What is the difference between lightning protection network and lightning protection?
In fact, the lightning arrester is equivalent to the criss cross of the lightning belt, and the lightning protection network is installed on the building, so the lightning protection of the building can be carried out. There are two forms of lightning protection network, namely, bright and dark. The installed lightning protection network is on the roof of the building or on the top roof of the building, with the visible visible metal grid as the flash receiver, and the grounding of the lead line along or along the outer wall. As the installed lightning protection network is not very attractive, it will cause difficulties in construction, and will increase additional project investment, so it is now less used.
Lightning belt is strip body made of steel or flat steel, usually installed in the building vulnerable to direct lightning location, such as ridge and groove house (with a slope roof, roof and parapet edge) or flat roof. Lightning protection belt should maintain good electrical connection with the earth, when the thunder down first on these buildings guide vulnerable to lightning site development, the first lightning with lightning, lightning will withstand a direct, powerful lightning current into the earth, so that the buildings are protected. This is a kind of measure to protect the vulnerable parts of the building from lightning. It has been widely used in lightning protection of civil buildings and ancient buildings. The diameter of the round steel used to form a lightning conductor shall be no less than 8mm, and the cross section of the flat steel shall be no less than 48mm2, and the thickness shall be no less than 4mm. In order to protect the parts which are not vulnerable to lightning, the lightning conductor should be higher than the roof 0.2m, and the distance between the two parallel lightning arresters should be no more than 1Om. In the use of lightning belts for building lightning protection, if there is a chimney or other protrusions on the roof, there is also need to set another lightning rod or lightning belt to protect.
The use of steel skeleton in buildings (including reinforced floors and in the foundation, as long as you keep) the reliable electrical connection, is a large metal cage, and the earth has a good electrical connection, so that the whole building has become a reliable grounding equipotential body, constitute a large three-dimensional Faraday cage. All kinds of metal equipment, electrical equipment and upper and lower pipes which are placed in the building can be well prevented from direct lightning stroke as long as they are reliably connected with the steel bar. The use of existing bars as a lightning arrester saves investment and maintains the perfect shape of the building. Of course, the effect of lightning protection on cage lightning protection is related to the size of the cage and the size of the grid. The smaller the cage and the smaller the grid size, the better the lightning protection effect. The size of the grid depends on the importance of the protected buildings and should be determined by the lightning protection design code of the building.
