With the development of electricity, there are more and more aspects of relying on electricity in life, and the importance of wire and cable is also highlighted.
We know that wire and cable are used for power transmission.
If the wire and cable continue to heat up during operation, the temperature of the wire and cable will be too high.
If it is short, it will cause a short circuit trip, and heavy will cause fire, so use wire and cable.
Special care must be taken when heat is generated during operation.
The following are the six major factors that lead to the heating of the power cable during operation.
1 The cable conductor resistance does not meet the requirements, forming a hot scene of the cable during operation.
2 The cable selection type is improper.
The conductor cross section of the formed cable is too small, and the overload phenomenon occurs during operation.
After long-term use, the cable's heat and heat dissipation are unbalanced to form a fever scene.
3 When the cable device is placed too densely, the ventilation and heat dissipation effect is not good, or the cable is too close to other heat sources, which affects the normal heat dissipation of the cable, and may also form a hot phenomenon in the operation of the cable.
4 The joint manufacturing skills are not good, the crimping is not tight, the contact resistance at the joint is too large, and it will also form a cable episode fever.
5 The cable phase insulation function is not good, the formation of insulation resistance is small, and the operation will also have a fever scene.
6 The partial sheath of the armored cable is damaged.
After the water enters, the insulation function is slowly destructive, and the insulation resistance is gradually reduced, which will also form a fever phenomenon during the operation of the cable.
After the power cable has a fever scene, if the fault is not found, the cable will continue to be connected to the power supply and the insulation heat breakdown will occur.
The formation of a cable attack phase-to-phase short-circuit trip scene, severe may lead to a fire.
When the power cable passes a certain load current, it will definitely heat up. With the increase of the load current, the temperature of the cable surface will be higher.
If it is not processed in time, the result can be imagined.
For example, a polyvinyl chloride (PVC) cable is considered to have a core temperature of 70 degrees, and a surface temperature is 5 to 10 degrees lower.
Therefore, the cable surface temperature is basically safe below 60 degrees, thinking from the power supply protection, of course, the lower the temperature, the better.