The current carrying capacity of the Lightning Arrester is a very important performance indicator, which represents the maximum current energy that the Lightning Arrester can withstand under specified conditions.
In a physical sense, the current carrying capacity reflects the amount of current that the Lightning Arrester can withstand when absorbing overvoltage energy. When lightning or internal system operation generates overvoltage, a strong impact current will be formed in the circuit. The function of the Lightning Arrester is to introduce these overcurrents into the earth to protect electrical equipment from damage caused by excessive voltage. The current carrying capacity specifies the range of the Lightning Arrester's ability to safely handle such overcurrents.
For example, when struck by lightning, the lightning current may reach thousands of amperes or even higher in a short period of time. If the current carrying capacity of the Lightning Arrester is large enough, it can effectively discharge these lightning currents to the earth without losing its protection function due to overheating or other damage. If the current carrying capacity is insufficient, when the lightning current exceeds its tolerance range, the Lightning Arrester may be damaged and unable to work normally, causing the protected electrical equipment to be directly exposed to overvoltage, causing equipment failure.
The current carrying capacity is usually divided into lightning impulse current carrying capacity and operating impulse current carrying capacity. The lightning impulse current carrying capacity is mainly for lightning overvoltage conditions, which indicates the size of the lightning impulse current that the Lightning Arrester can withstand. The operating impulse current carrying capacity considers the overvoltage conditions generated by the internal operation of the system (such as switch operation, etc.), reflecting the ability of the Lightning Arrester to cope with the operating overcurrent.
Lightning Arrester with different current carrying capacity is suitable for different scenarios. In some areas prone to frequent lightning strikes, or for protecting important large electrical equipment (such as the main transformer of a substation), a Lightning Arrester with a higher current carrying capacity is required. For some small indoor electrical equipment or areas with relatively less lightning activity, the current carrying capacity requirements can be relatively low. Such a distinction helps to reasonably select the Lightning Arrester, while ensuring the safety of the equipment, and taking into account the cost and actual application environment.
