Maximum protection against the negative effects of lightning strikes
Main essential principles of lightning protection consist iof forming one or more preferred attraction points for a direct lightning strike thanks to using low impedance and complementary conductor items. Afterwards these parts conduct and transfer the high lightning currents into the ground at the safest way. Such a coherent system enables the lightning strike to be arrested and transferred while providing maximum protection to the structure and human beings as well.
In a nutshell, there can be listed four types of lightning protection/prevention systems for protecting structures and human being against lightning:
1. Conventional Franklin rods,
2. Meshed method conductors,
3. Faraday cage method,
4. Early streamer emission type air terminals
1. Conventional Franklin Rods
First known lightning protection systems in modern means were originally invented by President Benjamin Franklin in 1753. This type of lightning protectors were made up of a typically 6 metres high tapered copper rod which covered the structure in order to be protected and this rods were connected to two seperate down conductors and two earthing system as well.
For the protection radius of such type of Lightning air protection rod was very strick up to 30 meters meter in radii means. It is obviously only can be used for protecting small structure areas or zones such as households, chimneys, water tanks, watch towers, air masts and gardens.
2. Meshed Method Conductors
Meshed method type lightning protection, originally oriented from the Faraday cage installations, merely consist of some meshed conductors which dominate covering the roofs and side walls of the structures whereas conventional lightning rods only spot some particular points with its rod system for protection.
In action, meshed air conductors are put around the edge and sides of the roof and on the very high points. Such a network of conductors are followed by an external perimeter down the to ground. The mesh size can be selected between 4 and 16 meters according to the types of protection required for the building.
Top parts of the down conductors are linked to the walls and size afterwards they are connected to the meshed parts of the roofs then finally to the bottom earthing systems for safe grounding of electricity.
3. Faraday Cage Method
Regarding this method mentioned structure to be protected by Faraday cage installation method firstly would be covered by linked conductors alike in meshed method technic. Thus, there can be found a continuous and constant linked-conductor way from the parts located in the top of the structure, including the grounding materials, to the earhing unit. This installed cage obtains many attractors (arresters) created by conductors completed by X-axis way connections then these are to be connected to a following grounding system. Every metal parts on the roof or the top area that are connected to the grounding whether it is on purpose or unintentionally, should be connected to the this conducting system. If the height values of the parts of the structure/building differ from each other significantly, the lowest attractor/conductor unit should be connected to down-conductors of the highest parts in addition with its own down-conductor pieces. It enables the system of lightning protection to attract and conduct the lightning strikes to the ground safely.
4. Early Streamer Emissions Type Air Terminals
The basic principle of an Early Streamer Emission (ESE) type lightning air terminal can be defined as to protect a particular area located in a specific radius value (typically 10 meters to 107 meter) by generating artificial ion waves thanks to its ion generation devices, to increase the possibility of attraction of the lightning strike through these high potential electricity atmosphere an earlier than other types of lightning protection systems. Early Streaming capacity of an standard ESE can be measured with it is DeltaT(ΔT) value. In NFC 17-102/2011 ESE Standard, projected DeltaT values of ESEs are stated from 10 to 60 microseconds. Lower and higher values cannot be assumed and evaluated as ESE in any means. For more information about ESE lightning protection logic please visit here.
ESEs perform their duties in a specific area determined by its DeltaT value, rather than protecting only one building or a structure. These types of lightning terminals can be assumed as more technological and modern types than conventional types. They can be tested manually or remotely thanks to their remote testing opportunities.
