When a certain load current passes through the power cord, it will definitely generate heat.
As the load current increases, the temperature of the cable surface will be higher.
If it is not dealt with in time, the consequences can be imagined.
For example, polyvinyl chloride (PVC) cables are considered to have a core temperature of 70 degrees as an upper limit and a surface temperature of 5 to 10 degrees lower.
Therefore, the cable surface temperature is basically safe below 60 degrees.
From the perspective of power maintenance, the lower the temperature, the better.
The reasons why the cable heats up during operation are as follows:
1. The cable conductor resistance does not meet the requirements, causing the cable to heat up during operation.
2. Improper cable selection results in the conductor cross-section of the cable being used being too small, causing overload during operation.
After long-term use, the heating and heat dissipation of the cable are imbalanced, resulting in overheating.
3. The cables are arranged too densely during installation, resulting in poor ventilation and heat dissipation, or the cables are too close to other heat sources, which affects the normal heat dissipation of the cables and may also cause the cables to generate heat during operation.
4. The joint manufacturing process is not good, the crimping is not tight, and the contact resistance at the joint is too large, which may cause the cable to heat up.
5. The insulation performance between cable phases is not good, resulting in low insulation resistance and heating during operation.
6. Part of the sheath of the armored cable is damaged.
After water enters, the insulation performance will be slowly destroyed, causing the insulation resistance to gradually decrease, and it will also cause the cable to heat up during operation.
After the cable is heated, if no fault is found, the insulation will break down if power is continued.
This can cause a phase-to-phase short circuit in the cable to trip, potentially causing a fire.
Causes and solutions of heating of plug and power cord
Power cords can be seen everywhere in family life, and electrical appliances are basically inseparable from power cords, so this little power cord may despise him.
A water heater's heater plug is usually caused by a poor fit with the outlet.
Also take into consideration the normal phenomenon of fever.
It is normal if the surface temperature of the plug is lower than the ambient temperature plus 50 degrees Celsius.
If abnormal heating occurs, you need to consider replacing the socket or inspecting the plug socket.
1. Poor contact between the plug and the socket, coupled with the high load power, causes the plug to heat up. Such as electric kettle, electric iron, etc.
2. The new plug is loose internally, which is caused by rough production technology.
3. The old plug has been used for a long time and its insulation performance has deteriorated (or the plug has become loose).