A cable is usually a rope-like cable made by twisting several or several sets of wires (at least two in each group). Each set of wires is insulated from each other and often twists around a center. The entire bread has a height. Insulation coating. They are set up in the air or installed underground and under water for telecommunications or power transmission. Cables can be divided into power cables, communication cables, and control cables according to their use. So when the cable is used, is there any security requirement? What is its protection measure? How to store it? The details are as follows:
1. When the cables cross each other, the high voltage cable should be under the low voltage cable. If one of the cables is protected by a pipe within 1m before and after the intersection or separated by a partition, the minimum allowable distance is 0.25m.
2. When the cable is approaching or intersecting with the heat pipe, the minimum distance between parallel and crossover is 0.5m and 0.25m, respectively, if there is thermal insulation measures.
3. Pipes should be protected when they intersect with railways or roads. Protection pipes should extend beyond the track or road 2m away.
4. The distance between the cable and the building foundation should ensure that the cable is buried outside the building's loose water; when the cable is introduced into the building, the pipe should be protected and the protection pipe should be beyond the building's loose water.
5. The distance between the cable directly buried in the ground and the grounding of the general grounding device shall be 0.25~0.5m; the buried depth of the cable directly buried in the ground shall not be less than 0.7m, and shall be buried under the frozen soil.
With the rapid development of the buried construction of power cables, the higher requirements for cable protection, the cable protection sleeve is made of polyethylene PE and high-quality steel pipe after sandblasting, blasting or coating, and heat curing. Process made. It is an electrical insulation tube that is most commonly used to protect wires and cables. Because it has good insulation properties, high chemical stability, no rust, no aging, can adapt to harsh environments and is widely used.
The use of cable protection sleeves to protect the cable can achieve the following advantages:
1, good corrosion resistance, long life, can be used in the wet saline-alkaline zone.
2, flame retardant, heat resistance, can be used under 130 degrees of high temperature without deformation, in case of fire does not burn.
3, high strength and high rigidity. Used directly under the carriageway without the need for additional concrete protection, can roll the construction progress of the cable project.
4. Cable protection sleeves, whether they are pipes or fittings, have a certain degree of flexibility, which can withstand the damage caused by external heavy pressure and foundation settlement.
5, has a good anti-interference signal performance.
6. The inner wall is smooth and does not scratch the cable. The design adopts socket-type connection to facilitate the installation and connection. The rubber sealing ring seal at the joint not only adapts to thermal expansion and contraction, but also prevents mud sand from entering.
If the cable is to be stored for a long period of time, the following considerations should be taken, depending on where the cable is placed:
1, under the roof. Cables can only be used if they are not directly exposed to sunlight or ultra-high temperatures. Standard LAN cables can be used. Pipes are recommended.
2, on the outside wall. Avoid direct sunlight on the wall and human damage.
3, in the pipeline (plastic or metal). If in the pipe, pay attention to the damage of the plastic pipe and the heat conduction of the metal pipe.
4, suspended applications / overhead cables. Consider the sagging and pressure of the cable, which kind of binding method you intend to use, and whether the cable is exposed to direct sunlight.
5, laid directly in the underground cable trench, this environment is the smallest control range. The installation of cable trenches should be regularly checked for dryness or moisture level.
6, underground pipelines. In order to facilitate future upgrades, cable replacement and isolation from surface pressure and surrounding environment, auxiliary pipelines are isolated, and auxiliary piping is a better method. But don't expect the pipeline to stay dry forever, which will affect the choice of cable types.