What is the active lightning and how it differs from the usual
Lightning protection - is a set of technical solutions and devices that are used to ensure the safety and security of buildings and people. And most of you know that lightning - a set of passive elements: air terminal, and grounding conductors. But there are so-called active except the passive system. That's about it and discuss in this article in more detail.
What is the active lightning protection
So called active lightning protection electrical system, which serves for gravity and artificial lightning discharge to the grounding circuit. This system is only activated when the protected object around are real prerequisites for the formation of lightning. Activated system is running ahead of the curve and gives a lightning bolt on the natural channel.
At the same time, such a system protects a much larger area compared to conventional methods of protection.
How does the active lightning protection
In order to properly understand the principle of active lightning protection, let's say a few words about how the generated charge is a natural linear lightning.
Linear zipper is a none other than electric discharge in atmosphere, which is formed result of an increase of the electric field between the ground and the clouds or between various objects on the earth, and clouds.
Quite simply, Lightning - giant spark, which transfers the charge when the field reaches a critical level.
It formed such a discharge from the moment when it begins to form a descending stepped leader, at a time when by cloud towards the ground is formed by a luminous channel moving in jerks at an approximate rate of 28 to 280 meters per give me a sec.
After a little period of time to meet the leader, forward to the ground, the ground is already beginning to emerge upward leader (the way of the earth - clouds). And when the two leaders meet (form a common channel) there is a discharge of lightning.
When lightning hit the building, then repeatedly it increases the risk of electrical shock people in this building. In addition, the inevitable destruction of the building. And according to statistics, up to 40% of all fires occur due to lightning.
Any system generates lightning counter leader, which significantly increases the probability of lightning is in the air terminal. A difference between an active and passive system lies in the active air terminal in the active system.
Active lightning arrester reacts to increase the electric field intensity during approaching thunderstorm. It is from this voltage, which is induced in the antenna field devices, there is a capacitor charging. And when the voltage reaches a value to them in the 13-14 kV breakdown occurs in the switches, and the device generates voltage pulse which reaches 20 kV, and its polarity is opposite the polarity of the value of the lightning Front.
Artificially created momentum appears earlier than would have formed a natural upward leader. And this artificial upward leader extends for a considerable distance. Thus protecting a large area, literally making lightning strike is in lightning arrester, and nowhere more.
How to choose the right protection device
The choice of such active device depends on whether the object to be protected. It should consider the following factors:
1. The area to be protected from possible defeat by a lightning strike.
2. Expected and actual frequency of lightning strikes the protected object.
3. The location of the protected object. For example, if the protected structure standing in an open field, the probability that it will hit the lightning is much higher than if it was in a densely built-up city block.
4. Taking into account the likely effects after a direct lightning strike into the protected object.
Only taking account of all these factors, you can proceed to the election of the active air terminal with appropriate characteristics.
conclusion
That's all I wanted to tell you about the active lightning protection. Like this, then vote it Like. Thank you for your attention!