The so-called ABC Cable is relative to the cable, that is, the line where the wire is erected at a certain height by the tower to transmit electric energy. The ground insulation of overhead lines of high-voltage transmission and distribution networks is generally based on air. In the past, distribution lines (below 10kV except 380V) generally used bare wires. However, due to the complex distribution environment in urban areas, short-circuit grounding and lightning strike lines often occur Therefore, insulated wires are generally used for overhead lines below 10kV (that is, the outer layer of the wire is wrapped with an insulating layer). This is the so-called insulated overhead wire insulated cable, which is often called overhead insulated wire. The following is also Called overhead insulated wire. Here we mainly introduce the characteristics and application areas of overhead insulated cables for 10kV.
1. Main features of overhead insulated conductors
1.1 Good insulation performance
Due to the extra layer of insulation layer, the overhead insulated wire has superior insulation performance than the bare wire, which can reduce the distance between lines, reduce the insulation requirements for the support parts of the line, and increase the number of circuits of the line erected on the same pole.
1.2 Good corrosion resistance
Due to the insulating layer on the outer layer, the overhead insulated wire is less oxidized and corroded than the bare wire, and has stronger corrosion resistance, which can prolong the service life of the line.
1.3 Anti-external damage
Reduce the influence of external factors such as trees, flying metal film and dust, and reduce phase-to-phase short circuit and grounding accidents.
1.4 The strength meets the requirements
Although the insulated wire lacks the steel core, it is tough, so that the mechanical strength of the entire wire can meet the stress design requirements.
2 . Application areas of overhead insulated conductors
2.1 Suitable for places with many trees
For lines erected with bare wires, in areas with many trees, the erection and maintenance of lines often have great contradictions with greening and forestry. The use of overhead insulated wires can reduce the felling of trees (in the initial stage of erection and the stage of operation and maintenance), solve many problems, and reduce the contradictions with greening, forestry and other departments, protect the ecological environment, beautify the city appearance, and reduce the line grounding Fault.
2.2 Suitable for areas with a lot of flying metal dust and pollution
In the old industrial area, metal processing enterprises often have metal dust flying in the wind due to environmental protection not up to standard. In the polluted areas of thermal power plants and chemical plants, short circuits and ground faults are caused in overhead power distribution lines. The use of overhead insulated conductors is a better way to prevent short-circuit grounding of 10kV distribution lines.
2.3 Suitable for salt spray areas
Salt spray corrodes the bare wires quite seriously, greatly reducing the tensile strength of the bare wires. When encountering wind and rain, the wires will break, causing short-circuit grounding accidents and shortening the service life of the wires. The use of overhead insulated wires can better prevent salt spray corrosion. Because there is a layer of insulating layer protection, it can reduce the corrosion of conductors by salt spray, delay the aging of lines, and prolong the service life of lines.
2.4 Applicable to areas with more lightning
Because the ABC Cable has a layer of insulation protection, it can reduce the lightning caused by the line. Even if there is lightning, the impact will be much smaller. In minefields; for lines erected with bare wires, the line insulation generally drops rapidly, and burst grounding accidents often occur. After the overhead insulated conductor is replaced, the power outage time of the ground fault can be reduced.
2.5 Applicable to the renovation of old urban areas
Since the ABC Cable can withstand a voltage of 15kV, the minimum vertical distance between the insulated wire and the building is 1m: and the horizontal distance is 0.75m. Therefore, replacing the low-voltage main line with 10kV overhead insulated wires and directly sending them into the load center to shorten the power supply radius of the low-voltage power grid is an effective power distribution method for old city renovation.
2.6 Conducive to typhoon protection
Due to the poor typhoon resistance of the overhead bare conductor lines, once the typhoon arrives, the line trips one after another. After the overhead insulated wire is used, the instantaneous collision of the wires will not cause a short circuit, which reduces faults and greatly improves the typhoon resistance of the line.
