For the four lightning protection areas of the building: direct lightning non-protection area, direct lightning protection area, first shielding protection area, second shielding protection area, and third shielding protection area, lightning arresters can be divided into three levels of protection.
1. Direct lightning strike non-protective zone (LPZ0A zone)：Refers to the area that is threatened by direct lightning strikes and has no attenuation of the lightning electromagnetic field. Various objects in the area are completely exposed outside the protection range of the lightning protection device, and are likely to be damaged by direct lightning and induction lightning. It can be simply understood as the exterior of a building with a lightning protection system installed.
2. Direct lightning protection zone (LPZ0B area)：There is only protection against direct lightning strikes but there is no attenuation area for lightning electromagnetic fields. PT cable connector. Because of the protection of a series of external lightning protection devices such as air-termination down conductors and grounding devices, the possibility of objects in this area being attacked by direct lightning is greatly reduced. However, there are no induction lightning protection measures in this area, and the equipment is vulnerable to induction attacks. This is the entrance damaged by lightning strikes.
3. A shielded protection zone（LPZone Z1): Located in the direct lightning protection area, it has the functions of electromagnetic shielding, boundary shunting and surge protector, etc., thereby suppressing the surge current. The lightning electromagnetic field in this area has been greatly attenuated. The main protection measures include electrostatic shielding, equipotential, lightning arrester protection, grounding, etc.
4. Subsequent lightning protection zone (LPZ1+n zone):In the direct lightning protection area, the electromagnetic wave is attenuated by a shielding protection area, and the lightning electromagnetic field is further attenuated due to equipotential bonding and SPD.
According to our division of lightning protection areas, lightning protectors can be divided into three levels of protection. How to choose a lightning arrester monitor? The first-level switching power supply SPD is generally used at the interface between the direct lightning protection zone and the first shielding protection zone. The surge protector is installed next to the main distribution box of the building as the first-level protection of the equipment; the second-level voltage-limiting power supply SPD with slightly lower energy should be used at the interface from the first shielding protection zone to the second shielding protection zone. Heat shrinkable cable accessories can be installed next to the distribution box as the second-level protection. Information system equipment is more sensitive to surges and electromagnetic interference, and a third-level power supply SPD should be installed next to the equipment for fine protection.
