The following key factors need to be considered when selecting a power lightning arrester:
Types and parameters of lightning arresters: Power lightning arresters are mainly divided into products that withstand 10/350μs waves and 8/20μs waves. 10/350μs wave products simulate direct lightning waveforms and are suitable for places with high potential, high voltage and high current, such as LPZ areas; while 8/20μs wave products simulate induced lightning waveforms and are suitable for indoor or main power switch locations, such as PZ1 areas. Key parameters include maximum discharge current Imax, maximum continuous withstand voltage Uc (rms) and residual voltage Ur. Maximum discharge current refers to the maximum discharge current that the lightning arrester can withstand, maximum continuous withstand voltage refers to the voltage at which the lightning arrester can continue to work without affecting its performance, and residual voltage is the output voltage value at the rated discharge current.
Classification of lightning arresters: Power lightning arresters are divided according to discharge current. Products that withstand 10/350μs waves include air gap type and switch type, while products that withstand 8/20μs waves often use varistors. According to the protection method, there are single-chip and combined types. The single-chip type can freely combine different numbers and types of lightning arresters according to the grid wiring method, and the combined type combines various modules into a set for easy wiring. According to the appearance structure, there are modular and box types. The box type is suitable for occasions where space is insufficient.
Installation method and environmental factors: The common installation method is 35mm rail installation, and some companies also use screws to fix. When choosing a lightning arrester, it is necessary to consider the local thunderstorm intensity, environmental factors, and the tolerance level of the protected equipment. In addition, different grounding systems (such as TT, TN, and IT systems) also affect the selection of lightning arresters. Improper selection can easily cause damage to the lightning arrester.
Other considerations: When selecting a lightning arrester, its heat resistance and thermal stability must also be considered. The national standard has specific requirements for the heat resistance and thermal stability of lightning arresters. In addition, the response time of the lightning arrester should be as short as possible so that it can play a protective role in time when lightning strikes.