International Electrotechnical Commission divide the building's lightning protection devices into external lightning protection devices and internal lightning protection devices. The external lightning protection device consists of three parts: the lightning receptor, the down conductor and the grounding device. The lightning receptor refers to the lightning rod, the lightning protection belt and the lightning protection net. It is located at the top of the building. Its function is to lead lightning or intercept lightning, that is, to draw the lightning current.
The down conductor is connected to the lightning receptor and connected to the grounding device. Its function is to lead the lightning current intercepted by the lightning receptor to the grounding device. The grounding device is located at a certain depth in the ground. Its function is to make the lightning current flow smoothly into the earth.
The function of the internal lightning protection device is to reduce the lightning current and electromagnetic effects generated in the building and to prevent secondary lightning such as counterattack, contact voltage and step voltage. Except for external lightning protection devices, all the facilities, means and measures used for this purpose are internal lightning protection devices, including equipotential bonding facilities, shielding facilities, installed lightning arresters, and reasonable wiring and good grounding. And other measures.