Lightning protection measures during the installat

2022-08-08
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Lightning protection measures during the installation of petrochemical buildings

I. The setting range of lightning protection devices

if the overhead facilities such as tower cranes, external elevators, cross frames, gantry frames and high metal scaffolds that are higher than the buildings on the construction site are outside the protection scope of the lightning protection devices of adjacent buildings and structures, lightning protection devices should be set up in accordance with the regulations and checked frequently. If the lightning rod on the highest mechanical equipment has a protection range of 60, the crud of the air-cooled cooler should be regularly cleared and calculated to protect other equipment, and finally exit the site, other equipment can not be equipped with lightning protection devices

regulations on the installation of lightning protection devices for mechanical equipment in the construction site

II. Composition and technical requirements of lightning protection devices

the lightning protection device at the construction site is generally composed of lightning rod, grounding wire and grounding body. Lightning rods are installed on the top of tower cranes, people and goods elevators, steel scaffolds, etc. of tall buildings. The length of lightning rod (lightning arrester) on mechanical equipment shall be 1~2 meters; The grounding wire can be copper conductor with a cross-sectional area of not less than 16mm, or copper conductor with a cross-sectional area of not less than 12mm, or round steel with a diameter of not less than ∮ 8, or the metal structure of the equipment, but the electrical connection should be ensured; There are two kinds of grounding bodies: bar shaped and strip shaped. The rod-shaped grounding body generally adopts steel pipe with length of 1.5m and wall thickness of no less than 2.5m or angle steel of 5*50. One end of it is vertically driven into the ground, and its top is not less than 50cm from the ground. The strip-shaped grounding body can be flat steel with a cross-sectional area of not less than 50mm and a length of not less than 3m, lying flat 500mm underground. The lightning rod, grounding wire and grounding body of lightning protection device must be welded (double-sided welding), and the weld length should be 6 times the diameter of round steel or more than 2 times the thickness of flat steel. The impulse grounding resistance of all lightning protection devices on the construction site shall not be greater than 10

lightning protection measures for various buildings should be taken to prevent direct lightning and lightning wave intrusion. Buildings can use the reinforcement in the foundation as the grounding body; Two main reinforcements on the inner and outer sides of the outer edge column can be used as lightning protection downlead; Especially when encountering some product problems, large metal objects such as railings, doors and windows on the external wall above 45m should be connected with the lightning protection device to prevent side lightning strikes; Lightning rod, lightning strip and lightning protection can be installed on the building

lightning protection measures for overhead lines should be equipped with lightning wires; For example, Beijing Chaoyang High Tech Research Institute improves the insulation level of the line itself; Use triangle top line as protective line; Install automatic reclosing device or self reclosing fuse

III. lightning protection measures for traffic and distribution substations

install lightning rods to protect the entire substation and distribution building (structure) from direct lightning; Valve type arrester or protective gap shall be installed on the high-voltage side. It is mainly used to protect the main transformer, so as to prevent the high potential from invading the experimental curve along the high-voltage line, which can locally enlarge the display substation and damage the substation, which is the most important equipment. Therefore, it is required that the lightning arrester or protection gap should be installed as close as possible to the transformer, and its grounding wire should be connected with the transformer's low-voltage neutral point and metal shell for grounding. The valve type arrester or protective gap installed on the low-voltage side is mainly used in the lightning area to prevent the lightning wave from penetrating the insulation of the transformer from the low-voltage side. When the neutral point on the low-voltage side of the transformer is not grounded, the neutral point should also be equipped with lightning arrester or protective gap

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