中文 
Five reasons for faults of medium voltage insulated cables
The structure of medium voltage insulated cable has three layers: conductor, insulation and external insulation. It is mainly used for power transmission and distribution. Next, Qingzhou cable manufacturer will summarize the five causes of high-voltage insulated cable failure.
Five reasons for faults of medium voltage insulated cables
During installation, the process construction or process regulations are not strictly followed, and potential problems are not considered. DC withstand voltage test is adopted for completion acceptance, resulting in the formation of reverse electric field in the joint, resulting in insulation damage.
Due to the inevitable defects in the material of the cable itself and in the process of cable manufacturing, laying and terminal production, the cable insulation will experience different degrees of aging due to the influence of electrothermal, chemical, environmental and other factors during operation, which will lead to cable failure.
Caused by improper sealing treatment. The intermediate joint adopts the sealing structure of metal copper shell plus PE or PVC insulation and anti-corrosion coating to ensure the tightness of lead seal during on-site construction and effectively ensure the joint sealing and joint waterproof performance.
During insulated cable construction, small slip marks will inevitably appear on the insulation surface. Semiconductor particles and sand particles in the abrasive cloth may also be embedded in the insulating layer. In addition, moisture will be absorbed in the insulation due to the exposure of the insulation to the air during the construction of the joint. These all leave hidden dangers for long-term overload operation.
The site conditions are relatively poor. When cables and connectors are manufactured in the factory, the environment and process requirements for cables and connectors are very high, and the temperature, humidity and dust on the construction site are difficult to control.
