1. External damage. For example: substandard cable laying construction is easy to cause mechanical damage, and in civil construction, it is easy to operate underground cables such as cable damage. Sometimes if the damage is not serious, it may take months or even years to cause a complete breakdown of the damaged part, and sometimes serious damage may cause a short-circuit failure, which directly affects the safe production of the electrical unit.
2. Moisture insulation. For example: cable joints are not qualified and joints in humid climates, joints can make water or water vapor, the formation of water trees mixed for a long time under the action of the electric field, the insulation strength gradually causes damage to the cable failure.
3. Chemical corrosion. In the area of acid-base interaction, the outer protective layer is often caused by armored cables, wires or corrosion protection layers that have suffered chemical or electrochemical corrosion for a long 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 the heating of the conductor. At the same time, the skin effect and the eddy current loss of the charge, and the dielectric loss of the steel armor can also generate additional heat, thus making the cable temperature .
5. The cable connector is faulty. The cable connector is the weakest link of the cable personnel due to frequent cable connector failures, and is directly negligent. In the manufacturing method of the cable joint by the construction worker, if the crimp connection is not tight and the heating is insufficient, the insulation of the cable head is reduced, causing an accident. Share from Jiangsu Far East Cable.
Therefore, we must make corresponding protective measures for the common faults of the above cables, so as to extend the service life of the cables.