Lightning
Protection
The goal of installing lightning protection on a building or facility
is to prevent physical damage to the structure. We often hear people say
that their facility was hit by lightning. If a building actually is directly
hit by lightning, there will be bricks, wood, concrete, glass, shingles
and other parts damaged or even missing. What we normally hear of are really
close proximity hits. The lightning strikes a tree, a utility pole, or
the earth and the energy from the lightning strike enters the facility
and causes damage.
However, lightning does strike buildings. Given that we can not prevent
lightning strikes, the best approach is to control of the strike energy
and not Mother Nature. There are several ways to control this. The most
common and least expensive way is to install lightning rods on the top
of the structure. This is commonly referred to as a Franklin system.
In a Franklin system, the lightning rods are placed around the perimeter
of the roof, in large open areas as on a flat roof, and on peaks according
to a prescribed procedure. These rods (air terminals) are connected by
heavy conducting cables and terminated in an earth grounding system. The
theory is to attract the lightning strike to the air terminals and lead
the energy into the ground where it can dissipate and not harm the physical
structure of the building.
There is another method of facility protection known as ionizing lightning
conductors. These devices mount on top of the facility and are designed
to reduce the the electric ion feld between the storm cloud and the facility.
By doing so, the probability of a lightning strike is reduced. If a lightning
strike hits the ionizing unit, it then acts as a lightning rod.
A well-designed ground system is key to any lightning protection system.
The energy introduced into the earth must have an efficient and effective
means of dissipation. The earth, itself, is a poor conductor. A well designed
grounding system can provide the attractive path and means to dissipate
the energy from the lightning strike.
For total facility protection, most all lightning protection systems
require the installation of transient voltage surge suppressors (TVSS)
on communication, data, signal, telephone,or other electrical or electronic
lines that enter or exit the facility. Large amounts of energy is being
introduced into the earth from the lightning strike. This energy must not
be allowed to erupt into the facility.
Since its inception in 1960, Harger has become a leader in the lightning
protection industry. Founded on the principles of honesty, integrity, and
technical expertise, Harger has been able to provide lightning protection
solutions for many satisfied customers.
