1、External damage
For example, the construction of a cable installation is unqualified, and it is easy to cause mechanical damage. In civil construction, it is also easy to use underground cables for cable damage. Sometimes if the damage is not serious, it may take months or even years to cause the damage to completely break down the fault, sometimes seriously damaging the short-circuit fault that may directly affect the safe production of the electrical unit.
2、Insulation damp
For example: cable joints are not qualified and joints in wet climates, joints can make water or water vapor, under the action of electric field for a long time, r ground water trees are mixed, and the insulation strength gradually causes damage to the cable.
3、Chemical corrosion
In the acid-base interaction region, the outer protective layer is often caused by armored cables, wires or corrosion protective layers that have been subjected to chemical or electrochemical corrosion for a long period of time, resulting in poor insulation of the protective layer and cable failure.
4、Long-term overload operation
Overload operation, due to the current, the thermal effect of the load current through the cable will inevitably lead to heating in the conductor, while the skin effect and the eddy current loss of the charge, the dielectric loss of the steel armor can also generate additional heat, thus making the cable temperature .
5、Cable connector failure
The cable connector is the most weak link in the cable cable's personnel cable connector failure, which is directly negligent. In the manufacturing method of the cable joint of the construction worker, if the crimping is not tight, the heating is insufficient, resulting in a decrease in the insulation of the cable head, resulting in an accident.