November 24, 2015
By Kim Loehr
Lightning packs a powerful punch. A single bolt carries up to 100 million volts of electricity and has the power to rip through roofs, explode walls of brick and concrete, wreak havoc with circuitry and ignite deadly fires. It is no wonder experts with the U.S. National Weather Service have dubbed lightning as “the most dangerous and frequently encountered weather hazard experienced by most people each year.”
While lightning poses significant safety and economic concerns, there is good news for design/construction professionals and property owners. Unlike threats posed by tornadoes, hurricanes, or floods, lightning is a force of nature for which affordable and reliable protection is available. A lightning protection system that meets all applicable safety standards from the onset will ensure system reliability for the future.
As long as lightning’s electricity is confined to a conductive path (i.e. the quickest route to the ground), it will not cause damage, explains Bud VanSickle, executive director for the Lightning Protection Institute (LPI). “Only when electricity encounters resistance does it cause destruction,” he says. (LPI is a leading resource for lightning protection and lightning safety information. Visit www.lightning.org for a list of certified contractors in Canada and the United States Information about follow-up, third-party inspection services is available at www.lpi-ip.com.)
Resistance is the concept behind arc-welding. When electrical current runs through an arc-welder, the resistance it encounters while arcing through air generates the heat necessary to melt steel. Unlike the arc welder, the highly conductive copper and aluminum materials used in a lightning protection system provide a low resistance path to safely ground lightning’s dangerous electricity without allowing it to ‘jump’ or ‘sideflash.’ When the lightning protection network is in place, the lightning strike is intercepted and directed to ground without impact to the structure, occupants, or contents.
Lightning protection standards
Lightning systems must include the following elements:
Failure to make proper provisions for special grounding techniques of these five elements can result in inadequate levels of protection.
Construction managers, engineers, and affected consumers should familiarize themselves with the fundamentals of lightning protection specification, installation, and inspection. While reference to the safety standards is crucial for proper installation and application, recent changes in Canadian regulation regarding inspections for lightning protection may be a source of confusion and misinformation about the trade and industry best practices.
In January 2011, the Government of Ontario repealed its Regulation 712, also known as the Lightning Rods Act. The repeal ceased the administration of lightning rod inspections by the Office of the Fire Marshal (OFM). The act was first introduced in 1922 to address concerns about inadequate lightning protection system installations in Ontario. While the regulation did not require system installations, it provided a licensing system for distributors and installers and authorized the OFM to inspect systems.
Although the inspections will no longer be provided by the fire marshal, OFM continues to offer guidance for lightning protection system installations and is still recommending compliance with established safety standards—the Canadian Standards Association (CSA), National Fire Protection Association (NFPA) and Underwriters Laboratory (UL).
“There is nothing currently in the building code about lightning protection installation or inspections for structures in Alberta,” said Carol Henke, public information officer at the Calgary Fire Department.
Henke explained different provinces in Canada have different codes that can be augmented with bylaws to respond to the needs of a particular region. She said fire safety officials support lightning protection efforts in Canada regardless of building code requirements or omissions.
“Our department is committed to serving the community through excellence in prevention, education, and protection and by delivering fire safety outreach to Calgarians,” said Henke. “Naturally, we are very supportive of safety measures that go above and beyond to protect citizens.”
Underwriters Laboratories has recently received accreditation by the Standards Council of Canada (SCC) to develop lightning protection standards for the region. In an effort to develop cohesive lightning protection standards for Canada, UL has proposed UL 96, Standard for Safety of Lightning Protection Components become harmonized for use to align with U.S. practices. To facilitate this process, UL has expanded the existing membership of its Standards Technical Panel (STP) 96 (on lightning protection components) to include applicable Canadian stakeholders. In a recent bulletin, addressed to members of the Standards Technical Panel, UL summarized efforts for UL 96 to be issued as a National Standard of Canada, stating:
STP 96 Members will be responsible for reviewing the standard, commenting and balloting efforts.
According to the bulletin, UL plans to hold a STP 96 meeting this summer in Toronto to discuss standard-related topics for lightning protection. (This writer’s repeated attempts to receive comment from UL for this article were unsuccessful. Loehr did speak with Maria Iafano, director, UL Standards of Canada. While Iafano was unable to provide a statement or confirm details regarding the Toronto meeting, she did offer that UL encourages participation from interested stakeholders across Canada. Those wishing to become involved and stay informed about the development of UL standards for Canada, may contact UL’s Maria Iafano, director, UL Standards of Canada at email@example.com.)
The Lightning Protection Institute (LPI) is also increasing efforts to improve the best practices for lightning protection in Canada.
“LPI membership includes installation companies in Canada committed to bringing this high level of service to their markets, along with U.S. member contractors who work in the provinces,” said VanSickle. “We believe the market for lightning protection is going through a transitional period and LPI plans to be an active partner in developing professional quality solutions that eliminate concerns for all users of lightning protection.”
While NFPA, UL, and LPI all publish safety information and installation standards for lightning protection, LPI is the only organization of the three founded specifically to study lightning protection. The organization provides a certification and testing program to qualify competence in lightning protection installation, design and inspection. LPI-certified lightning protection specialists, known as ‘Master Installers’ or ‘Master Installer/Designers’ lead the industry in experience and education and know how to interpret the safety standards. They also provide the proper third-party inspection requirements for quality assurance closeout.
In accordance with its stated mission to provide quality in lightning protection for the safety of people and property, LPI relies on two major programs to ensure systems meet the expectations of the public.
LPI qualifies installation companies through its certification testing program, including a series of exams to assure contractors are qualified to the current requirements of the standards. The LPI-IP field inspection program provides independent third-party inspectors who can ensure system compliance in accordance with specified safety standards, explained VanSickle.
“While Canadian Standards Association (CSA) B72 M87, Installation Code for Lightning Protection, is the national standard for Canada, NFPA 780, Standard for the Installation of Lightning, and UL 96A, Standard for Installation Requirements for Lightning Protection Systems, are also commonly specified for our system installations,” said Murray Van Norman of Western Lightning Protection in Winnipeg, an LPI Master Installer member company. “Since the CSA doesn’t have a certification process, we often use LPI to certify our systems. We believe certification and inspection are important to ensure code-compliant lightning protection systems are installed,” added Van Norman.
Western Lightning Protection recently completed a standard-compliant lightning protection system for the Canadian Museum for Human Rights in Winnipeg. (For more information on the Canadian Museum of Human Rights, see the May 2014 article in Construction Canada by Neb Erakovic, M.A.Sc., P.Eng., Crispin Howes, P.Eng., and Terry Dawson, M.Eng., P.Eng.)
The 23-storey structure composed of glass, steel, and stone is the first national museum to be located outside of Ottawa. According to Van Norman, a 5000-m (16,404-ft) glass cloud characterizes the museum’s unique architecture.
The CAN/CSA B72 M87 Code references lightning protection guidelines for residences, places of public assembly, and industrial buildings, including structures with explosive or flammable contents. However, it neither covers protection of electrical transmission, distribution, and communication systems, nor provides specific guidelines for quality control and third-party inspection.
Quality control for lightning protection has always been a priority for the industry and new concerns are on the rise due to a trend developing with outside trades like electrical and roofing contractors attempting to grow their business by dabbling in lightning protection installation. This can be a problem, as lightning protection specifications call for installation in accordance with safety standards, use of UL-listed materials and work performed by LPI-certified lightning protection specialists and/or UL-listed installers.
The International Association of Electrical Inspectors (IAEI) reiterates the importance of LPI-certified and UL-listed installers for lightning protection applications. In 2011, IAEI devoted a new chapter to its 10th edition of the Soares Book on Grounding and Bonding— “The Fundamentals of Lightning Protection.” The handbook now includes a reminder to electrical contractors that, “installation of a lightning protection system is much different from the installation of electrical service wiring.”
According to Soares Handbook, “specialized material and installation methods such as those specified in NFPA 780 and UL 96 are required and the system should only be installed by qualified personnel trained and certified in the installation of lightning protection systems.”
LPI Inspection Program (LPI-IP) is a program that facilitates onsite inspection services, follow-up inspection reports, and the issuance of certification for lightning protection systems that comply with LPI, NFPA, and UL standards. LPI-IP plans to expand its third-party inspection services with Intertek throughout Canada, especially since the program’s inspections are now accepted in MasterSpec as a quality control inspection option for lightning protection. The LPI-IP Inspection Program provides system certifications with a three-year expiration date to complement the NFPA three-year code review process and keep pace with new technology.
“Lightning can generate up to 200 kA of electric energy, so quality control for systems is crucial,” said VanSickle. “Independent review provides the purest evidence that the installing contractor has met all industry guidelines and complied with recommended practices and safety standards.”
Guidelines to understanding the inspection process
Since lightning protection is a specialized industry, it can be difficult for those not familiar with these systems to know what to expect when it comes to third-party inspection.
If possible, it is always a good idea for the installing contractor or project manager (PM) to be onsite during a lightning protection inspection. This gives the owner or PM an opportunity to observe the inspector and understand more about the system and its components. It is likely the lightning protection contractor will want to be present, as well, in the event that minor repairs or upgrades to the system are needed.
Depending on the project, the inspector will issue a certification or report several days/weeks after the inspection. Most lightning protection contractors address installation repairs or issues during the inspection, but if this is unfeasible, the inspector forwards a variance or noncompliance letter to the contractor. This report summarizes issues and corrective measures needed for system compliance. A follow-up inspection or appropriate documentation of corrective measures is typically required to verify compliance so inspection certification can be issued.
Most reputable contractors will provide warranty information and industry recommendations for periodic inspections and follow-up services. Timetables and arrangements for third-party inspections are typically controlled by the inspection entity (LPI-IP or UL) and not mandated by the lightning protection installer, so customers should be wary of contractors who make promises or guarantees that sound too good to be true.
Lightning protection inspection services typically base their costs on the perimeter size of the structure. Geographic factors may need to be considered and minimal fees for additional services such as ground tests or follow-up reports may also apply. It is always a good idea to ask about inspection costs up-front. While a third-party inspection may add an additional cost to the contract, it should not be a deciding factor with the owner/customer.
|LIGHTNING PROTECTION GLOSSARY OF TERMS|
|The following terms are defined by the Lightning Protection Institute (LPI) 175, Standard of Practice for Design, Installation, and Inspection:
Authority having jurisdiction (AHJ): The organization, office, or individual responsible for approving equipment, materials, an installation, or procedure.
Bonding: An electrical connection between an electrically conductive object and a component of a lightning protection system intended to significantly reduce potential differences created by lightning currents.
Bonding conductor: A conductor used for potential equalization between grounded metal bodies or electrically conductive objects and a lightning protection system.
Cable: A factory assembly combining multiple wire strands together to form a single conductor.
Catenary lightning protection system: A lightning protection system consisting of one or more overhead ground wires (also known as ‘overhead shielding’).
Conductors: Devices defined by LPI 175 as suitable to carry lightning current or make bonding interconnections.
Fastener: A component (or set) used to securely attach materials to the structure.
Ground electrode: The portion of a lightning protection system, such as a ground rod, ground plate, or ground conductor installed for the purpose of providing electrical contact with the earth.
Labelled: Equipment or materials to which has been attached a label, symbol, or other identifying mark of an organization that is acceptable to the AHJ and concerned with product evaluation, that maintains periodic inspection of production of labelled equipment or materials, and by whose labeling the manufacturer indicates compliance with appropriate standards or performance in a specified manner.
Lightning protection system: A complete system of strike termination devices, main conductors (including conductive structural members), grounding electrodes, bonding or interconnecting conductors, surge suppression devices, and other connectors or fittings required to complete the system.
Listed: Equipment, materials, or services included in a list published by an organization that is acceptable to the AHJ and concerned with evaluation of products or services, that maintains periodic inspection of production of listed equipment or materials, or service meets appropriate designated standards or has been tested and found suitable for a specified purpose.
Strike termination device (air terminal/rod): Component of a lightning protection system that intercepts lightning flashes and connects them to a path to ground. Strike termination devices include air terminals, metal masts, qualified permanent metal parts of structures as described in LPI 175, and overhead ground wires installed in catenary lightning protection systems.
Surge protective device (SPD): A device intended for limiting surge voltages on equipment by diverting or limiting surge current that comprises at least one nonlinear component.
Transient voltage surge suppressor (TVSS): A subcycle disturbance in the ac waveform that is evidenced by a sharp, brief discontinuity of the waveform— it may be of either polarity and may be additive to, or subtractive from the nominal waveform.
Voltage protection rating (VPR): A rating (or ratings) selected by the manufacturer based on the measured limiting voltage determined when the SPD is subjected to a combination waveform with an open circuit voltage of 6 kV and a short-circuit current of 3 kA. The value is rounded up to the next highest l00 V level.
Zone of protection: The space adjacent to a lightning protection system that is substantially immune to direct lightning flashes.
Kim Loehr is communications director for the Lightning Protection Institute (LPI) and a partner member of the National Oceanic and Atmospheric Administration/National Weather Service (NOAA/NWS) Lightning Safety Awareness Team. She is also a member of the (NFPA’s) Building Fire Safety Systems section. Loehr can be reached via e-mail at firstname.lastname@example.org.
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