There are two types of lightning protection lines, one is used for overhead power lines to protect power lines from lightning and to ensure the normal operation of overhead power lines; the other is used for lightning protection of high-rise buildings, that is, the highest in buildings. At the side of the roof, it is laid with galvanized steel bars with a diameter of not less than 8mm. The vertical distance of the steel bars from the building is not less than 100mm to prevent lightning strikes on the buildings.
The lightning protection grounding plan of a building usually indicates the composition and installation requirements of the lightning protection grounding system of the building, and is generally composed of a roof lightning protection plan and a basic ground plan.
In the construction of modern buildings, the metal reinforcement of the building is often used as the lightning protection down conductor. It has been proved that this method has many advantages. Because the lightning current flows into the steel bar and will be connected with the steel mesh through the beam, the floor, etc., although most of them are tied, they are basically connected to the net, and the lightning current can be dispersed to various parts, which becomes a good diffusing net, which is beneficial to the whole. The building is in an equipotential state, avoiding counterattacks between various parts of the building, thus increasing the safety factor. Using the main steel bar as the down conductor, people often worry about whether the lightning current will cause the steel bar to overheat and affect the strength of the steel bar. In fact, when the lightning current flows into the steel mesh, it will quickly disperse, and the current flowing through each part is not very Large (especially multi-column buildings), as for the main rebar of the column at the junction with the lightning receptor, due to the fact that multiple bars are connected in parallel by lashing or welding (the application has been considered in the construction), it is not due to temperature. Increase and affect the strength of the steel. This method has a low cost and good reliability, so it has been widely used.