrial areas, due to environmental protection standards, metal processing companies often have flying metal dust flying in the wind. In the purification areas of thermal power plants and chemical plants, short circuits and ground faults in overhead power distribution lines are formed. The use of overhead insulated conductors is a better way to avoid short circuit to ground on 10 kV distribution lines.
Applicable to salt fog areas: The salt fog corrodes the bare wires very seriously, which greatly reduces the tensile strength of the bare wires. When it encounters wind and rain, it causes the wires to break, forming a line short circuit and grounding accident, and prolonging the service life of the lines. The use of overhead insulated wires can better prevent salt spray corrosion. With the maintenance of an insulation layer, it can increase the corrosion of conductors caused by salt spray, delay the aging of the line, and extend the service life of the line.
It is suitable for areas with a lot of lightning: overhead insulated wires have a layer of insulation and maintenance, which can reduce line lightning. Even if there is lightning, the impact will be much smaller. In minefields, lines insulated with bare wires generally experience a rapid decline in line insulation, often resulting in burst grounding accidents. After replacing with overhead insulated wires, it can increase the number of ground faults.
Suitable for old city reconstruction: As the overhead insulated wire can accept a voltage of 15kV, the minimum vertical distance between the insulated wire and the building is 1m, and the degree interval is 0.75m. Therefore, replacing the high-voltage branch line with 10kV, overhead insulated conductors and indirectly feeding it into the load center, extending the radius of the high-voltage grid is a fruitful distribution method for old city reconstruction. Conducive to typhoon protection. As the anti-typhoon resistance of overhead bare conductor lines is poor, once the typhoon arrives, the line trips one after another. After the overhead insulated wires are used, the wires will not cause a short circuit when they meet, which increases the fault and greatly improves the ability of the line to resist typhoons.