How does a lightning rod work?

The lightning rod is one thing we are all familiar with. It is often installed on the top of the protected object to protect buildings, tall trees and so on. Although we are familiar with the name of the lightning rod, we probably know its importance, but do you know the principle of the lightning rod? What are its usage scenarios? Let's take a closer look at it.

1.Definition of lightning rod

Lightning rods are devices used to protect buildings, tall trees, etc. from lightning strikes. Install a lightning receptor on the top of the protected object and connect it to the underground grounding net with a wire that meets the specifications. The lightning rod specifications must comply with the GB standard, and the lightning rod height specifications required for each lightning protection category are different.

It distorts the ground electric field when the thundercloud discharges close to the ground. At the top of the lightning rod, a space for local electric field concentration is formed to influence the development direction of the lightning pilot discharge, guide the lightning discharge to the lightning rod, and then introduce the lightning current into the earth through the grounding down conductor and the grounding device, thereby protecting the protected object from lightning strikes. .

2、Principle of lightning rod

Let us understand the principle of the lightning rod. Thunderbolt and tall buildings in the thunderstorms, when there are charged clouds over tall buildings.

The top is sensed by a large amount of charge, because the lightning rod needle is pointed, and when electrostatically induced, the tip of the conductor always accumulates the most charge. In this way, the lightning rod collects most of the charge. The lightning rods in turn form a capacitor with these charged clouds. Because of its sharpness, the two plates of this capacitor have a small opposing area and a small capacitance, that is, it can hold a small amount of charge. And it accumulates most of the charge, so when there is more charge on the cloud, the air between the lightning rod and the cloud is easily broken down and becomes a conductor. In this way, the charged cloud layer forms a path with the lightning rod, and the lightning rod is grounded again. The lightning rod can push the charge on the cloud to the ground, making it dangerous to high-rise buildings and ensuring its safety.

3. The use of lightning rods

In thunderstorms, we sometimes see some towering trees being knocked down by lightning, and some high-rise buildings such as towers and high-rise buildings are safe and sound. What is the reason for this? These towering trees are also exposed to a large amount of electric charge due to the induction of clouds with a large amount of electric charge. When the accumulated electric charge is too much, the tree is knocked down. Under the same conditions, the high-rise buildings are safe and sound, thanks to the lightning rod.

In addition to tall buildings, lightning rods are frequently used in various shops, mines, and petrochemicals.