Why do lightning protection facilities carry out annual inspections?
Browse times:1023 Release time:2018-4-19
In recent years, lightning disasters have become one of the more serious natural disasters. Some people think that thunderstorms are a small probability event and there is no need to test lightning protection devices every year. However, the performance of lightning protection devices is directly related to lightning protection.
Mentioned lightning protection devices, people naturally think of lightning rods. In fact, from the perspective of lightning protection technology, modern lightning protection facilities include external lightning protection (direct lightning protection of buildings or facilities) and internal lightning protection (protection of lightning electromagnetic pulses). The external lightning protection system is mainly In order to protect the building itself from fire accidents and personal safety accidents caused by direct lightning strikes, the internal lightning protection system is designed to prevent the intrusion of lightning waves, lightning overvoltage, and system operation overvoltage intrusion into equipment.
The external lightning protection device is commonly referred to as direct lightning protection technology, with lightning rods, lightning protection strips, lightning protection nets, and lightning protection cables. The lightning rods are the most common direct lightning protection devices. When the thundercloud discharge is close to the ground, it distorts the ground electric field. At the top of the lightning rod, it forms a space where local electric field intensity concentrates to affect the development direction of the lightning lead discharge, guide the lightning discharge to the lightning rod, and then through the ground down conductor and Grounding devices introduce lightning currents to the earth so that protected objects are protected from lightning strikes.
Isn't it easy to install a lightning protection device?
First of all, let's look at the structure of the lightning rod. The lightning rod is mainly composed of three parts: a lightning arrester, a down conductor, and a grounding device. The three should be connected well and the grounding resistance meets the requirements to achieve protection.
The role of thunder. Although the lightning rod was given the word “l(fā)ightning protection”, it simply meant that it could protect the protected object from lightning strikes, but in fact it was the opposite. It was the “upper body” of the lightning, and it was exposed to the thunderstorms of the year. Natural performance is also well-tested; in addition to the severe cold and heat of the wind, sun, rain, and frost all year round, as well as corrosion and decay, it often leads to its breakage, corrosion, severe corrosion, poor contact, and even the connection between the three parts. The situation of interruption occurs. Such a lightning protection device can not only prevent lightning, but also increase the potential danger of lightning damage.
Secondly, in the course of maintenance, renovation, and decoration of buildings, some units and construction workers do not pay attention to protecting their lightning protection belts (nets), resulting in human damage, and some accidentally cut off the grounding device during construction to cause breakage of the down conductor. And so on, it will bring about mine safety hazards.
Third, some units have a weak awareness of lightning protection, and they do not understand the performance of lightning protection devices, and randomly pull and erode other electrical circuits on lightning protection devices. These electrical circuits are often the "culprit" of lightning induced by various electronic devices in the building.
In addition, the internal lightning protection measures of buildings are mainly used for lightning protection devices for various kinds of electronic and electrical equipment against lightning induction. Because the materials used are mainly zinc oxide varistor elements and other electronic components, these lightning protection devices are suffering from After one or more repeated induced lightning strikes, its performance is significantly reduced or deteriorated, so regular inspections must also be carried out to detect problems that can be promptly repaired or replaced.
Some flammable and explosive places such as petroleum and chemical industries, and densely populated public places such as computer systems and schools of financial institutions, enterprises and institutions shall regularly employ professional organizations with testing qualifications to conduct tests to ensure the normal use of lightning protection devices. Take preventive measures.