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Precautions for lightning rods and lightning protection belts
- 2019-08-08-

Precautions for lightning rods and lightning protection belts
(1)Lightning rods are protected from various antennas that are not far enough. Some electronic equipment such as radar, satellite, and communication equipment are connected to the top of the building, which is higher than the lightning protection belt that protects the building. When necessary, it is necessary to set up a lightning rod at a certain height. However, people often overlook the distance between the lightning rod and the antenna of the protected device. In fact, even if it is not a truly independent lightning rod, it needs to be separated from the protected antennas of various devices, such as more than 3 meters. This is because the lightning rod is a lightning receptor, and it may receive thousands of amps of lightning current of hundreds of thousands of amps. A powerful lightning current will generate strong electromagnetic pulses around it. It has a great impact on the antenna antennas that are too close. Therefore, the receiving device is reported. The lightning rod should be welded to the lightning protection belt in two directions, and the antenna base of the metal should be welded to the threaded steel in the beam that receives the antenna component of the antenna when manufacturing the antenna support of the device. In order to achieve the intention of grounding, that is, although the lightning rod and the antenna base may be connected to the same grounding device, it is also necessary to prevent the lightning rod from directly connecting to the antenna base on the roof. In both cases, the lightning current intercepted by the lightning rod has a very different impact on the equipment antenna, and multiple shunts may have been realized in the middle. (2) When the lightning rod is selected from steel pipes, the steel pipes are not thick. Some manufacturers use stainless steel pipes for decoration in order to reduce the weight of the lightning receptors. The wall thickness is only a few tenths of a millimeter and the cross-sectional area is far. Far less than the 50 mm' of the IEC rules, it can not withstand the impact of the powerful mechanical and thermal effects of direct lightning strikes. It is an authentic attitude. Once it is struck by lightning, it will be completely destroyed. For the same reason, some roofs should be beautiful. The stainless steel railings combine the effect of the parapet wall and the lightning protection belt, and it is necessary to ensure the thickness and cross-sectional area of the stainless steel tube. (3) The lightning protection belt partially collapses. It is often the case that some of the lightning protection belts fall due to roof repairs and the like. It is not as easy to attract attention as the lightning protection belt is disconnected. It should be noted that the view of the corrosion condition of the lightning receptor or the down conductor is different from the inspection of the rust condition. If the cross-sectional area of the rusty lightning receptor or the down conductor is not significantly reduced, its dispersion The streaming function is still there. It only affects the service life. Such conditions should not be easily judged as unqualified, but should be treated as required. For lightning protection belts and lightning protection nets made of galvanized materials, it is required to be welded in addition to the connection with the down conductor. Other places should use the special lightning protection belt dovetail support card to clamp the lightning protection belt. Both lightning protection belts and supporting steel bars are used for welding. To reduce the damage of the galvanized layer.
There are often many protrusions on the top of the building, such as metal flagpoles, loose tubes, steel ladders, metal chimneys, advertising frames, wind windows, etc., should be checked whether they are welded with lightning protection nets. Integral, the larger metal components should be welded to the lightning protection belt in two or more places. What is easy to lose is the cast iron discharge pipe (venting hole) that leads to the bathroom, and often forgets to connect it to the equipotential of the lightning protection belt. When a non-metallic roof can be removed from the space required for lightning protection, the metal parts of the roof structure below it should be regarded as qualified natural lightning receptors. This condition is often seen when viewing simple product warehouses. Will encounter, should not be forced to make a special lightning receptor on the roof, just put these metal beams as required and grounded