It's the complete system to protect a structure against the effects of lightning. The first Stop Rays have knowledge was developed in 1752 by Benjamin Franklin who also discovered that lightning was a physical / electrical phenomenon.
The Protection Systems Lightning (Stop rays) are made up of Franklin captors type or air captors mesh captor (Faraday cage) and are installed according to the NBR-5419/01 ABNT (Brazilian Technical Standards Association) .
The Rays can cause:
Contrary to what many think, the Stop Rays do not attract lightning on a stormy day. Its purpose is to convey to the highest points of the buildings, the same ionic potential we find in the earth, causing the ray search for the captors to discharge instead of the structures around the captors or the soil itself lying at lower levels in relation to the sensors.
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PROTECTION METHODS:
There are some ways to prepare adequate lightning protection. Among the most common found:
1) METHOD FRANKLIN - protection theory consists in the rotation of the tangent of a triangle around an axis (generatrix), whose opening angle is determined by a specific table, varying depending on the level of protection of the building and the building height.
1 - Captor type Franklin |
2 - galvanized mast |
3 - Supports insulators for masts |
4 - Mounting base and contraventagem |
5 - descent conductor (bare copper wire) |
6 - Supports insulators for lowering driver |
7 - Protection tube |
8 - Ground Loop |
2) METHOD OF FARADAY CAGE - is to launch horizontal cables on the roof of the building, modulated according to the level of protection. This system acts as an electrostatic shield, trying to keep the radius can pierce the armor and hit the building and also reducing the electric fields within it.
1 - Captor type finish air |
2 - Cable bare copper> |
3 - insulators Supports |
4 - Protection tube |
5 - Ground loop |
6 - Measuring Connector |
NOTE:. Other metal structures of the building to be protected against lightning can be used as natural captors or descent conductors such as: roofs, pillars, trusses, gutters, pipes, etc.
IMPORTANT: Stops Rays systems should not run (installed) without the prior achievement of specific project by engineer authorized by the competent body
The manufacture and marketing of radioactive captors is prohibited since 1989 by Resolution 04/89 of the CNEN (National Nuclear Energy Commission) published on 09/05/1989, because manufacturers have failed to prove its efficiency with the use of radioactive material. This type of sensor must be replaced, and after that the installation must be adapted to the ABNT 5419/93 leave that offers a minimum of security in order to minimize exposure to risks arising from a lightning strike.
RAY | one of the impulses of a lightning strike to the earth. Captor -. Of the outer SPDA designed to intercept lightning | |
CAPTOR | part of the external LPS intended to intercept lightning. | |
DOWN DRIVER | part of the SPDA designed to lead the lightning current from the sensor to the grounding system. | |
GROUND SYSTEM | part of the external LPS intended to conduct and disperse the lightning current in the ground. |
TYPE OF CONSTRUCTION
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PROTECTION LEVEL
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Building of explosives, flammable, industrial, chemical, nuclear, biochemical laboratories, factories of ammunition and fireworks, telecommunications stations, power plants, industrial heat with risk of fire, refineries, etc.
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I
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Residential buildings, industries, residential houses, agricultural establishments and farms with wooden structure.
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II
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Residential buildings, industries, residential houses, agricultural establishments and farms with wooden structure.
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III
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junk sheds or negligible content farms and agricultural establishments wooden structure;
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“If I made valuable discoveries, but was to have patience than any other talent.” - Isaac Newton