China has a vast territory and complex terrain. Mountains account for about 33% of the country's total area, and plateaus account for about 26%. When electrical equipment is installed in an area above 2,000 meters, the requirements for the safe operation of the equipment are much higher than in plain areas. As an important safety component, lightning arrester should be selected as the altitude increases to ensure the safe operation of power equipment? This is also a concern for plateau users.

The climatic characteristics of high-altitude areas make the free travel of free electrons in high-altitude areas longer than in low-altitude areas. The initial impact energy obtained by electrons during impact is greater. Even under the action of a lower electric field, it is easier to generate free electrons. The self-sustained discharge generates an electric arc.

Therefore, the SPD used in high altitude areas must meet the creepage distance of each part of the component> the creepage distance limit of its environment and altitude. Otherwise, due to insufficient creepage distance, arcs will be drawn between different conductive metal parts of the lightning arrester, resulting in an arc short circuit, which will affect the normal operation of the equipment.

According to the standard (GB1802.1), surge protectors are generally used by manufacturers whose altitude does not exceed 2000 meters, and those whose altitude exceeds 2000 meters should be negotiated. Under standard atmospheric pressure (H≤2000m), the electrical clearance and creepage distance between live parts and the ground should not be less than the values specified in Table 14 and Table 15 of GB18802.1-2011: SPD usually uses solid materials and air as the insulating medium . As the altitude increases, SPD should increase the electrical clearance and creepage distance. The electrical clearance should be determined by multiplying the value specified in the conventional product standard by the corresponding altitude correction factor. The altitude correction factor is calculated according to the correction value specified in GB/T20626.1 or IEC60664-1:2007.