Lightning protection zone (LPZ) division
According to IEC1312-1 standard of protection against lightning electromagnetic pulse, lightning surge protection system is divided into four regions, it is divided as follows:
LPZ0A areas: cloud-to-function area, is the lightning rod system to protect areas outside the building area, because all the objects in this region are likely to suffer a direct lightning strike, and may lead to go all the lightning current; addition to all objects in this area are in lightning electromagnetic field the strongest place, it is the strongest for the induction of lightning.
LPZ0B areas: the role of lightning main area, the lightning rod system of protected areas in the building, but not space electromagnetic shielding effect of electromagnetic fields of lightning does not decay, in this space, objects can be used in conductive area induced a strong lightning current.
LPZ1 areas: building shield area, the object can not be subjected to cloud-to the region, flow to the conductor of the lightning current 0B area than the further reduction of the local electromagnetic field may also be attenuated, depending on the building shielding .
LPZ2 areas: room shielding area, which for the mainframe computer room space, shielding measures should be adopted to further reduce the electromagnetic field interference. When the metal wires (power lines, signal lines, etc.) across different conservation district, because of the role of electromagnetic induction, will result in higher over-voltage, affecting the safety of indoor equipment. Therefore, it needs to install the appropriate over-voltage protection, the equipment for protection. Protection in different partitions, using mine-level is different. At the same time, it needs to arrange appropriate Equipotential bonding.
The District at the area bonderay should be arranged appropriate lightning and surge protection. Usually, it needs surge protection. At the boundary LPZ0B to LPZ1, it needs to install Class I lightning arresters; at the boundary LPZ1 to LPZ2, it needs to install Class II surge arresters; at the boundary LPZ2 and equipment to be protected, it needs to install Class III surge protectors, or surge protector sockets. Its working principle is: by using sub-class surge protection device, to discharge and reduce lightning or over voltage step by step, then to protect the customer premise equipment effectively.