Sometimes the cable will have some faults during the working process, causing some problems, so we need to understand the cause of the fault, which can prevent and prevent the fault from happening. Let's take a look below.

1. Overload operation: Long-term overload operation will increase the temperature of the cable and cause the insulation to age, thereby breaking down the insulation and reducing the construction quality.

2. Electrical aspects: the construction process of the cable head does not meet the requirements, the sealing performance of the cable head is poor, the moisture penetrates into the inside of the cable, and the insulation performance of the cable decreases; no protective measures are taken when laying the cable, which damages the protective layer and reduces the insulation.

3. Civil engineering includes: poor drainage of well pipe trench, long-term immersion of cable in water, damage to insulation strength; too small well, insufficient bending radius of cable, long-term damage from external extrusion force. It is mainly mechanical brutal construction and excavation of cables in municipal construction.

4. Corrosion: The protective layer has been subjected to chemical corrosion or cable corrosion for a long time, resulting in the failure of the protective layer and the reduction of insulation.

5. The quality of the cable itself or the accessories of the cable head is poor, the sealing of the cable head is poor, the insulating glue is dissolved and cracked, and the resonance phenomenon is the line disconnection fault, which forms a resonance circuit of the ground capacitor and the excitation inductance of the distribution transformer, and stimulates the ferromagnetic resonance.