What are the factors that affect the life of wire and cable?

The most direct reason for the low service life of the cable is the breakdown of the insulation reduction. There are many factors that reduce the insulation of the guide-sensitive cable. According to the actual operation experience, it can be divided into the following situations:

      1. External force damage: Many cable faults are caused by mechanical damage. When the cable is laid and installed, the construction is not standardized, causing mechanical damage; civil construction on the directly buried cable is also very easy to damage the cable in operation, and so on. If the damage is not serious, it may take several months or even years for the damaged part to break down completely to form a fault; if the damage is serious, it may directly cause a short circuit fault of the line, which directly affects the safety of electricity use.

      2. Insulation damp: generally occurs at cable joints in direct burial or in pipes. If the cable joint is not qualified and the joint is made in a humid climate, the joint will enter water or be mixed with water vapor. After a long time, water droplets will be formed under the action of the electric field, which will gradually damage the insulation strength of the cable and cause failure.

   3. Chemical corrosion: The cable is buried directly in the area with acid and alkali effect, which often causes the armor, lead or outer sheath of the cable to be corroded. lowered, resulting in cable failure.

      4. Long-term overload operation: Due to the thermal effect of the current, the conductor will heat up when the load current passes through the cable. At the same time, the skin effect of the charge, the eddy current loss of the steel armor, and the loss of the insulating medium will also generate additional heat, which will increase the temperature of the cable. . During long-term overload operation, excessive temperature will accelerate the aging of the insulation, and even the insulation will be broken down. Especially in hot summer, the temperature rise of the cable often causes the weak part of the cable insulation to be broken down first, so in summer, there are many cable failures.