Lightning disasters are one of the ten most serious natural disasters. Although lightning strikes are a small probability event, they are 100% disasters for people or buildings struck by lightning. In order to reduce and avoid disasters caused by lightning, Modern mankind invented the lightning rod.
So, how does a lightning rod protect against lightning?
in fact, the lightning rod itself is a lightning rod, which is composed of an air-termination device, a down conductor and a grounding body. Because it is higher than the building itself, the lightning generally strikes the lightning rod first, and the large current of the lightning is led to the earth through the conductor connected to the ground through the down conductor to protect the surrounding environment.
After installing a lightning rod, will you no longer be afraid of lightning?
Lightning rods cannot protect buildings 100%.
Because the down conductor itself is a thunder and lightning channel, the strong current passing through the down conductor will also generate strong electromagnetic radiation. This electromagnetic radiation will still affect the electronic equipment in the building, not to say it is installed. Lightning rods are safe in this building. Surge protectors must be installed for some electronic devices to prevent induced lightning damage. It is impossible for a lightning rod to protect the building itself 100%, and the phenomenon of lightning bypassing the lightning rod and hitting the building will still occur. It is just that the probability of hitting the lightning rod is higher, and the probability of hitting the building is reduced.
In addition, the protective effect of lightning rods is selective and can only prevent direct lightning strikes, but cannot do anything against induced lightning.
The lightning protection system includes two parts: external lightning protection and internal lightning protection.
01 External lightning protection
The main protection of external lightning protection is direct lightning strikes, which are composed of lightning rods, lightning protection belts, down conductors, grounding devices, etc., mainly to protect buildings from direct lightning strikes, fires and personal safety accidents.
02 Internal lightning protection
The internal lightning protection system mainly protects against indirect lightning strikes. It prevents lightning induction and lightning wave intrusion through shielding, equipotential connection, installation of surge protectors, and reasonable wiring. The focus is on protecting equipment and personal safety.
Therefore, although there are all kinds of lightning rods and other lightning protection equipment on the top of buildings in cities, they should not be completely superstitious about their role, because currently humans have not fully grasped the laws of lightning and cannot determine the whereabouts of lightning.