The Role Of Surge Protectors - Just Know This

When we look at the Baidu Encyclopedia of surge protectors, we can see the definition of surge protective device: "Surge protectors, also called lightning arresters, are electronic devices that provide safety protection for various electronic equipment, instruments, and communication lines." So we know that the role of surge protectors is: "Control the instantaneous overcurrent and voltage that suddenly rush into the wire loop and signal transmission line within the range that the equipment can withstand, or introduce strong lightning current into the earth to ensure that the equipment or system can work safely and stably without being damaged by impact." At the same time, this is also the main role of surge protectors.

The following is the classification of surge protectors. Because of their different flow rates, their functions are also different in details.

The role of a first-level surge protection device can discharge direct lightning current, or discharge the huge energy conducted when the power transmission line is directly struck by lightning. For places where direct lightning strikes may occur, CLASS-I lightning protection must be carried out. The main function of a first-level surge protector is discharge, and its lightning flow rate should not be less than 60KA, which is generally used for total power distribution.

The function of the secondary surge protector is to protect the residual voltage of the previous surge protector and the protection equipment of the induced lightning in the area. When the previous stage absorbs a large amount of lightning energy, there is still a part of the energy that is quite huge for the equipment or the third-level lightning protector, which needs to be further absorbed by the secondary surge protector. At the same time, the transmission line passing through the primary surge protector will also induce the lightning electromagnetic pulse radiation LEMP. When the line is long enough, the energy of the induced lightning becomes large enough, and the secondary surge protector is needed to further discharge the lightning energy. The main function of the secondary surge protector is to limit the voltage, and the lightning current capacity should not be less than 20KA. It is generally used for distribution cabinet lines.

The function of the third-level surge protector is to protect LEMP and the residual lightning energy passing through the secondary surge protector. It is generally used for terminal distribution equipment, and its lightning current capacity should not be less than 10KA. Different distribution

systems should choose corresponding surge protectors, which can be divided into TN (TN-S, TN-C, TN-C-S), IT, and TT.