Cable Safety and Protection

Safety requirements
1. When cables cross each other, high-voltage cables should be below low-voltage cables. If one of the cables is protected by pipes or separated by partitions within 1m before and after the intersection, the minimum allowable distance is 0.25m.
2. When the cable is close to or crosses the thermal pipeline, if there are insulation measures, the minimum distances for parallel and crossover are 0.5m and 0.25m respectively.
3. When the cable crosses the railway or road, it should be protected by pipes, and the protective pipe should extend 2m beyond the track or road surface.
4. The distance between the cable and the foundation of the building should ensure that the cable is buried outside the building's scattered water; when the cable is introduced into the building, it should be protected by pipes, and the protective pipe should also extend beyond the building's scattered water.
5. The distance between the cable directly buried underground and the grounding of the general grounding device should be 0.25~0.5m; the burial depth of the cable directly buried underground should generally not be less than 0.7m, and it should be buried under the frozen soil layer.
Protection measures
With the rapid development of underground laying of power cables, higher requirements are put forward for cable protection. Cable protection sleeves are made of polyethylene PE and high-quality steel pipes through sandblasting and shot blasting pre-treatment, plastic dipping or coating, and heating and curing processes. It is the most commonly used electrical insulation tube for protecting wires and cables. It is widely used because of its good insulation performance, high chemical stability, no rust, no aging, and adaptability to harsh environments.
Using cable protection sleeves to protect cables can achieve the following advantages: 1. Good corrosion resistance, long service life, and can be used in humid saline-alkali areas. 2. Flame retardant and heat resistance, can be used for a long time at a high temperature of 130 degrees without deformation, and will not burn when exposed to fire. 3. High strength and high rigidity. It is used directly buried under the roadway without adding a concrete protective layer, which can speed up the progress of cable engineering construction. 4. Cable protection sleeves, whether pipes or pipe fittings, have a certain flexibility and can resist damage caused by external pressure and foundation settlement. 5. It has good resistance to external signal interference. 6. The inner wall is smooth and does not scratch the cable. The design adopts a socket-type connection method, which is convenient for installation and connection. The rubber sealing ring at the joint can adapt to thermal expansion and contraction and prevent mud and sand from entering.
Storage method
If the cable is to be stored for a long time, the following considerations should be made according to the placement of the cable:
1. Under the eaves. The cable can be used as long as it is not directly exposed to sunlight or ultra-high temperature. Standard LAN cables can be used. It is recommended to use pipes.
2. On the exterior wall. Avoid direct sunlight on the wall and human damage.
3. In the pipe (plastic or metal). If in the pipe, pay attention to the damage of plastic pipes and the heat conduction of metal pipes.
4. Suspended application/overhead cable. Consider the droop and pressure of the cable, which bundling method is intended to be used, and whether the cable is directly exposed to sunlight.
5. Directly laid in the underground cable trench, this environment has the smallest control range. The installation of the cable trench should be regularly checked for dryness or humidity.
6. Underground pipeline. In order to facilitate future upgrades, cable replacement and isolation from surface pressure and the surrounding environment, auxiliary pipelines are isolated. Auxiliary pipelines are a better method. But don't expect the pipes to stay dry forever, as this will affect your choice of cable type.