How to do lightning protection measures for light steel villas?
The principle of light steel villa lightning protection system:
According to the light weight of the light steel structure villa, the tall and heavy lightning rod is not suitable for installation on light steel houses and other buildings. Article 4.1.4 of the Code for Lightning Protection of Buildings (GB50057-94, 2000) gives four requirements for metal roofing as lightning protection lightning receptors for buildings (except for the first type of lightning protection buildings). This atlas is an atlas of architecture, with less contact with electrical designers, and the National Standard Atlas "Building Lightning Protection Installations" (99D501-2) and "Using Building Metal Body for Lightning and Grounding Installation" ( 03D501-3) There is no detailed practice of light steel structure roof lightning protection belt. In the current design, the basic steel bar is generally used as a natural grounding body, which is connected by 40X4 galvanized flat steel and subjected to total equipotential bonding.
1. Characteristics of light steel structure buildings
Light steel structure is a new building material. It uses H-shaped steel and thin-walled cold-formed C and Z-steel combination to build the skeleton of the house. The roof and wall are made of color-coated profiled steel or sandwich color plate, and gradually replace the traditional steel bar. Concrete building. Light steel structures use prefabricated components that do not allow for on-site drilling and welding. The main steel frame (beam, column) is welded steel or hot-rolled steel to fully exert the mechanical properties of high-strength steel. The secondary member (strip) is a high-strength, anti-corrosion-treated cold-formed thin-walled C- or Z-shaped steel that is bolted to the main steel frame.
The envelope system (wall, roof) of light steel structure buildings is divided into color steel profiled panels and color steel sandwich panels. Most of them are connected by self-tapping bolts and purlins (roof strips or wall rafters). The profiled steel plate is a building envelope plate which is formed by color-coated steel plate or galvanized steel plate and is formed by rolling cold bending. The heat preservation and heat insulation layer is a centrifugal ultra-fine glass wool cotton felt. The sandwich panel is a heat-insulating composite enclosure material obtained by combining a color-coated steel panel and a bottom plate with a heat-insulating core material by an adhesive (or foaming), and can be classified into a hard polyurethane according to the difference of the insulation core material. Sandwich panels, polystyrene sandwich panels, rock wool sandwich panels. Sandwich panels are generally factory prefabricated. The connection system of the enclosure system is generally a snap connection or a lap joint.
After the entire light steel villa house is connected to the foundation, the overall structure is a good lightning protection system. The traditional house needs to be galvanized lightning rod. The galvanized material of the light steel villa is a complete lightning protection system when it is closely connected with the ground. Light steel villas do not need to do special lightning protection measures. First, the metal casing can shield the internal electric field, which is a physical knowledge. Secondly, the entire light steel material is not exposed to the outdoors, and the outdoor decorative material is an insulating material and does not conduct electricity. If you are not at ease, install a lightning rod.
After the light steel villa is connected to the ground, the whole is a good lightning protection system. The traditional house needs to be galvanized lightning rod. The galvanized keel of the light steel villa is closely connected with the ground and is a complete lightning protection system. The shielding principle is Faraday cage.
What is a Faraday cage?
The outer casing of the Faraday cage is a metal or a good conductor. The outer casing is connected to the ground and has a discharge rod on the outside. The metal casing is an equipotential body, that is, the potential of each point of the casing is the same, no potential difference is generated, so there is no current, and the internal electric field is zero, which can shield and protect the inside. effect. Therefore, when the high voltage is passed, the internal personnel will not be injured. This device can be seen in almost every city's science and technology museum to spread the shielding principle to the public.
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