Views:79 Author:Site Editor Publish Time: 2019-10-08 Origin:Site
We can usually see lightning rod. Some people think it is very safe after installing a lightning rod. In fact, there is no 100% lightning protection equipment. There is no lightning strike in the protection scope of lightning protection facilities, but the lightning energy is small. From an economic point of view, it will be very wasteful to achieve foolproofness. Therefore, the Code for Lightning Protection of Buildings and other standards only required to reduce the lightning strike.
First of all, the lightning rod is used to discharge the lightning current to the earth through the lightning conductor. If the lightning rod is installed, there is no regular inspection. If the lightning conductor is damaged and the grounding device cannot work normally, it will become a disaster. Therefore, the lightning protection device should be regularly tested.
Secondly, the lightning rod can only reduce the risk of direct lightning strikes on the building, but it does not protect the electrical equipment in the building. Why? Powerful lightning can cause electrostatic fields, magnetic fields to change, and electromagnetic radiation. In particular, the moment when lightning enters the lightning rod system on the building and releases the lightning current to the ground, it can also produce a rapidly changing electromagnetic field. The change time is extremely short, the voltage is very high, and even electric spark may be generated. However, the voltage resistance of electronic and electrical equipment, especially microelectronic equipment, is very low. Lightning not only interferes with the normal operation of radio communication and various equipment, but also may cause damage to many electrical equipment within a certain range, and even cause fire.
Therefore, the building must use all-round lightning protection technology to provide integrated lightning protection. We must not only do regular inspection and maintenance of outdoor lightning rods, grounding conductors and grounding devices, but also do the installation of indoor lightning arresters. Power lightning arresters, signal lightning arresters, telephone lightning arresters, network lightning arresters and many other lightning protection equipment can provide secondary protection for our indoor power supply, home appliances, network, telephone and other electrical equipment. Of course, when lightning is applied, it is also a good way to turn off electronic and electrical equipment.
Even though it is not 100% safe after installing lightning rod, it is important to ensure that the lightning rod can work well. In order to ensure that the lightning rod can perform well, here are six lightning rod setting principles.
1.There should be a distance of not less than 5 meters between the independent lightning rod and the protected object to avoid a counterattack when lightning strikes the lightning rod.
2.Lightning rods should not be installed on the high voltage distribution equipment frame of 35 kV and below, and the roof. The lightning rods mounted on the frame should be connected to the grounding grid and equipped with a centralized grounding device.
3.A lightning rod should not be installed on the door frame of the transformer.
4.The distance between the lightning rod and the grounding device and the road and its outlet should be more than 3 meters. Otherwise, gravel or 5~8 cm thick asphalt should be paved to protect the body from step voltage.
5.It is strictly forbidden to install overhead lighting lines, telephone lines, radio lines and antennas on lightning rods or frames.
6.If a light is installed on a separate lightning rod or frame, the power cord must be leaded or threaded into the steel tube and buried directly under the ground for more than 10 meters.