~ National Lightning Safety Institute ~

Section 6.1

This paper was presented by Richard Kithil of NLSI at the International Lightning Detection Conference, in Tucson, Arizona, October 2002.

1. Overview

Since 1904 the National Fire Protection Association NFPA-780 Standard for the Installation of Lightning Protection Systems (NFPA-780) has been the de facto lightning protection document in the USA. While NFPA-780 has no authority or force of law, it describes minimum standards to residential, commercial and industrial facilities. It exempts itself from the electric utility industry and from explosives issues. NFPA-780 in the main describes how to install Franklin lightning rods. The purpose of this paper is to provide summaries of lesser-known, but more comprehensive, USA lightning protection documents. These publications may assist the specifying architect and engineer.

2. Alternatives

Ten alternative USA lightning protection documents are described in brief below:

2.1 American Petroleum Institute, API Recommended Practice 2003, Protection Against Ignitions Arising Out of Static, Lightning, and Stray Currents (1998). Chapter 5 discusses direct and indirect effects of lightning as well as protection of specific equipment. The introductory caveat is a useful reminder:

"The information in this section is based on the present state of the art against direct stroke lightning and indirect lightning currents. Perhaps the most significant property of lightning is its complexity. There is no such thing as a standard lightning stroke. Hence the behavior of lightning phenomena can best be described and analyzed in statistical terms. In general, the statistical distribution of lightning varies with terrain, altitude, latitude, and time of year. All these variations need to be considered in evaluating the risk posed by lightning and the design of any lightning protection system for a specific location. Even when all known precautions are employed, prevention or safe dissipation of direct stroke lightning can not be absolutely assured."

2.2 Department of Defense Grounding Bonding and Shielding for Electronic Equipments and Facilities, MIL-HDBK-419A (1987). MIL-419A emphasizes effective design, construction practices, test and acceptance procedures. Project engineers will find helpful data contained in the many drawings, charts, tables, figures and nomographs. Chapters include Earth Electrode Subsystems; Lightning Protection for Structures; Fault Protective Pubsystems; Signal Reference Subsystem for New Facilities; Grounding; Bonding; Shielding; Military Mobile Facilities; Fences; and, Inspection and Test Procedures. Upgrading existing facilities and equipment design criteria also are discussed in detail. MIL-419A contains considerable design detail, including useful illustrations.

2.3 Department of Energy bulletin DOE/EH-0530 (1996). This guideline document contains an events summary about some past DOE lightning losses. DOE has recorded 348 lightning losses to its facilities in the period 1990-2000. It presents a risk analysis protocol and contains recommendations for six key safety elements. Personnel safety tips also are described.

2.4 Federal Aviation Administration Standard FAA-STD-019c (1999), Lightning Protection, Grounding, Bonding and Shielding Requirements for Facilities (under revision). From the Foreword:

"This Standard contains 6 sections. Section 1 gives the scope and purpose of the standard. Section 2 lists reference documents. Section 3 gives the requirements for surge and transient protection, lightning protection, the earth electrode system, the electronic multi point ground system, the National Electrical Code (NEC) compliance, [and] bonding and shielding. Section 4 provides quality assurance requirements. Section 5 "Preparation for delivery" does not apply to this document. Section 6 contains notes and definitions." (Author’s Note: This excellent document is under revision, soon to come the STD-019d version.)

2.5 Institute of Electrical and Electronic Engineers, Recommended Practice for Grounding of Industrial and Commercial Power Systems, IEEE Std 142-1991. IEEE-142 contains useful information for the lightning protection engineer..."Lightning cannot be prevented; it can only be intercepted or diverted to a path that will, if well designed and constructed, not result in damage...The fundamental theory of lightning protection of structures is to provide means by which a discharge may enter and leave the earth without passing through paths of high resistance...It should be noted that the use of air terminals on a building or structure may increase the frequency of lightning strokes at that specific location. Although the building may be protected by a properly installed lightning protection system, the increased stroke frequency may have a detrimental effect on processes or operations within the building."

2.6 Institute of Electrical and Electronic Engineers, Recommended Practice for Powering and Grounding Electronic Equipment, IEEE Std 1100-1999. With a focus on power quality issues, including lightning, IEEE-1100 addresses "incompatibilities between power system characteristics and equipment tolerances." The good engineering practices described in IEEE-1100 encompass: site surveys and site power analysis; specification and selection of equipment and materials; recommended design and installation practices; a special focus on modern telecommunications and distributed computing problems; and, case histories to stimulate the creative thinking process so necessary to lightning mitigation problem-solving.

2.7 U.S. Air Force, Air Force Instruction 32-1065 (1998). 32-1065 is a civil engineering directive covering Grounding Systems in considerable detail. It assigns maintenance responsibilities and requirements for electrical grounding systems on Air Force installations, including equipment grounding, lightning protection, and static protection. Considerable design detail, not found elsewhere, is contained in 32-1065.

2.8 U.S. Navy, NAVSEA OP 5, Vol. I, Ammunition and Explosives Ashore: Safety Regulations for Handling, Storage, Production, Renovation and Shipping (2001). Chapter 5 of OP 5 describes Electrical Requirements including static electricity, resistance, ground loops, interconnection of conductive bodies, testing and electrical and visual inspections. Chapter 6, Lightning Protection, discusses lightning detection, warning and policy procedures. It also further defines Navy on-shore standards for air terminal application, grounding, bonding, shielding, surge protection and testing in various explosives environments.

2.9 NASA KSC-STD-E-0012E, Facility Grounding and Lightning Protection (2001).

0012E describes lightning protection measures for Kennedy Space Center and for Cape Canaveral Air Force Station. Information not usually found in many other codes includes: treatment of underground duct banks; considerable design detail of Overhead Ground/Grid Wire and Mast-type air terminals; performance specifications for Surge Protection Devices; earth grounding counterpoise design; instrumentation and electronic equipment grounding; and guard shacks safety.

2.10 US Army PAM 385-64 Ammunition and Explosives Safety Standards, Chapters 12 & 13 (1999). Detailed descriptions of alternative air terminal designs, bonding, shielding, grounding, surge protection, maintenance and testing will be found here. Lightning warning systems, conductor sizing, flashover issues, and earth resistivity testing also are discussed.

3.0 Summary

Not described in this Paper are other helpful sources in the international literature. Those persons seeking to build a comprehensive library of lightning protection standards should consider the following: British BS 6651 (1999) "Code of Practice for Protection of Structures against Lightning"; Australian AS 1768 (1991), "Lightning Protection"; Singapore CP33 (199X), "Code of Practice for Lightning Protection"; International Telecommunications Union ITU-T Chapters 9 & 10 "The Protection of Telecommunications Lines and Equipment Against Lightning Strikes (1995); South African SABS-03-1985 (1985), "The Protection of Structures Against Lightning"; the German Standard DIN 57185 "Lightning Protection System (trans. 1983); and the Polish Code PN-86 (1987) "Lightning Protection of Structures" among others.

The single most valuable document in this field is the International Electrotechnical Commission (IEC) International Standard IEC 61024 series "Protection of Structures Against Lightning." This European-wide, peer-reviewed, science-based document should be required reading for advocates of NFPA-780.

4.0 References

4.1 American Petroleum Institute, 1991: Protection Against Ignitions Arising out of Static, Lightning and Stray Currents, 1998 Edition, API 2003, Washington, DC.

4.2 Department of Air Force, Air Force Instruction 32-1065, Grounding Systems, Civil Engineering, 29 April 1994.

4.3 Department of Defense, Explosives Safety Board, DDESB 6055.9 Chapter 7 Lightning Protection, August 1997. (See: http://www.hqda.army.mil/ddesb/esb.html)

4.4 Department of Navy, 2001: Ammunition and Explosives Ashore: Safety Regulations for Handling, Storage, Production, Renovation and Shipping - NAVSEA OP 5, Vol. 1, Seventh Edition.

4.5 Department of Navy, 1997: Electrical Storm Warning Procedure for NUWC, Keyport, SOP No. 04-0006-95.A.

4.6 Department of Transportation, Federal Aviation Administration, 1999: Standard, Lightning Protection, Grounding, Bonding and Shielding Requirements for Facilities, FAA-STD-019c, Washington DC.

4.7 Hasbrouck, R.T. and Majumdar, K.C., 1995: Development of a Guidance Document for Lightning Protection of DOE Facilities, Proc., 2nd International Symposium on Electromagnetic Compatibility and Electromagnetic Ecology, June 26-30, 1995, St. Petersburg, Russia.

4.8 IEEE Emerald Book; IEEE STANDARD 1100-1999, Recommended Practice for Powering and Grounding for Sensitive Electronic Equipment, IEEE Standards Department, Piscataway, NY.

4.9 IEEE Green Book; IEEE STANDARD 142-1982; Recommended Practice for Grounding of Industrial and Commercial Power Systems, IEEE Standards Department, Piscataway, NY.

4.10 IEEE Std 1243 December, 1997: IEEE Guide for Improving the Lightning Performance of Transmission Lines, IEEE Standards Department, Piscataway, NY.

4.11 MIL-HDBK-419A: Grounding, Bonding and Shielding for Electronic Equipments and Facilities, 29 Dec 1987.

4.12 MIL-STD-188-124B: Grounding Bonding and Shielding for Common Long Haul Tactical Communications Systems, including Ground Based Communications - Electrical Facilities and Equipments, 1 Feb 1992.

4.13 National Fire Protection Association: Standard for Installation of Lightning Protection Systems, 2000 Edition, ANSI/NFPA 780, National Fire Protection Association, Quincy, MA.

4.14 Mousa, AM and Srivastava KD, 1998: Shielding Tall Structures Against Direct Lightning Strokes, Proc. Canadian Conf. On Electrical and Computer Engineering, Vancouver BC.