Everyone in the industry knows that lightning has great destructive power, and there are four main forms: direct lightning, lightning induction, lightning wave intrusion and ground voltage counterattack. Among them, induced lightning and voltage counterattack have the strongest destructive ability to weak current equipment. When lightning strikes in the sky, it will carry high-load lightning pulses, voltages and currents, which will be released irregularly in the form of electromagnetic waves, thus causing all wires with metals (such as antennas, CATV cables, communication cables, power supply system cables, etc.). ) In the lightning area of 1 ~ 5 km (depending on the intensity of lightning wave), the pulse voltage and current with corresponding intensity are instantly sensed, and these currents will follow all kinds of electrical equipment. The main reason is that all wires and cables connected to electrical appliances have different voltages, and high voltage will rush to low voltage to form current, thus partially damaging electrical equipment, causing paralysis of the whole equipment system, even damaging the whole machine and even touching personal safety in serious cases.

First, several lightning protection methods

1, direct lightning protection

For direct lightning, a lightning rod can be used, and its structure is shown in the figure: the lightning rod consists of three parts: the top is called the receiving end, the middle is the conductor, and the lower part is the grounding body. When the thunderstorm cloud is close to the lightning rod, it will induce a large number of different charges, which will be released into the air through the wire and the receiving end to neutralize the charges in the thunderstorm cloud and weaken the electric field intensity of the thunderstorm cloud, thus achieving the purpose of lightning protection. If the receiving end is direct lightning, the lightning rod can introduce lightning current into the earth, thus playing a protective role.

2, induction lightning protection

In order to prevent the damage of induced lightning to power supply lines, transmission cables, overhead antennas and high-rise conductive line buildings, silicon carbide valve arrester or metal oxide (such as zinc oxide) arrester can be installed on the lines, as shown in the figure; For high-rise buildings, the metal facilities in the building can be grounded together; For nonmetallic roofs, metal protective nets can be installed and reliably grounded. Although these measures are effective, sometimes lightning strikes are inevitable. The key reason lies in the existence of grounding resistance. Lightning strike electric grounding body flows through grounding resistance to generate high voltage, which can still damage the equipment, and the lightning protection effect is not ideal. Now with the progress of society, especially the rapid development of electronic technology, lightning protection technology is constantly improving and improving. There are more and more manufacturers of lightning arresters, and various types of new lightning arresters are constantly coming out. Equipotential arrester is one of them.

Second, although there are many lightning protection technologies in China at present, the principle is nothing more than three lightning protection methods.

First, the on-off arrester is disconnected, which can quickly disconnect the power supply and protect the equipment when lightning strikes. Advantages: simple engineering. Disadvantages: the lightning strike time is very short (calculated in nanoseconds), and sometimes it is too late to completely disconnect. Lightning pulse current has caused heavy damage to electrical equipment, and people are not allowed to cut off electrical equipment at will in today's life and work; Therefore, the shortcomings are very obvious, lightning protection can not be better, and the effect can be imagined. So it will be put into use gradually.

Second, the grounding arrester adopts the way of earth leakage. Principle: Lightning current is directly introduced into the earth to prevent electrical appliances from being struck by lightning, but a perfect underground project is needed. Advantages: Lightning can be completely discharged. Disadvantages: it will bring great construction inconvenience to residents of high-rise buildings, or it will be installed in places where the discharge is not ideal, such as mountains and loess. In this environment, the effect of releasing lightning is not ideal, and it will be corroded for a long time. No one will often check whether the ground wire is corroded, and sometimes the environment does not allow it. To reach the national standard (resistance ≤4 ohms), the cost of complete qualification is almost several times or even dozens of times the cost of arrester itself. If the ground wire is not well done, it will not play the role of lightning protection, and lightning will directly damage the equipment. It would be ideal if there is one that can solve the above shortcomings at the same time.

Thirdly, equipotential arrester.

Shenglei HL-20K lightning protection series is a new type of equipotential arrester developed and produced by our company according to the equipotential principle that the maintenance staff of high-voltage power transmission and transformation wear special work clothes with good conductivity and can work live on tens of thousands of volts arrester without being shocked.

1, the main advantages of equipotential arrester:

A, lightning protection effect has nothing to do with grounding. Because the arrester adopts the "equipotential" treatment technology, its lightning protection effect has nothing to do with whether the equipment is grounded or not, thus avoiding the trouble of grounding when installing the traditional arrester. Therefore, the installation is simple and the use is convenient.

Extend the service life of electrical equipment.

Grounding Although the electrical appliance is not damaged by lightning, the lightning pulse impacts the electrical appliance for a long time, which will damage the electrical performance of various components and affect the service life of TV sets, computers and other equipment. After the equipotential arrester is installed, the protection of electrical equipment should be faithful and reliable.

C, although small, the protective equipment is very capable.

Under the action of huge lightning current, the equipment or components of electrical appliances are heated and damaged. The heating energy is proportional to resistance, current and action time. Although the current is very large when lightning strikes, the lightning protection internal resistance is rarely used for a long time (8~20 microseconds) and the calorific value is very small, so it can protect the equipment and will not damage itself. In addition, because the lightning arrester is current-type, as long as it does not exceed the maximum current that the lightning arrester can withstand, it can withstand a very high lightning strike voltage, even if the lightning strike voltage is tens of thousands of volts or even higher.

D. power supply. Signal channel is lightning-proof at the same time, killing two birds with one stone, maintenance-free, flame-retardant and explosion-proof.

E, with the function of automatic diagnosis, modification and repair of internal faults.

F. Safety warning function: When the lightning arrester is completely damaged, it will not output any current to warn that it can no longer be used. This alarm function is not available in other lightning arresters.