What are the precautions for wire and cable field repair?
Wheel Hub Assembly For LINCOLN SHAOXING ZHENGHONG AUTO PARTS CO.LTD , https://www.kontinental-bearing.com
In order to facilitate the smooth progress of the cable repair work, the construction unit should be equipped with small outdoor generators. At the same time, it is convenient for repair at the scene. The quality of the plastic welding torch now provided is excellent. The nozzle heating area is large, and the heating speed is faster. In addition, the damaged part of the cable laying process is random. In general urban and plain areas, this work is better carried out. However, in some mountainous areas, due to the effect of receiving complex terrain, the cable repair work is actually very difficult. Therefore, to reduce the investment in the corresponding aspects and solve the problem quickly, a key issue is that the number of personnel in the cable laying process must be sufficient, and the formal cable laying equipment should be used to carry out formal line-up, avoiding and reducing the occurrence of cable dropouts. Damaged jacket.
The field repairing technology of the cable is not very high. After the cable is damaged, it must be confirmed that the cable is not damaged inside, and then the cable is repaired, otherwise the actual repair of the cable jacket It is not meaningful. The repair of the cable must be timely, otherwise the external moisture and moisture will enter for a long time, which will affect the service life of the cable. After the laying of cable ends in Meiyu rain in the south, the end of the cable was not sealed in a timely manner, causing the moisture in the cable channel to enter the end of the cable 10-20 meters. All blackened, resulting in the waste of the cable after laying, so the laying of the cable should still strengthen the appropriate aspects of inspection, maintenance and storage, to prevent the cable before the use of electricity on the site should be a variety of external factors caused by shortening the cable life and end .
Some of the tools and materials used for field repair of cables must also be fully prepared. Plastic welding torches are essential, high-voltage insulating tapes, waterproof tapes and plastic insulation and sheathing to peel off the skin, and other sealing materials must also be prepared because the cables Insulation jacket material is mainly divided into cross-linked polyethylene, polyethylene, polyvinyl chloride and other materials. Some materials are thermosetting materials, such as cross-linked polyethylene insulation can not be repeated melting and reuse, in the field with raw materials for repair, can only be repaired with high-voltage insulating tape and repair tape series provided by the United States 3M company. And some materials are thermoplastic materials, which can be completely melted and used again with high temperature, such as polyethylene, polyvinyl chloride and other materials, and can be obtained on site. The edge sheath cut from the cable ends is cut into thin strips. It can achieve the repair of low voltage cable insulation and jacket, and its repair quality can fully meet the requirements of the cable's normal service performance. Another treatment for the occurrence of sheath damage in the process of laying the medium-voltage cable on site cannot be too rough. One is that the laying process of the cable must be handled gently, and after another cable is damaged externally, the internal insulation is sometimes damaged. It's hard to say that the author once carried out a factory-return test on the cables that caused the outer sheath to be damaged in some cases because of careless construction on the site. It was found that the broken parts of the cables had partial discharge and breakdown phenomena. Therefore, for medium-voltage power cables, After the outer jacket is damaged during the laying process, it is better to cut off the middle joint or replace the cable, because the hidden part of the damaged part of the cable may be used.
Facts have proved that for the repair of low-voltage cable insulation and jacket must be a relatively minor damage to the cable, only damage to the insulation and jacket, the other cable is intact, the insulation and jacket can be repaired, and the high voltage The requirements for cables may be more stringent. Nowadays, in some projects, the cable transmission is to reduce the number of intermediate joints of cables. All cables use large-length single-core cables. Because of the long distance between the laying of lines and the terrain, and the number of construction personnel With the lack of professional cable laying equipment and other factors, the occurrence of damage to the cable jacket during construction has greatly increased. In some constructions, after the above-mentioned problems occur, it is irresponsible to use a common tape to pack a bag casually. There is no knowledge about the damage inside the cable breakage point, and the cable is likely to have insulation breakdown or quality problems in the on-site completion test process and later run process.