The structure of the lightning rod

The lightning rod is composed of three parts: the air-termination device, the grounding down-conductor and the grounding body. The air-termination device is generally made of round steel or steel pipe with a diameter of 15 to 20 mm and a length of 1 to 2 m. In thunderstorm weather, when energized clouds occur in the sky of high-rise buildings, a large amount of electric charge is induced on the lightning rod and the top of the high-rise building. Because the tip of the lightning rod is pointed, the tip of the conductor always accumulates the most electric charge during electrostatic induction. That way, the lightning rod collects most of the charge. The lightning rod forms a capacitor with these charged clouds, because it is sharp, that is, the area facing the two poles of the capacitor is very small, and the capacitance is very small, in other words, it can hold very little charge. And it accumulates most of the charge, so when there are more charges on the cloud layer, the gas between the lightning rod and the cloud layer is easily broken down and becomes a conductor. In that way, the charged cloud layer and the lightning rod create a channel, and the lightning rod is also grounded. The lightning rod can guide the charge on the cloud layer into the ground, so that it does not pose a risk to the multi-storey building and ensures its safety. The charged cloud first operates from top to bottom. When a lightning rod is installed at a high place, the electricity between the clouds will be drained first, and then when the house touches the cloud, there is basically no or only a small amount of electricity and there is no danger. . Lightning rods and lightning wires are generally used for protection against direct lightning strikes. Lightning rods and lightning conductors are actually a set of lightning conductors, which can lead lightning strikes to themselves and leak to the ground, thereby protecting other equipment from lightning strikes. Lightning rods are generally used to maintain equipment in power stations and substations. Lightning conductors are mainly used to maintain power lines, and can also be used to maintain equipment in power stations and substations. The lightning rod consists of three parts: the air-termination device, the grounding lead and the grounding body. (1) Air Termination. The lightning receptor is located at the upper end of the lightning rod. It must be higher than the equipment to be protected. The top is tapered and is the largest part of the lightning rod. The air-termination device is usually made of galvanized round steel or galvanized pipe with a length of 1-2m. (2) Ground down lead. The grounding down-conductor is the connecting wire between the air-termination device and the grounding body. It is used to safely introduce the lightning current on the air-termination device into the grounding body. It is generally made of galvanized round steel with a diameter of not less than 8mm or galvanized steel strand with a cross-section of not less than 35mm². It can also be made of flat steel with a thickness of not less than 4mm and a total width of not less than 12mm. Concrete structures can also be used. The steel bar in the tower pole or the steel tower itself is used as the down conductor. (3) Grounding body. The grounding body is the lower end part of the lightning rod, which is a group of conductors laid on the ground. Its function is to reduce the resistance between the lightning rod and the ground to reduce the amplitude of the lightning impulse voltage. The grounding body is generally driven into the destination by a plurality of angle iron, flat steel or round steel pipes, and the grounding resistance of the grounding body cannot exceed the specified value.


Post time: Jul-09-2022