How to prevent wire and overhead cable failure？
The main preventive method for the failure of overhead cables?
1. Do a good job of calculating the short-circuit current, correctly select and calibrate electrical equipment, and make the rated voltage of the electrical equipment consistent with the rated voltage of the line.
2. Correctly select the rated current of the relay protection and use a quick-break protection device so that the short-circuit current can be quickly cut off in the event of a short-circuit, reducing the duration of the short-circuit current and the losses caused by the short-circuit.
3. By installing lightning arresters near the transformer and on the lines, and installing lightning rods in substations, the damage to the wires from severe weather can be reduced.
4. Zhengzhou Jinshui Cable Group uses reactors to increase system impedance and limit short-circuit current.
5. Remove the faulty circuit or device from the power system so that the remaining components can continue to work.
6. It is forbidden to pull the knife switch with load and close the grounded knife switch with power. The ground wire should be removed immediately after the line construction is completed. It is necessary to conduct patrol inspections on lines and equipment frequently, find defects in time, and quickly carry out maintenance.
7. Ensure the construction quality of overhead cable, strengthen line maintenance, and always keep the line sag consistent and comply with regulations.
8. When installing and overhauling electrical equipment with live electricity, it is necessary to prevent miswiring and misoperation, and to take measures to prevent short circuit when working at parts that are close to live parts.
9. Strengthen management to prevent small animals from entering the power distribution room and climbing onto electrical equipment. Remove conductive dust in time to prevent conductive dust from entering electrical equipment.
What are the measures to reduce the faults of XLPE cable lines?
1. Regularly maintain and update cables
Although the anti-aging performance of xlpe insulated power cable is higher, it does not mean that there will be no aging. Therefore, in order to reduce line failures, enterprises should maintain them regularly, especially cables that have been used for more than ten years should be updated in time. This can effectively reduce cable failure and provide a good guarantee for the safe operation of the cable.
2. Avoid installing in poorly ventilated places
If the dissociation of the air gap inside the insulation of the cross-linked cable will cause local overheating, carbonization of the insulating material, resulting in a decrease in dielectric strength, it may lead to line failure. Therefore, enterprises should avoid installing XLPE cables in poorly ventilated places such as cable-dense areas, cable trenches, and cable tunnels during installation, so as to reduce the chance of line failure.
3. Use good cable accessories and keep them tight
Cable accessories are a kind of supporting facilities that need to be used when installing cross-linked cables. If the connection tube of the cable is not crimped firmly during the installation of cable accessories, it will cause the contact resistance of the cable to increase, and thus cause local overheating. If it is not resolved for a long time, it will cause line faults, so in order to avoid faults, you should use good quality cable accessories and ensure that the crimping is firm.
Precautions for indoor layout of wires:
1. Pipeline wiring is the basis of "living lines", which lays the foundation for future line maintenance, replacement and home intelligence.
2. Prevent the insulation layer of the wire from being damaged. If directly buried in cement mortar, the silicate may corrode the insulation layer of the wire, causing the insulation of the wire to drop and cause a short circuit;
3. Prevent fire. In the event of a short circuit of an electrical appliance causing the insulation layer of the wire to catch fire, the wire tube can prevent the flame from spreading, because the wire tube is made of flame-retardant material and will not burn itself, so it is usually called a "flame-retardant tube". If no conduit is used, it is dangerous to have other wires or flammable materials next to the wires.
Fourth, heat dissipation. Because the cross-sectional area of the wire is determined by the load, there is generally a margin when wiring, but it can still alleviate the heating of the wire caused by special circumstances.
In addition, our Zhengzhou Jinshui Cable Group will produce wires and cables in full accordance with the production standards stipulated by the international market, which greatly reduces the possibility of wire and cable failure.