How Does a Lightning Protection System Work?
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Modern lightning protection systems have come a long way from when they were first built in the early 1900s. These systems are put in place to lower the risk of damage that lightning can present when it strikes a building or structure. Lightning protection systems, although diversified in brand, basically utilize the same types of parts in order to work. Air terminals are located externally on a high point of a structure's surface and are meant to take lightning strikes. These are better known as lightning rods or strike termination devices that can be visibly seen on rooftops. Other typical parts of a lightning protection system include supports, grounding terminals, bonding conductors and connectors, all of which are used to help lower the risk of damage to a structure from lightning.
Accepting and Neutralizing Current
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Lightning occurs when a negatively charged cloud passes over positively charged Earth. If the air between the cloud and the ground is dry, then lightning has no conductive path to follow. Rainstorms provide a perfect conduction outlet between the oppositely charged cloud and Earth, as humidity or rain allows a conductive path for lighting to travel down toward the Earth. When a lightning protection system is installed on a structure, the likelihood of lightning striking the conductive rod on the roof of a building instead of the building itself is increased. After the lightning strikes the rod or strike termination device, the current of electricity flows through the predetermined conductive path of the system's terminals. As current flows through the lightning protection system, it takes the easiest path of conductivity and dissipation to the ground. The system helps to neutralize some of the negative charge through emitting a positive charge and accepting the negative overflow of electrical current into the system.
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Grounding the Current
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Electrical current that is accepted by the system flows toward the ground where it dissipates safely. The current follows through separate conductive cables that are in place from the system to a grounding rod or wire mesh that is buried deep underground. This grounding material is usually buried close to a building and allows electrical current to escape and discharge into the ground. Although lightning protection systems can greatly reduce the risk of damage to a structure as a result of lightning, they cannot provide complete protection or a guarantee. Nature, as we all know, has a mind of its own and cannot always be predictable. Without lightning protection systems, solid material, such as wood or brick, that is not conductive is more susceptible to fire damage or even explosion. Explosion or fire can happen in solid materials when moisture inside them is suddenly heated to its steaming point, which can manifest in less than 0.005 of a second with a lightning strike.
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