Cable is an important medium of power transmission, In the use of the cable, often occurs the variety of failures.
Cable lines common faults are mechanical damage, insulation damage, insulation dampness, insulation deterioration, over-voltage, cable overheating and so on. When the above fault occurs, it should cut off the power of the faulty cable to find the point of failure, the fault inspection and analysis, and do repair and test until the fault is eliminated before resuming power supply.
The most direct reason for cable failure is the breakdown of insulation.
The main reasons for cable failure are:
A: Overload operation: long-term overload operation, will make the cable temperature rise, insulation aging, resulting in breakdown insulation and reduce construction quality;
B: Electrical aspects: cable head construction technology failed to meet the requirements of cable head sealing, moisture intrusion inside the cable, cable insulation performance degradation; laying cable did not take protective measures, the protective layer is damaged, reducing the performance of insulation;
C: Civil engineering aspects: poor of ditch drainage, water immersion cables for a long time, damaging the dielectric strength; The well is too small, cable bending radius is not enough, long-term by the extrusion of external damage. Mainly municipal construction machinery unreasonable construction, digging and cut off the cable;
D: Corrosion: the protective layer has long been exposed to chemical corrosion or cable corrosion, resulting in failure of the protective layer, reducing the performance of insulation;
E: The cable itself or the cable head accessories poor quality, poor sealing of the cable head, insulating glue dissolved, cracking, resulting in line disconnection fault.