Thwarting Mother Nature: many industries and Fortune 500 companies are embracing DAS to protect personnel, vital assets and processes
By Del Williams
August 6, 2002 — Across industries, the power of lightning strikes to injure personnel, destroy assets, and disrupt processes through fire, explosion, or electrical damage is clear.
“Lightning strikes cause more deaths, injuries, and damage than all other environmental elements combined, including hurricanes, tornadoes, and floods,” according to the US EPA Alert Lightning Hazard to Facilities Handling Flammable Substances, published in May 1997. “Lightning accounts for 61% of the accidents initiated by natural events,” confirms a 1995 Journal of Hazardous Materials report.
Even if the facility is not directly struck by lightning, secondary effects such as bound charge and electromagnetic pulses can fry sensitive circuitry in the vicinity. Failures may be catastrophic or a momentary or long-term lockup, requiring replacement, repair, reprogramming, or rebooting. For US corporations, preventing lightning strike damage would not only safeguard critical processes and save millions of dollars of equipment and facility damage each year, but also protect the health and productivity of personnel.
The Problem with Lightning Rod Concepts
The danger of a lightning strike is exacerbated by so-called “prevention” devices such as lightning rods and early streamer emitters, which are designed to collect and channel the force of a strike to ground. This 200-year old concept was never intended for protection of modern high-tech automated facilities, but rather barns and other wood structures of that era.
“The Franklin rod system is 200 years old and wasn’t built for today,” said Don Zipse, a seasoned electrical engineer specializing in electrical accidents, who was awarded the IEEE Standards Medallion for his work promoting electrical standards. “Its main drawback is that it actually attracts thousands of amps to flow next to your equipment. Do you really want lightning striking next to you unless you’re 100% sure you can control it?”
Doubts of Franklin rod and ESE effectiveness in high-risk field conditions were raised by the National Fire Protection Association (NFPA) Bryan Report, an independent evaluation panel on ESE lightning protection technology conducted by its Standards Council in September 1999. Among the conclusions reached: “Neither the ESE air terminals nor the conventional Franklin rod appear to be scientifically or technically sound when evaluated in field tests under natural lightning conditions.”
Given the random and destructive nature of lightning strikes, how can businesses protect their personnel, facilities, equipment, and processes – including those of a sensitive electronic nature such as data centers and control systems? The answer lies not in channeling lightning, but in preventing the charge from accumulating in the first place.
As a storm intensifies, charge separation continues within the cloud until the air between the cloud and earth can no longer act as an insulator and a strike occurs. The lightning strike “neutralizes” any charge difference between the cloud and ground, a process similar to shorting out the terminals of a battery. When structures sit between the earth and the clouds, they are likewise charged. Since they short out a portion of the separating air space, they can trigger a strike.
The lightning strike hazard for a given facility depends on a number of factors, including the facility’s location, size, and shape. The characteristics of a structure – its height, shape, size and orientation – influence the hazard. Taller structures tend to collect strikes from storm clouds in adjacent areas and trigger additional strikes as well. The larger the structure size, the greater the hazard of lightning exposure.
One technology, the Dissipation Array System (DAS), has proven to be the preventative solution for lightning protection ( topping 30,000 system years with 99.7% reliability, and cutting storm-induced voltages by up to 7,000% in protected zones, thus reducing lightning risk. DAS, a proprietary application of Charge Transfer Technology, originated as a lightning prevention system that the former chief engineer for NASA’s Apollo moon landing mission and space shuttle design team developed to protect high-risk mission facilities.
DAS is based on a natural phenomenon known to scientists for centuries as the “point discharge” principle, where a sharp point in a strong electrostatic field will leak off electrons by ionizing adjacent air molecules, providing the point’s potential is raised 10,000 volts above that of its surroundings. It employs the point discharge principle by providing thousands of points with specific point separation that simultaneously produce ions over a large area, thus preventing the formation of a streamer, the precursor of a lightning strike. DAS prevents strikes by continually lowering the voltage differential between the ground and the charged cloud to well below lightning potential, even in the midst of a worst-case storm.
“With a charge transfer system like DAS, you’re neutralizing the leader, so the earth charge doesn’t flow back to the cloud above,” says Zipse, who currently chairs the IEEE’s Project 1576, a workgroup dedicated to developing a standard for lightning protection systems at industrial and commercial installations. “That prevents lightning strikes and most of their secondary effects. DAS has improved on the naturally occurring charge transfer phenomenon, and engineered it to specific sites. The charge transfer system of preventing lightning strikes to protected areas is a valid concept and will replace the Franklin rod in many applications.”
Because it prevents rather than redirects lightning, DAS is possibly the best long-term solution to lightning strike problems. One company, Lightning Eliminators and Consultants, Inc. (LEC), based in Boulder, Colorado, has long been at the forefront of DAS development. In the three decades since LEC introduced DAS into the U.S. marketplace, it has been the only lightning protection system proven to prevent lightning strikes to any protected facility.
Corporate DAS success stories
Lee Ayers, System Engineer for the Mid-Carolina Electric Cooperative a distribution utility in Lexington, South Carolina turned to DAS after suffering severe lightning-related damage. “If a single substation was hit, we could lose as many as four to five thousand customers in the initial outage,” said Ayers, whose facility serves about 42,000 customers in the Columbia, SC area. “Total replacement costs for damaged equipment was over a million dollars during a five-year period…the transformers cost about a quarter million each. Our insurance carrier was constantly raising our rates and were pushing us to do something to cut their losses.”
The benefits of deploying LEC’s DAS equipment were significant, according to Ayers. “Over a comparable five-year period, our losses to collateral lightning damage on the protected facilities probably amount to no more than $50,000.” Mid-Carolina has since made DAS standard on all new installations, and Ayers has recommended the system to other utilities facing electrical storm damage.
Lightning Eliminators & Consultants, Inc. specializes in designing, manufacturing and installing integrated, engineered systems to prevent and eliminate all lightning related problems. For more information about LEC Inc. and the how the Dissipation Array System can protect a facility, contact the company at 6687 Arapahoe Road, Boulder, Colorado 80303; tel. 303.447.2828; FAX 303.447.8122; email: firstname.lastname@example.org or visit their website at www.lightningeliminators.com.
Author Del Williams is a technical writer based in Torrance, California.