Cable tell you the importance of cable inspection

　　Cables, known as the blood vessels and nerves of the national economy, are related to the safety of the transmission of information and communication, the operation of industrial minerals, and the operation of railway traffic. They are inseparable from people’s production and life. The order of life has a huge impact. Therefore, our country attaches great importance to the construction, operation and maintenance of cables. However, the current quality of domestic wires and cables is worrying. So, don't worry about how cheap the cables are. First, check if there are any of the following common test items?

　　1. Electrical performance testing

　　Mainly there are conductor DC resistance, insulation resistance, finished product voltage test and insulated wire core voltage test, each of which is very important. Conductor resistance directly reflects the electrical transmission performance of the cable, and directly affects the temperature, life, voltage drop, and operational safety of the cable during energized operation. It mainly examines the material and cross-sectional area of the conductor. If the material of the conductor is not good or the cross-sectional area is serious Insufficient, it will cause the conductor DC resistance to seriously exceed the standard.

　　Insulation resistance, finished product voltage test and insulated wire-core voltage test all examine the electrical insulation performance of the cable insulation layer and sheath layer. Insulation resistance is to detect the resistance of the insulating material between two conductors. It should be large enough. To insulation protection.

　　2. Mechanical performance testing

　　The main purpose is to examine the tensile strength and elongation at break of insulation and sheath plastic materials, including before and after aging, as well as the bending test, bending test, load breaking test, insulation core tearing test for finished flexible cables, Static torsion test, etc. Tensile strength before and after aging, elongation at break before and after aging are the most important and basic indicators of cable insulation and sheath materials. It is required that the materials used for cable insulation and sheath have sufficient tensile strength and are not easy to break. It must also have a certain degree of flexibility.

　　In addition, since flexible cables are not fixedly laid, there are repeated pulling and bending during use. Therefore, the standard for flexible cables additionally stipulates that dynamic bending tests, bending tests, load breaking tests, and insulated cores should be added to the finished cables. Tearing test, static bending test, etc., to ensure that this cable meets the requirements in actual use.

　　3. Performance test of insulation and sheath materials

　　Including thermal weight loss, thermal shock, high-temperature pressure, low-temperature bending, low-temperature stretching, low-temperature impact, flame retardant properties, etc., these are all tests for the performance of insulation and sheath plastic materials. The flame retardant performance of the cable is very important. The test to examine this performance is the non-flame test, that is, the finished cable installed according to the standard is ignited with a special flame for a certain period of time, and the flame of the cable is checked after the flame is self-extinguished. , Of course, the less burnt part, the better, which means that its flammability is poor, its flame retardancy is good, and the safer it is.

　　4. Logo inspection

　　The standard requires that the cable packaging should be accompanied by a label or logo indicating the product model, specification, standard number, factory name, and place of origin. Specifications include rated voltage, number of cores and nominal conductor cross-section, etc.; the surface of the cable should be printed with continuous signs of the manufacturer's name, product model and rated voltage, and the spacing of the signs should be ≤200mm (insulation surface) or ≤500mm (sheath surface), The content of the mark should be complete, clear and scratch-resistant. This requirement is to facilitate the user to understand the cable model specification and voltage level to prevent laying errors.

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