Controlling your risk by Bob Carruth

As Risk Control Manager for the NCACC, Bob Carruth manages the operation of the Risk Control Team for the Risk Management Pools. The team assists members with development of safety policies and programs and identification of liability exposures and controls. Carruth is a Certified Safety Professional and is certified as an Associate – Risk Management.  For archives of this column click here

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Sep 23

Lightning – Our Sneaky Menace

Posted on September 23, 2016 at 10:35 AM by Todd McGee

What do you think is the most common property-related claim for the Risk Management Pools? Although we tend to focus on the wind, rain, or fire damage claims that occur each year, none of these qualify (unless they occur as part of a named storm).
If you guessed lightning strikes, then give yourself a gold star. Since 2010, 172 lightning strikes have resulted in close to $1.5 million in property losses for the Risk Management Pools. This works out to more than $11,000 being paid out every time a claim occurs.  
It is easy to take a fatalistic view of lightning strikes, as it seems as though there is really nothing that can be done about them. In some ways, this is true, but preventative measures can be taken to reduce the effects of a strike, and ensure the county’s assets remain protected. 
First, let’s take a look at how lightning actually works. In a typical storm cloud, positive and negative ions separate from each other like a magnet. The negative ions gather near the bottom of the cloud, the positive ions near the top. At the same time, on the ground below, positive ions get drawn to the cloud above, concentrating in higher objects such as trees or towers. Since opposites attract, the positive and negative ions try to unite with each other. When this occurs, the positive ions surge upward through the established path and create the lightning bolt. This all occurs in less than one second. 
A lightning bolt carries between 2,000 – 50,000 amps of current (average residential amperage is 200). The lightning current can take many paths from the ground to the cloud, often traveling along multiple pathways, always looking for the path of least resistance. This not only includes electrical or communications lines, but also plumbing, building frames, and even human flesh. Anything in its path that is combustible will either be vaporized or ignited, as the temperature of a lightning bolt also exceeds 50,000 degrees, five times hotter than the sun. A bolt of lightning is one of the highest concentrations of energy found on earth, and some bolts have traveled as far as 40 miles!
Historically, lightning strikes have caused billions of dollars of damage to structures, primarily due to the risk of a fire from the heat generated. These were caused from direct strikes to these structures. In the last 20-30 years, however, lightning damage has increased, primarily due to the widespread power surge that can occur along electrical and communications lines, as well as the increased usage of sensitive electronic equipment. Many times, the first indication of a lightning strike is not the strike itself, but the malfunctioning of a motor or other piece of electronic equipment days or weeks after the strike actually occurs.
For North Carolina counties, lightning strikes most commonly affect communications equipment primarily related to the sheriff or emergency services. Another common area for lightning damage are water and wastewater facilities, mainly the motors and pumps. It becomes imperative, then, that measures are taken to protect and harden these types of equipment from damage. Although these have been found to be the most common, any other electronic equipment is subject to damage as well.
When looking at protection, it is easy to assume that the typical retail surge protector will suffice: after all, it is designed to trip in the event of a large surge of current. However, most of these devices are too slow to trigger in the event of a lightning strike, and the current and temperature generated would be the equivalent of shooting a mouse with a 12-gauge shotgun. When looking for surge protection, it is best to buy equipment that is designed and certified to provide lightning protection. In addition, energy providers such as Duke/Progress can advise and assist its customers with equipment that can be installed to arrest or dampen the current damaged by lightning and power surges.
The age-old remedy still works – the lightning rod. It is configured to provide that easy path to ground for the electrical current. One precaution, however, is that the system should be installed by a contractor licensed or well experienced in installing such systems.
Finally, lightning protection should always be considered when purchasing new electronic equipment or updating facilities. It is always much easier to design in the safety features than go back and try to retrofit. The few dollars extra spent on a project will prove to be worth it when the protection system kicks in and prevents a damaging electrical surge from a lightning strike. 
If you have any questions or would like additional assistance with reviewing your particular lightning protection, please contact your risk control specialist or our office at (919) 719-1150.