The cause of the cable heating

When the load current increases, the surface temperature of the cable will rise, and if it is not treated, the consequences are very serious. For example: PVC cable, the surface temperature is 70°C, and its surface temperature will be lower than 5-10°C. Therefore, below 60 °C, the surface temperature of the cable is basically safe, from the perspective of power maintenance, naturally the lower the temperature, the better.
During use, the reasons for the cable heating are:
1. The cable conductor resistance does not meet the requirements of the national standard, resulting in heat generation during use.
2. The selection of unsuitable cables leads to the small conductor section of the cable used, the cable is overloaded in operation, and after long-term use, the heating and heat dissipation of the cable are unbalanced and cause heat generation.
3. The cable installation arrangement is too dense, which is not conducive to ventilation and heat dissipation, or the distance between the cable and other heat sources is too close, which will affect the normal heat dissipation of the cable, and will also cause the cable to heat up during use.
4. The joint manufacturing technology is not good, the crimping is not tight, and the contact surface resistance of the connection part is large, resulting in the cable heating.
5. The insulation performance between the cables is poor, resulting in low insulation resistance, and heat generation will occur during use.
6. Part of the shell of the armored cable is damaged, and after entering the water, it will cause slow damage to the insulation performance, resulting in a gradual decrease in insulation resistance and causing heat generation during use.
If the cause cannot be identified and troubleshooted, thermal breakdown of insulation will occur under continuous power supply. If there is a short circuit between the wires, it can easily lead to a fire.