The causes of cable overheating

When the resistance of the cable conductor does not meet the requirements, it will cause the cable to overheat during operation. When the voltage source is connected to the external load, it is considered that the internal resistance is in series with the external load. When using it, it is required that the internal resistance of the voltage source be as small as possible. When the voltage and material are the same, the better the material of the conductor, the lower the resistance. Power lines are generally made of copper coated aluminum or oxygen free copper.

According to the resistivity of copper and aluminum wires:

1.At the same temperature, the resistivity of copper wire is 0.0175 Ω, while the resistivity of aluminum wire is 0.0294 Ω. The shorter the length of the power cord, the lower the resistance, and the larger the cross-sectional area, the lower the resistance. For most conductors, there is also a certain relationship with temperature. The higher the temperature, the greater the resistance, but for a few conductors, the resistance decreases with increasing temperature.

2. Local damage to the cable sheath can cause slow damage to the insulation performance after water ingress, resulting in a gradual decrease in insulation resistance and overheating during cable operation.

During installation, the cables are arranged too densely, resulting in poor ventilation and heat dissipation.

4. The cable is too close to other heat sources, resulting in abnormal heat dissipation.

5. Poor joint manufacturing technology and loose crimping result in excessive contact resistance at the joint, leading to cable overheating.

6. Poor insulation performance between cables leads to low insulation resistance and overheating during operation.