Wires and cables are typically rope-like cables consisting of several or several groups of conductors twisted together. Each group of conductors is insulated from each other and often twisted around a core. The entire cable is covered with a highly insulating coating. They are often installed overhead, underground, or underwater for telecommunications or power transmission. Cables can be categorized by their purpose as power cables, communications cables, and control cables. So, what are the safety requirements for using wires and cables? How should they generally be stored?
01
Safety Requirements
1. When cables cross each other, high-voltage cables should be placed below low-voltage cables. If one cable is protected by conduit or separated by partitions within 1 meter before and after the intersection, the minimum allowable distance is 0.25 meter.
2. When cables are close to or cross thermal pipes, if insulation is in place, the minimum distances for parallel and crossing connections are 0.5 meter and 0.25 meter, respectively.
3. When cables cross railways or roads, they should be protected by conduits, and the protective conduits should extend 2 meters beyond the track or road surface.
4. The distance between the cable and the building foundation should ensure that it is buried outside the building's sloping water. When entering a building, the cable should be protected by conduit, which should also extend beyond the building's sloping water.
5. Cables directly buried underground should be 0.25-0.5m away from the grounding of a general grounding device. The burial depth of cables directly buried underground should generally be no less than 0.7m and should be buried below the permafrost layer.
02
Storage Methods
If cables are to be stored for a long time, the following considerations should be made based on the cable placement:
1. Directly in an underground cable trench. This environment has the least controlled environment. The cable trench installation should be regularly inspected for dryness or moisture levels.
2. Under eaves. Standard LAN cables can be used as long as the cables are not exposed to direct sunlight or excessively high temperatures. Pipes are recommended.
3. Suspended applications/overhead cables. Consider cable sag and pressure, the intended bundling method, and whether the cables will be exposed to direct sunlight.
4. On exterior walls. Avoid direct sunlight and damage to the wall.
5. Underground pipes. To facilitate future upgrades and cable replacements, as well as to isolate the cable from surface pressure and the surrounding environment, installing auxiliary pipes is a good option. However, don't rely on the pipes remaining permanently dry, as this will affect your choice of cable type.
6. Inside pipes (plastic or metal). If inside pipes, be mindful of damage to plastic pipes and the heat conduction of metal pipes.
