Wire and cables are generally rope-like cables twisted by several wires or groups of wires. Each group of wires is insulated from each other and is often twisted around a center. The entire outside is covered with a highly insulating coating. Most of them are erected in the air or installed underground or underwater for telecommunications or power transmission. Cables can be divided into power cables, communication cables and control cables according to their uses. So what are the safety requirements when using wires and cables? How should it be stored in general?
security requirements
- When the cables cross each other, the high-voltage cables should be under the low-voltage cables. If one of the cables is protected by a pipe or separated by a partition within 1m before and after the intersection point, the minimum allowable distance is 0.25m.
- When the cable is close to or crosses the heat pipe, if there are heat insulation measures, the minimum distances for parallel and crossing are 0.5m and 0.25m respectively.
- When the cable crosses the railway or road, it should be protected by wearing a pipe, and the protective pipe should extend 2m beyond the track or road.
- The distance between the cable and the foundation of the building should be able to ensure that the cable is buried outside the scattered water of the building; when the cable is introduced into the building, it should be protected by a pipe, and the protective tube should also be beyond the scattered water of the building.
- The distance between the cable directly buried in the ground and the grounding of the general grounding device should be 0.25~0.5m; the burial depth of the cable directly buried in the ground should generally not be less than 0.7m, and should be buried under the frozen soil layer.
storage method
If the cables are to be stored for a long time, the following considerations should be made according to the location of the cables:
- Laying directly in the underground cable trench, this environment has the smallest control range. The installation of the cable trench should be regularly inspected for dryness or humidity.
- Under the eaves. The cables are only suitable if they are not exposed to direct sunlight or extreme heat. Standard LAN cables can be used. Conduit is recommended.
- Suspended applications/overhead cables. Consider cable sag and stress, what type of bundling you plan to use, and whether the cable will be exposed to direct sunlight
- On the outer wall. Avoid direct sunlight on the wall and man-made damage.
- Underground pipelines. In order to facilitate future upgrades, cable replacement and isolation from surface pressure and the surrounding environment, auxiliary piping is a better method. But don’t hope that the pipe will stay dry forever, which will affect the choice of cable type.
- Inside the pipe (plastic or metal). If it is in the pipeline, pay attention to the damage of the plastic pipeline and the heat conduction of the metal pipeline.
