For electrical engineers, contractors, installers, designers and other individuals whose jobs involve lightning protection systems and related equipment, understanding all the relevant standards can be a daunting task.
To learn and apply the intricate requirements outlined in a given code or standard, we recommend referring to the specific document first.
In this article, we will examine three of the most prominent U.S. lightning system design, installation and inspection documents. We answer the following questions to direct you to the right one:
- Why does each standard and organization exist?
- Where can I find the necessary information for a given situation?
- When is each applicable and how is it regulated?
UL (Underwriter Laboratories) and UL 96A
UL has been testing and certifying lightning protection equipment since 1908. They are the only U.S. Occupational Safety and Health Administration (OSHA) accredited and Nationally Recognized Testing Laboratory (NRTL) that offers Master Label® Certificate inspections for lightning protection systems.
What does UL do?
UL examines lightning protection system components and completed installations for compliance with UL’s internationally recognized standards for lightning protection systems and recognized national standards. Certificates are issued for structures that fully comply with the selected standard.
Which UL standard is relevant to lightning protection systems?
UL 96A, the Standard for Installation Requirements for Lightning Protection Systems, addresses the minimum requirements for installation of air terminals, cable conductors, fittings, connectors and fasteners used in quality lightning protection systems.
Because UL 96A instructs inspectors on what and how to review, the rules are intended to be very direct, with defined requirements and less room for user interpretations.
For the individual components referenced in UL 96A, those are evaluated to meet UL 96, the Product Standard for Lightning Protection Components.
What does UL 96A cover?
The installation requirements of UL 96A can apply to lightning protection systems on all types of structures. These requirements shall not apply to adjacent structures. An adjacent, or connected, structure should be considered a separate structure in need of its own UL 96A-compliant lightning protection system.
In addition to directing system designs, UL field inspections of completed lightning protection installations are done in accordance with UL 96A. Inspections by UL can result in a Master Label Certificate or a Letter of Findings. The difference between the two are based on the scope of the inspection. An inspection of an entire structure can result in a Master Label Certificate. Whereas, if the scope of the inspection is limited to anything less than the complete lightning protection system, it can be eligible for a Letter of Findings with specifically listed exceptions to the inspection.
Other standards are also covered under UL’s inspection program with additional scope and certificate requirements. More information can be found on UL’s website.
What does UL 96A not cover?
In terms of lightning protection system installations, these requirements should not be used for the production, handling or storage of ammunition, explosives, flammable liquids or gases and other explosive ingredients including dust.
It also does not cover lightning protection components, which are covered by the Standard for Lightning Protection Components, UL 96.
National Fire Protection Association (NFPA) and NFPA 780
According to the National Fire Protection Association (NFPA), the NFPA is a “global self-funded nonprofit organization, established in 1896, devoted to eliminating death, injury, property and economic loss due to fire, electrical and related hazards.”
What does the NFPA do?
To further than mission, the NFPA develops codes and standards that are revised and updated every three to five years. Each standard is developed through a structured process involving the public, NFPA Technical Committees, the Standards Council and other key parties.
Which NFPA standard is relevant to lightning protection systems?
NFPA 780, which was published in 1904 as the first document on lightning protection, is considered the national design guide for complete lightning protection systems in the U.S.
It provides lightning protection system installation requirements intended to safeguard people and property from fire risk and related hazards associated with lightning exposure. Every three years the standard is reviewed for updating.
What does NFPA 780 cover?
NFPA 780 covers traditional lightning protection system installation requirements for several structures, including:
- Ordinary structures
- Miscellaneous structures and special occupancies
- Heavy-duty stacks
- Structures containing flammable vapors, flammable gases or liquids that can give off flammable vapors
- Structures housing explosive materials
- Wind turbines
- Airfield lighting circuits
- Solar arrays
What does NFPA 780 not cover?
Excluded from this standard are facilities whose primary purpose is to generate electric power, including power generation, transmission and distribution. Most electrical utilities have separate standards covering their facility and equipment protection.
NFPA 780 also does not cover lightning protection system installation requirements for early streamer emission systems, but rather comprises traditional lightning interception systems.
UL can also inspect and certify installations according to NFPA 780.
Lightning Protection Institute (LPI) and LPI 175
The Lightning Protection Institute (LPI) is a “nationwide not-for-profit organization founded in 1955 to promote lightning protection education, awareness and safety.” Its members are manufacturers, contractors, scientists, architects, engineers and safety directors.
What does LPI do?
LPI designs and develops information resources on complete lightning protection systems for consumers and specifiers and sells educational materials to members in the construction industry. According to LPI, “the focus is to develop the total market for lightning protection” through:
- Promotion of National Standards with supporting loss data
- Experience from past design
- New information from research
In addition to LPI membership, the institute offers a Master Installer certification, Master Installer/Designer certification and Designer Inspector certification. To become certified, individuals must pass a series of written exams.
Which LPI standard is relevant to lightning protection systems?
LPI 175, the Standard of Practice for the Design, Installation and Inspection of Lightning Protection Systems, provides “nationally recognized methods for the proper design, installation and inspection of lightning protection systems and is used to study for LPI certification tests.”
What is the purpose of LPI 175?
LPI 175 is based on NFPA 780 and does not establish new requirements or precedents for lightning protection systems. Rather, what distinguishes LPI 175 from NFPA 780 and UL 96A is that it consists of a more concise list of checkpoints for LPI designers, installers and inspectors certified to easily reference while working on lightning protection systems.
LPI also publishes LPI 177 – 2017 Inspection Guide for Certified Systems. LPI describes this guide as:
“This 59 page pictorial booklet provides additional information for inspector professionals and serves as a companion document to the LPI 175 Standard of Practice for the Design – Installation – Inspection of Lightning Protection Systems.”
The LPI Inspection Program (LPI-IP)
The LPI also has an inspection program, LPI-IP, which can inspect and certify lightning protection installations to LPI 175, NFPA 780 and UL 96A, among others. As with UL, scope and limitation of the inspection can result in different certification levels (e.g. Master Installation Certification, Limited Scope Inspection, and more). More information on the LPI-IP can be found on the LPI-IP website.