How do Category II lightning protection buildings prevent surge intrusion?
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Why does the Code for Design of Lightning Protection of Buildings GB50057-2010 specify how to prevent surge intrusion only for Category 1 lightning protection buildings, while no such provisions are given for Categories 2 and 3? 4.1.1 The mandatory provisions clearly state that all lightning protection buildings must be protected against the intrusion of lightning surges.
There are regulations regarding surge currents, as well as the required spacing between wires and down conductors
Thank you. Are there no requirements regarding whether the incoming line should be overhead or buried?
Regarding overhead lines, one can refer to the relevant provisions in GB50064; generally, overhead feeders are rarely used in low-voltage systems. Whether overhead or buried, the lightning current is discharged through surge protectors (50064 is a MOV). The difference lies in the issues of location, quantity, and device capacity determined according to the circumstances
Thank you. I have a question that I couldn’t find online: what does the voltage protection level of a surge protector mean? For example, if the voltage protection level is 2.5 KV, does it mean that the protector can no longer provide protection if the actual voltage reaches 3 KV?
The protection level of 2.5 kV means that with this level of surge protection, the surge voltage can be limited to 2.5 kV, thereby preventing damage to the equipment connected downstream, provided that such equipment is capable of withstanding a surge voltage of 2.5 kV.