There are three main reasons for cable grounding fault.

First, the cable manufacturing defects, for unqualified products;

Second, the operating environment is bad, natural aging, and under external damage; Third, the installation is not standard, wiring rough.

The root cause of the grounding fault is only one insulating material---cable. China's large-scale terrestrial power stations are generally in the West, these places are generally desert, saline and alkaline land and daytime temperature difference, rodent is also more serious, the environment will be very humid. The cable trench is buried in the laying, and the requirements for filling and digging are higher; Distributed power station cable operating environment is not better than the above ground, the cable will withstand very high temperature, there are technicians to measure and control, roof temperature can even reach 100-110 ℃ high temperature, cable fire retardant requirements, and high temperature on the insulation breakdown voltage of the cable has a great impact.

Therefore, the selection design should consider the following points:

1. Insulation property of Cable

2, the cable moisture, cold and weather resistance

3. Heat-resistant and flame retardant of cable

4. Cable Laying mode

5, cable conductor material (copper core, aluminum alloy core, aluminum core) 6. Sectional specification of Cable