The reason why the power cable
1. In the normal operation of the cable, if there is a breakdown such as breakdown for some reason, the water in the cable trench will enter the cable along the fault point; in civil construction, especially in the use of large construction machinery. In construction sites, cable breakage or breakdown accidents caused by various human factors are not uncommon. When such an accident occurs, the cable insulation is severely damaged, and it can also cause water to enter the cable.
2. After the cable laying is completed, the cable head cannot be made in time due to the limitations of the site construction conditions.
The unsealed cable fracture is exposed to the air for a long time, or even immersed in water, so that a large amount of water vapor enters the cable.
3. When the new cable is shipped from the factory, both ends are sealed with plastic sealing sleeves, but after a section is used according to the actual situation at the construction site, the remaining part is simply wrapped with plastic cloth to break the fracture. If it is not placed and sealed well, over time, water vapor will inevitably seep into the cable.
4. During the production of the cable head (including the terminal head and the intermediate joint), due to the negligence of the construction personnel, the newly processed cable end sometimes accidentally falls into the stagnant water on site.
5. When laying cables, it is necessary to often cross roads, bridges and culverts. Due to weather or other reasons, a lot of water often accumulates in the cable trenches. During the laying process, it is inevitable that the cable head will be immersed in water. Water enters the cable because the plastic cloth is not tightly wrapped or damaged; in addition, the outer sheath or even the steel armor is sometimes scratched during traction and pipe penetration. This phenomenon is particularly prominent when mechanical traction is used.