GADA Electric tells you several ways of lightning hazard

- Aug 17, 2019-

The way lightning damage:

(1) Direct lightning damage

Lightning strikes directly on buildings and structures. The electromagnetic, thermal and mechanical effects of high voltage and high current can cause many hazards, such as collapse of houses, collapse of chimneys, forest fires, explosions in oil depots (explosives). Caused by aircraft accidents, outdoor human casualties, etc. The probability of direct lightning strike is small but the damage is great.

(2) electrostatic induction hazard

The powerful pulse current of Thundercloud lightning causes the charge in the cloud to neutralize the ground, causing a strong change in the electrostatic field, causing a charge on the nearby conductor that is opposite to the sign of the pilot channel, and the charge in the pilot channel during the main discharge of the thunderstorm cloud. Rapid neutralization, the induction of charge on the conductor is released, if not put into the ground, it will produce a high potential, causing fire damage to the equipment.

(3) Electromagnetic induction hazards

The lightning current varies from zero amperes to hundreds of thousands of amperes in the range of 50 to 100 μs, and then varies from several hundred thousand amperes to zero amperes, generating transient strong electromagnetic fields in the surrounding space, and being subjected to spatially varying electromagnetic fields. The protective material, whether it is a conductor or a non-conductor, acts as a cutting magnetic line to cause a high electromagnetic induction electromotive force to cause harm. At the same time, lightning can radiate from very low frequencies of a few hertz to ultra-high frequencies of several gigahertz, with electromagnetic radiation intensity of 5-10 kHz being the largest. When the protected object is close to lightning, it is mainly affected by static electricity. When it is far away from lightning, it is mainly affected by electromagnetic radiation. Light interference with signal lines, antennas, etc., and damage to equipment.

(4) Lightning wave intrusion hazard

After lightning strikes the power line, signal line, and metal pipe, it enters the room in the form of electric waves, endangering personal safety or damaging the equipment.

(5) spherical lightning hazard

A spherical lightning (ie, a spherical lightning) is an orange or red flame-like luminescent sphere, occasionally yellow, blue, or green. Most fireballs have a diameter of about 10 to 100 cm. The spherical mine usually rolls up and down at a speed of 1 to 2 m/s in the horizontal direction, sometimes 0.5 to 1 m from the ground, and sometimes rises 2 to 3 m. It can travel in the air for a few seconds to a few minutes. Spherical mines often enter the interior of a building's holes, chimneys, or open doors and windows, and sometimes enter the room through ungrounded windows and wires. The most common is to roll down the big tree into the building with a buzzing sound. Spherical mines sometimes explode naturally and sometimes explode when exposed to metal lines. Spherical mines are subject to flammable substances (such as wood, paper, clothing, bedding, etc.) causing combustion, and exploding gases or liquids can cause a greater explosion. Some spherical mines will disappear without leaving traces, but most of them are accompanied by explosions and loud noises. Occasionally, there is a smell of sulfur and ozone after the explosion. A spherical fireball can radiate a large amount of heat, so its burn power is greater than the destructive power.