Cable tray manufacturers talk about the reasons for the aging of cable tray skin?
1. Damp condition of insulation. Generally, this kind of situation is relatively common, which usually occurs at the cable joint in the directly buried or arranged pipe. For example: the unqualified manufacture of cable tray joint and making joint in humid climate will make the joint enter water or mix with water vapor, which will form water branch under the effect of electric field, and gradually endanger the insulation strength of the cable.
2. Corrosion of chemical raw materials. When the cable tray is directly buried in the area with acid-base effect, the armor, lead skin or outer protective layer of the cable will be corroded. Due to long-term chemical corrosion or electrolytic corrosion of the protective layer, the protective layer will fail and the insulation will decline, which will also lead to the defects of the cable.
3. Long term overload operation. Overload operation, because of the thermal effect of the current, the load current through the cable must cause the conductor to heat, the skin effect of the same charge, the eddy current loss of the steel armor and the insulation medium loss will also produce additional heat, and then make the cable temperature rise. During long-term overload operation, too high temperature will accelerate the aging of insulation, resulting in breakdown of insulation. Especially in hot summer, the temperature rise of the cable often leads to the breakdown of the thin part of the cable insulation, so in summer, there are many disadvantages of the cable.
4. Disadvantages of cable joint. The bridge joint is a thin link in the cable line, and the defects of the cable joint caused by personnel's direct error (poor construction) often occur. In the process of making cable joints, if there are some original nets such as loose crimping and insufficient heating, the insulation of the cable head will drop, and then cause accidents.
5. Environment and temperature elements. The external environment and heat source around the cable bridge and cable will also cause the cable temperature to be too high, insulation breakdown, and serious explosion and fire.
6. External force is harmful. At that time, most of the cable defects were caused by mechanical hazards. For example: the cable laying equipment is not standardized construction, which simply constitutes a mechanical hazard; Civil engineering construction on directly buried cables will also reduce the cable hazards in operation. In some cases, the harm of the cable is not serious, and it may take several months or even years to present the defect of breakdown of the damaged parts. In some cases, the cable with serious damage may have the defect of short circuit, which directly affects the problems in the production days of the cable bridge and the power users.