In the recent past, we have had to contend with tragic news about people being struck by lightning.

We might remember the case where at least 16 people were killed and dozens injured after lightning struck an SDA church in Rwanda on March 10, 2018.

Many other cases have been reported from western Kenya. Check end of post for the linked articles.

In most of these cases, the victims were actually already sheltering in a building when the lightning struck.

As engineers, we would ask, were these buildings protected from lightning?

If a certain area were prone to lightning, wouldn’t it be prudent to protect it from lightning? Even if it is basic one floor building?

I have worked on several projects that needed lightning protection and I can affirm that it is not an expensive scheme. Especially for churches and mosques, it is necessary that they have lightning protection.

Benjamin Franklin, who never finished formal basic education, was the inventor of a Lightning rod, one of the key components in a lightning protection scheme. Therefore, it is not a complex system.

However, Lightning protection is one of those engineering systems that remains a mystery to many, and often a cost-engineering target for those who do not understand the purpose of a lightning protection system. Many Architects, Quantity Surveyors and even some engineers will quickly target Lightning protection in any situation where there are budget constraints. It is the first service that is eliminated. But is it worth it? Is it not revealing that we are short-term minded professionals when we target such a key service? We reason that our work ends at design stage. A decade later, lightning strikes, leaves it victims, but no one bothers to query who the original designers of such structures were. This is another case of what happens when professionals do not have a skin in the game.

Like many other electrical engineering systems, lightning protection is not necessarily a “design preference,” .The need for a lightning protection system is determined by the national requirements and oftentimes the facility’s insurance carrier.

Merriam-Webster defines lightning as “the flashing of light produced by a discharge of atmospheric electricity; also: the discharge itself.” We know that lightning is a 30,000A to 100,000A example of this concept. Considering most residential circuits are 15A, the magnitude of one lightning strike is a significant amount of energy. A bolt of lightning generates 300kV

The primary reason for a lightning protection system is to route that electrical energy to a less destructive path to ground — instead of traveling through the building’s electrical wiring, water piping, structure, or low-voltage cabling paths where it could create significant chaos inside the building. A lightning protection system does not completely eliminate the damage that can be caused to a structure, but it can certainly decrease the damage by routing the energy directly to ground instead of giving it free reign of the building. Even with the air terminals and down leads, there is always a risk of side-flash, which is one of the primary reasons the NEC requires all low-voltage cabling to be located a minimum of 2 meters from lightning protection cables.

Not all areas of the country are as susceptible to lightning strikes, and not all structures require a lightning protection system. The location, height, and configuration of a structure play a big part in determining if a lightning protection system is necessary.

One final thing to be mindful of is if a lightning protection system is installed, it needs to be installed correctly to assure you are adding safety and protection to the building instead of additional risk. Remember, any gap in the system provides an area of vulnerability for the structure.

If you have a construction project, ensure you engage qualified professionals (electrical engineers) to design and supervise installation of lightning protections schemes in your building.

 


 

At least 16 killed as lightning strikes SDA church in Rwanda

Lightning kills three family members in Tharaka Nithi

Western Kenya preps for lightning strikes

Lightning Strike Injures 10 Kenyan Students

 

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