Insulators are exposed to the atmosphere all the year round. Affected by lightning strikes, pollution, bird damage, ice and snow, high temperature, high cold, height difference and other factors, it will cause various accidents.
Lightning strike accident. Overhead line passages are usually hills, mountains, open areas and polluted industrial areas. Lines are extremely susceptible to lightning strikes causing insulator breakdown or bursting.
Bird damage accident. Studies have shown that a significant portion of insulator flashover accidents are caused by bird damage. In bird accidents, composite insulators are more likely to have flashover accidents than porcelain insulators and glass insulators. Insulator flashover accidents caused by bird damage mostly occur on transmission lines of 110 kV and above, and 35 kV and lower urban distribution networks have fewer flashover accidents due to bird damage. The reason is that there are relatively few birds in the urban area, the voltage of the line itself is not high, the air gap that can be broken is small, the insulator does not need to install a pressure equalizing ring, and the umbrella group can effectively prevent the occurrence of bird flashover accidents.