Thunderstorms occur virtually everywhere and that puts any building at risk. State-of-the-art certified lightning protection systems are a part of the electrical system design of thousands of commercial and public facilities worldwide and are designed to maximize protection of life and property.
Risk factors including your location, frequency of lightning and thunderstorms, soil composition and building occupancy determine the need for a lightning protection system.
Lightning Protection Systems
Lightning protection systems are designed to protect a structure and provide a specified path to harness and safely ground the super-charged current of the lightning bolt. The system neither attracts nor repels a strike, but receives the stroke and routes it harmlessly into the earth, thus discharging the dangerous electrical event.
Investment in a lightning protection system will protect your organization’s investment in its property and equipment.
If lightning protection systems are to be installed for the building(s) or structure(s), it should be designed and installed in accordance with:
- National Fire Protection Association (NFPA) 780, Standard for the Installation of Lightning Protection Systems
- Underwriters’ Laboratories, Inc. (UL) Standard 96A, Installation Requirements for Lightning Protection Systems
- Lightning Protection Institute (LPI) Standard 175, Standard of Practice for the Design – Installation – Inspection of Lightning Protection Systems
- All materials should comply in weight, size, and composition with the requirements of the UL 96 Materials Standards.
- All equipment should be UL listed and properly labeled.
- Equipment should be the manufacturer’s latest approved design of construction to suit the application where it is to be used in accordance with accepted industry standards and with NFPA, LPI and UL requirements.
Adequate Anchorage is Important
It is important to make sure the exposed elements of a lightning protection system are adequately anchored to the structure. In the aftermath of a high-wind event, it is not unusual to find that cables and components of lightning protection systems have broken loose from their anchorage points. The movement and impact of the lightning protection components, especially on membrane roofs, can lead to holes and cuts in the roof surface that lead to water intrusion.
While it is difficult to estimate the actual loads on the cables when they begin to move in strong winds, it is clear that installations with cables held in place with aluminum prongs on cleats are frequently inadequate in strong winds. Closed loop connectors are better suited for high-wind regions. For additional guidance for lighting protection system securement, refer to FEMA’s Rooftop Attachment of Lightning Protection Systems in High-Wind Regions, available at www.fema.gov.
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