How to install the lightning rod?

At present, it is a thunderstorm, and we sometimes see some towering trees knocked down by lightning, while some high-rise buildings such as towers and tall buildings around them are safe and sound. What is the reason?

These towering trees are induced by clouds with a lot of charges, and they also carry a lot of charges. When they accumulate too much charge, trees will be knocked down.

In the same situation, I'm afraid the lightning rod is responsible for the safety of high-rise buildings. In many towers, there is something made of metal, which looks like an embroidery needle. The needle stands upright. This is a lightning rod.

Then, why does this seemingly inconspicuous thing, which looks like an embroidery needle, have such a great effect and can also "lightning"? Actually, lightning rod should be called lightning rod.

Working principle of lightning rod

The whole working process of lightning rod is to attract lightning and then transmit it to the earth for absorption.

To complete this process, three things are needed-lightning receptor, down conductor and grounding body.

Therefore, the lightning rod attracts a certain range of lightning to itself, and then introduces it underground to prevent problems before they happen. The protection range of lightning rod is related to its height and size.

The lightning rod we talk about every day is a lightning receptor. In addition to lightning rods, there are lightning wires, lightning belts and lightning protection networks. The function of lightning arrester is to attract lightning.

When the lightning rod works, it is connected to the earth through the down lead and grounding body, so that the potential on the lightning rod is the same as the earth (the ground potential is extremely low). Because of the high height of lightning rod, its own potential is low. Lightning with extremely high potential is naturally attracted by lightning rods. After the lightning rod attracts lightning, the top potential rises and the current begins to flow to the earth.

Due to the large current generated by lightning, a strong electromagnetic field will be generated on the lightning rod, which will form a path between the lightning rod and lightning, and lightning will be continuously introduced into the earth.

The function of lightning rod

Installing lightning rod is an effective way to avoid lightning strike. A metal pole is erected at the highest part of the house, and the lower end of the pole is connected with a thick enough copper wire, and the lower end of the copper wire is connected with a metal plate, which is buried in a damp place deep underground. The upper end of the metal bar must be a sharp point or bifurcate into several sharp points. With such a device, when charged clouds appear in the sky. The tip of lightning rod concentrates different charges due to electrostatic induction, resulting in tip discharge, which is in harmony with the electricity in the cloud and avoids violent lightning strike. This is one aspect of lightning rod lightning protection. However, this effect is quite slow. If the cloud accumulates electricity quickly, or a cloud with a lot of charge suddenly flies, sometimes it is too late to neutralize it in the above way, so there is a strong discharge, and lightning will still happen. But at this time, because the lightning rod is higher than the surrounding objects, the tip of the lightning rod concentrates charges with different symbols from those in the cloud. If lightning occurs between clouds and ground objects, the discharge current mainly flows into the earth through the lightning rod, so it will not hit the house or nearby people, but only the lightning rod.

It can be seen that the discharge at the tip of lightning rod will reduce the possibility of lightning between ground objects and clouds; Inevitably, the house and people are safe when they are hit by lightning. Due to the structure and function of lightning rod, special attention should be paid to maintaining good conductivity of lightning rod. Once there is a bad connection or a broken connection, the part above the crack becomes an isolated conductive system. When there is charge in the cloud, the upper part of the separation part induces the charge with the same sign as that in the cloud, and the lower part induces the charge with the same sign as that in the cloud. If the upper part and clouds discharge, the strong discharge current can only release a lot of heat through the building, thus causing lightning strikes. This can not only prevent lightning strikes, but also bring lightning disasters.

In order to prevent accidents, it is best to erect several lightning rods in tall buildings. In addition, each lightning rod can only protect a building area. For larger buildings, it is necessary to erect several lightning rods.