Causes and consequences of power cable heating

Power cable through a certain load current, it will heat, with the load current increases, the higher the surface temperature of the cable, if not handled in time, the consequences can be imagined. Such as: polyvinyl chloride (PVC) cable, is the core temperature of 70 degrees for the upper limit, the surface temperature will be low to 5 ~ 10 degrees. Therefore, the cable surface temperature of 60 degrees below the basic security, from the power maintenance considerations, of course, the lower the temperature the better.
The reasons for the heating of the cable are as follows:
1, the cable conductor resistance does not meet the requirements, resulting in the operation of the cable fever.
2, cable selection is not appropriate, resulting in the use of the cable conductor section is too small, resulting in overload phenomenon, after a long period of use, the cable heat and heat imbalance caused by heat.
3, the arrangement of the cable is too dense, ventilation cooling effect is not good, or the cable is too close to other heat sources, affecting the normal heat dissipation of the cable, but also may cause the cable to produce heat in operation.
4, the joint manufacturing technology is not good, crimping is not tight, resulting in joint contact resistance is too large, it will cause the cable heating phenomenon.
5, the cable interphase insulation performance is not good, resulting in insulation resistance is small, the operation will produce heat.
6, armored cable partial sheath damage, after the water to the insulation performance caused by the slow destruction, resulting in the gradual reduction of insulation resistance, will also cause the cable running a fever.
After the heating phenomenon of the cable, if the cause is not found out in time, the cable will continue to run continuously, and the insulation thermal breakdown will occur. The occurrence of interphase short circuit tripping phenomenon, serious fire may cause.