What is the second type of lightning protection building?
1. Lightning protection of buildings protected by state-level key cultural relics.
2. State-level halls, office buildings, large-scale exhibition buildings, large-scale railway stations, large-scale water supply pump rooms, and other particularly important buildings.
3. National-level computing centers, international communications hubs and other buildings that are of great significance to the national economy and are equipped with a large number of electronic devices.
4. Buildings that manufacture, use, or store explosive substances, and electric sparks do not cause explosions or cause great damage and personal injury.
5. Buildings with a dangerous explosion environment in zone 1, and electric sparks are not likely to cause explosions or cause great damage and personal injury.
6. Buildings with explosive atmospheres in Zone 2 or Zone 11
7. There is an open-air steel closed gas tank with explosion hazard in industrial enterprises.
8. Departments, provincial office buildings and other important or densely populated public buildings where the number of lightning strikes is expected to be greater than 0.06 times per year;
9. General residential buildings such as residential buildings and lightning protection office buildings where lightning strikes are expected to be greater than 0.3 times per year. The so-called zone 11 explosion hazardous environment refers to an environment in which the accumulated dust is occasionally raised to accidentally cause an explosive dust mixture. Buildings in explosive atmospheres in Zone 1 are those that cannot form under normal conditions but can form explosive mixtures in abnormal circumstances. Zone 2 explosion hazardous locations refer to the environment where explosive mixtures cannot normally occur, or even the presence of explosive mixtures that exist only for a short period of time.
A. Measures to prevent direct lightning: highlight the protection requirements for lightning protection of pipes, vent pipes, exhaust valves, and other pipes of dangerous gases, vapors, or dusts on the roof:
(1) The metal object may not be equipped with a lightning arrester, but it should be connected with the roof lightning protection device.
(2) Non-metallic objects outside the protective range of roofing grounding products should be equipped with a lightning arrester and connected to the roof lightning protection device.
B. Measures for lightning protection and lightning induction:
Anti-lightning measures should meet the following requirements:
1. The main metal objects such as equipment, pipelines, and structures in the building shall be connected to the protective grounding device for direct lightning protection or to the electrical equipment. The grounding device may not be provided.
2. Pipes, frames and cable metal sheaths laid in parallel shall be protected against lightning induced by the first type of buildings, but bridging may be avoided.
3. The connection between grounding mains and grounding devices for lightning protection in buildings shall not be less than two.
C. Measures against lightning induction: When the whole length of the low-voltage line is introduced with buried cables or cables laid in overhead metal trunking, the metal jacket and metal trunking of the cable should be grounded at the entry end; the height must be greater than 45m. Special provisions for Class II lightning protection structures: Reinforced-earth structures and steel-structure buildings with a height of more than 45m should be protected by the following measures for protection against dips and equipotentiality:
1. Steel structures and concrete reinforcements should be connected to each other.
2. The steel column or column steel should be used as the arrester line device to deflect the line.
3. Large metal objects such as railings, doors and windows, and lightning protection devices of 45m and above external walls should be connected.
4. The top and bottom ends of the vertically laid metal pipes and metal objects are connected with lightning protection devices.