Considering Lightning Rod Protection? Talk to Us.
Since the dawn of civilization, lightning has inflicted a great deal of damage on the structures built by mankind. About 250 years ago, an effective method of protection became available when Benjamin Franklin invented the lightning rod. A great deal of the research done since then was regarding how to best utilize lightning rod protection to dissipate lightning at a reasonable cost.
A lightning protection system functions by
intercepting the direct lightning strike energy as it hits near a structure and
safely diverting it to the Earth. Lightning phenomena is roughly based on the
discharge of huge charge regions high in the atmosphere into the Earth. This
discharge initiates high overhead and starts a rapid descent “in the general
direction” of Earth with no real high resolution target. In other words, the
lightning does not have a real plan when it starts to fall, but only near the
end do the step leaders feel enough electric field influence to reach up and
connect. This all occurs in 10’s to 100’s of microseconds.
When you need a lightning rod protection,
there are many options available. Understanding how they work will help
determine what will meet your needs. And while none of them are wrong, some are
better suited for different applications.
The science of lightning rod protection was
born when Franklin
discovered that lightning was a form of electricity. The conventional
protection method consists of the following:
a) Deploying air terminals at suitable
points above the structure to act as sacrificial termination points for the
lightning strokes.
b) Dissipating the collected lightning
charges safely into the ground via ground rods that are connected to the air
terminals via down conductors.
c) Bonding the down conductors to any
nearby conducting objects in the building to prevent side flashes.
Dissipation
Array System
Charge dissipation, or charge transfer
technology uses point discharge to reduce static charge build-up. The purpose
is to prevent an electrical arc or current flow. Lightning
rods, with their single point, will reach a charge saturation level where
the point cannot disperse the charge faster than it is accumulated. These
points are where streamers form and attract downward leaders resulting in a
lightning strike. DAS terminals, on the other hand, are engineered with
thousands of points to maximize corona generation and ionize surrounding air
thus neutralizing accumulated charges. There’s not enough energy to initiate
the formation of an upward streamer, and the downward stepped leaders will look
for another target.
If you are considering lightning rod protection, your best bet is to talk to a lightning protection
specialist such as LEC as every site and budget will have different
considerations.
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