Report of Committee on Lightning Protection

Donald B. Davidson Jr., Chairman Los Alamos Natl Lab

Norman H. Davis I I I , Secretary Underwriters Laboratories Inc.

James H Baker, Lightning Safety Systems Winfred C. Barnett, Fred S. James & Co. of Georgia Rodney B. Bent, Atlantic Scientific Corp. Theodore Bernstein, Elecl. & Computer Engr. Dept. Ignacio T. Cruz, Dept. of Defense (DOD) Thomas P. Dowling, Institute of Makers of Explosives Henry K. E l l io t t , Industrial Risk Insurers Douglas J. Franklin, Thompson Lightning Protection Inc. Marvin M. Frydenlund, Lightning Protection Inst. Mitchell A. Guthrie, Naval Surface Weapons Ctr.

Rep. US Navy Paul S. Hamer, Chevron Corp.

Rep. API R. D. Harger, Harger Lightning Protection Inc. William E. Heary, Heary Bros. Lightning Prot. Co. Inc. Richard W. Kragh, Kragh Engineering Inc. Andrew a. O'Connor, M&M Protection Consultants William Reardon, Factory Mutual Research R. E. Schuchardt, The Carl Bajohr Co. Inc. L. H. Sessler, Bell Communications Research Inc.

Rep. ECSA Harold G. VanSickle, A-C Lightning Security Inc.

Alternates

James H. Bluhm, Texaco Inc. Alternate to P. S. Hamer)

Robert E. Cripe, Independent Protection Co. Inc. Alternate to M. M. Frydenlund)

Thomas R. Harger, Harger Lightning Protection Inc. Alternate to R. D. Harger)

Kenneth P. Heary, Heary Bros. Lightning Prot. Co. Inc. Alternate to W. E. Heary)

John aaresk9, Industrial Risk Insurers Alternate to H. K. E l l io t t )

Timothy E. Russell, Underwriters Laboratories Inc. Alternate to N. H. Davis)

Allan P. Steffes, Thompson Lightning Prot. Inc. Alternate to D. J. Franklin)

Staff Liaison: Richard P. Bielen

This l i s t represents the membership at the time the Committee was balloted on the text of this edition. Since that time, changes in the membership may have occurred.

The Report of the Committee on Lightning Protection is presented for adoption.

This Report was prepared by the Technical Committee on Lightning Protection and proposes for adoption amendments to NFPA 78-1986, Lightning Protection Code. NFPA 78-1986 is published in Volume 3 of the 1988 National Fire Codes and in separate pamphlet form.

This Report has been submitted to let ter ballot of the Technical Committee on Lightning Protection which consists of 21 voting members; of whom 13 voted affirmatively, 2 negatively (Messrs. Dowling and Hamer), and G ballots were not returned (Messrs. Bent, Franklin, Frydenlund, Heary. O'Connor and Schuchardt).

Mr. Dowling voted negatively for the following reasons:

The Institute of Makers of Explosives (IME) is the safety association of the commercial explosives industry in the United States and Canada. Founded in 1913, IME is primarily concerned with safety in the manufacture, transportation, storage, handling and use of commerciald explosives. Member companies and their manufacturing subsidiaries produce about eighty percent of the four (4)

b i l l ion pounds of commercial explosive materials consumed annually in this country involving mining operations, quarrying, construction, demolition, earth moving and mineral exploration.

IME works closely with many government agencies - Bureau of Alcohol, Tobacco and Firearms (BATF), Department of Transportation (DOT), Mine Safety and Health Administration (MSHA), Office of Safety and Health Administration (OSHA) - developing standards designed to protect employees, users and the public at large. BATF and MSHA have promulgated regulations for safe storage of explosives. Heretofore, IME has always cooperated with NFPA on matters involving commercial explosives so as to enhance the common safety mission of both organizations.

The current NFPA Lightning Protection Code (NFPA 78) provides:

" I - I .2" This code does not cover lightning protection requirements for explosive manufacturing buildings and magazines . . .

*A-l-1.2 Lightning protecton systems for structures used for protection or storage of explosive materials require special consideration because of the sensit ivity to arc or spark ignition of the structure's contents . . ."

Mr. Dowling and the IME support the above exclusion.

The Lightning Protection Committee at i ts meeting in Las Vegas, Nevada, on March 10, 1988, recommended changing the scope of the existing Lightning Protection Code so as to include in i ts requirements the manufacture and storage of commercial explosives. This action was taken over the objection of Mr. Dowling who was the only representative of the commercial explosive industry present. I assure you that such action which wil l impact thousands of manufacturers, distributors and users of commercial explosives wi l l create a far greater reaction than lightning has inf l icted upon explosives over the last century.

Commercial explosive materials are stored in tens of thousands of approved and licensed magazines throughout the country. These fac i l i t ies are low profi le, judiciously located and adhere to sensible lightning protection strategies. The regulations of BATF, 27 C.F.R. Part 55, do not require lightning protection. Our industry, which has centuries of experience in the safe storage of explosives, now follows safety practices which have served its employees, customers and the public well without the use of lightning protection devices. I f there was a proven need, industry would actively support the proposed changes.

The commercial explosive industry is certainly not aware of problems associated with lightning and i ts storage act iv i t ies. Mr. Dowling and the IME do not believe a safety issue exists and are of the firm conviction that new hazards are created by the proposed changes. I f the mil i tary desires a change in lightning operations, we have no objection. There are, however, vast differences between commercial and mil i tary explosives and the manufacturing, transporting, hauling and storing of each varies greatly. They should not be treated alike.

Recommendations of NFPA and IME are frequently adopted by regulating agencies by reference. Accordingly, we are both faced with a heavy responsibility to insure that al l positions are just i f ied, impartial and divorced from product promotion.

Mr. Hamer voted negatively for the following r easons :

On Proposal 78-I (1-I.1) An important class of materials, flammable liquids, was le f t out of the scope when proposals were made for Chapter 6. This shortcoming wil l also be addressed for later proposals. The paragraph is also awkward as proposed.

Proposed Rewordinq: I-1.I This Code covers lightning protection

requirements for ordinary structures; miscellaneous structures and special occupancies; heavy-duty

352

stacks; structures containing flammable vapors, flammable gases, or l iquids which can give o f f flammable vapors; and structures housing explosives and energetic materials.

On Proposal 78-52 (4-6) The version l isted under "Committee Action" is a b i t confusing as to what comprises the lightning protection system. Liquids which can give o f f flammable vapors should also he included.

Proposed Rewording: 4-6 Concrete Tanks and Silos. Lightning

protection systems for concrete (including prestressed concrete) tanks containing flammable vapors, flammable gases, l iquids which can produce flammable vapors, and concrete silos containing materials susceptible to dust explosions, shall be provided with either external conductors or by conductors embedded in the concrete in accordance with Chapter 3 or 6.

Proposals 78-53 (Chapter 6 T i t le ) , 78-54 (6-I .1), 78-58 (6-4.1), and 78-61 (6-4.2) The proposals, as written, omit l iquids which can give o f f flammable vapors from their scope. This class of material should be added to remove ambiguity.

PropQsed Rewordinq: 78-53 Chapter 6 Protection for Structures

Containing Flammable Vapors, Flammable Gases, or Liquids Which Can Give Off Flammable Vapors.

78-54 6-1.1 This chapter applies to the protection of structures containing flammable vapors, flammable gases, or liquids which can give o f f flammable vapors. For the purpose of this chapter, the term structure shall apply to the vessel, tank, or other container in which this material is contained.

78-58 6-4.1 Aboveground Tanks at Atmosphere Pressure Containing Flammable Vapors or Liquids Which Can Give Off Flammable Vapors.

Start paragraph 6-4.2 as follows: "Earthen containers enclosing flammable vapors

or liquids which can give o f f flammable vapors, lined or unlined . . ."

On Proposal 78-67 (A-6- l . l ) The last sentence of the f i r s t paragraph "Flammable gases can also eminate from these l iquids when stored at atmospheric pressure" is incorrect. "Vapors" are a mixture, but "gases" are pure. Where flammable vapors are present, there wi l l always be a mixture and no pure gas. Delete this last sentence to remove ambiguity.

The second sentence should be modified to include ambient temperature as a normal condition.

The ambient temperature under which combustible liquids are normally sto~ed also precludes the release of flammable vapors.

Proposed Rewordino ( for the f i r s t paraqrBphJ: "Flammable vapors can emanate from a flammable

l iquid (flash point below lO0°F (37.8°C) when the temperature of the l iquid is at or above i ts flash point. This chapter applies to these liquids when stored at atmospheric pressure and ambient temperature. Combustible liquids stored under these conditions wi l l not release signif icant vapors since their flash point is defined to be at or above IOOOF (37.8°C). ''

353

78- I - ( I - I ) : Accept SUBMITTER: Technical Committee on Lightning Protection RECOMMENDATION: Modify I-1.1 as follows:

I-I.1 This Code covers lightning protection requirements for ordinary buildings, miscellaneous structures and special occupancies, heavy duty stacks, structures containing flammable vapors and flammable gases, and explosives manufacturing, and storage structures. SUBSTANTIATION: To reflect that Chapter 6 covers the protection of structures containing flammable vapors and flammable gases and that Chapter 7 now covers the protection of structures housing explosives. COMMITTEE ACTION: Accept.

78- 2 - (I-1.2): Accept SUBMITTER: Technical Committee on Lightning Protection RECOMMENDATIQN: Modify I-1.27 as follows:

I-1.2" This Code does not cover lightning protection requirements for electric generating, transmission, and distribution systems. SUBSTANTIATION: To allow for change in scope of NFPA 78 to include the addition of explosives manufacturing, operating, and storage structures. COMMITTEE ACTION: Accept.

(Log # 10) 78- 3 - (2-I): Reject S_UBMITTER: Roy B. Carpenter, Jr., Lightning Eliminators & Consultants, Inc. RECOMMENDATIO_N: Add as a new paragraph:

NFPA Standard Changes Required. Chapter 2 Terms 2-I General Terminology Lightning Protection System

(add) "Charge Dissipation System This term refers to systems as described and detailed

within Chapter 6 of this code. A charge Dissipation System is a complete system composed of an Ionizer (or Dissipator), conductors, and a Ground Current Collector; with al l the necessary connectors, f i t t ings required to complete the system." SUBSTANTIATION: The referenced NFPA Code makes no mention of the lightning protection system known as: "The Dissipation Array System", yet i t has been in use since 1971; and has proven through statist ics (over 4000 system-years), that the system when properly implemented wi l l prevent lightning strikes to the thus protected area.

Further, the present make up of the: "Technical Committee on Lightning Protection" contains many members who are opposed to the DAS, because of i ts potential impact on their business, or reputation. CO Q~_MITTEE ACTION: Reject. COMMITTEE STATEMENT: Proposal 78-63 (Log #11) was rejected, therefore, charge dissipation systems does not appear in the Code. See 78-63 (Log #1l).

(Log # 9) 78- 4 - (2-2): Reject SUBMITTER: Roy B. Carpenter, Jr., Lightning Eliminators & Consultants, Inc. RECOMMENDATION: Add:

Charge Dissipation. Charge Dissipation is an alternative lightning protection system wherein that system is designed to collect the charge induced on the earth by a charged storm cell , couple that charge to an air molecule ionizer, and fac i l i ta te the dissipation of that charge into the atmosphere through the ionized molecule mobility created by the storm cell charge. When proper charge dissipation has been accomplished, lightning strikes to the system and the thus protected site, wi l l be prevented; because the potential difference is too low. SUBSTANTIATION: The referenced NFPA Code makes no mention of the lightning protection system known as: "The Dissipation Array System", yet i t has been in use since 1971; and has proven through statist ics (over

4000 system-years), that the system when properly implemented, wil l prevent lightning strikes to the thus protected area.

Further, the present make up of the: "Technical Committee on Lightning Protection" contains many members who are opposed to the DAS, because of i ts potential impact on their business, or reputation. ~OMMITTEE ACTION: Reject. COMMITTEE STATEMENT: The proposal for charge dissipation was rejected in Proposal 78-63 (Log #11) therefore this system does not appear in the Code. See Proposal 78-63 (Log #1l).

78- 5 - (2-2): Accept SUBMITTER: Technical Committee on Lightning Protection RECQMMENDATION: Add the definition of "Combustible Liquid" as follows:

Combustible Liquid. A liquid having a flash point at or above lO0°F (37.8°C).

Combustible Liquids shall be subdivided as follows: Class I I liquids shall include those having flash

points at or above ]O0°F (37.8°C) and below 140°F (60°C(.

Class IIIA liquids shall include those having flash points at or above 140°F (60°C) and below 200°F (93°C).

Class IIIB liquids shall include those having flash points at or above 200°F (93°C). SUBSTANTIATION: Required due to the proposed new definition of Flammable Vapors. COMMITTEE ACTION: Accept.

78- 6 - (2-2): Accept SUBMITTER: Technical Committee on Lightning Protection RECOMMENDATIQN: Revise the definition of Flammable Vapors as follows:

Flammable Vapors. The vapors given off from a flammable or combustible liquid at or above its flash point. SUBSTANTIATION: The previous definition did not include combustible liquids (a liquid having a Flash point at or above 100°F). A flammable liquid is a l iquid having a flash point below 100°F. See NFPA 30 definitions. COMMITTEE ACTION: Accept.

78- 7 - (2-2): Accept SUBMITTER: Technical Committee on Lightning Protection BECOMMENDATION: In the definition of Stack, Heavy-duty, the word "and" in the third llne should be replaced with the word "or." SUBSTANTIATION: The original intent of this definition was that either condition exist in order that i t be defined as a heavy duty stack - not that both conditions exist. COMMITTEE ACTION: Accept.

(Log # 20) 78- 8 - (3-6): Accept in Principle SUBMITTER: Robert D. Harger, Harger Lightning Protection, Inc. RECOMMENDATION: Revise to read as follows:

"Precautions shall be taken to provide the necessary protection against any tendency towards deterioration of any lightning protection component due to local conditions. Copper components installed within 24 inches (0.6 m) of the top of a chimney or vent emitting corrosive gases shall be hot dipped lead coated." SUBSTANTIATION: This paragraph is revised to clarify i ts intent. The existing f i r s t sentence does not state what might deteriorate and the second sentence does not include "vents". This is important as i t may be more often that "vents" wi l l emit corrosive atmospheres. I t also suggests the hot dipped lead coating is on the chimney rather than the components.

354

COMMITTEE ACTION: Accept in Principle. Revise the last sentence to read: " . . :' corrosive gases shall be protected by a hot

dipped lead coating or equivalent." ~MMITTEE STATEMENT: The wording was revised to allow for other corrosion processes.

(Log# 21) 78- 9 - (3-9.1): Accept SUBMITTER: Robert D. Harger, Harger Lightning Protection, Inc. RECOMMENDATION: Revise to read as follows:

"The t ip of an a i r terminal shall be'not less than 10 in. (254 mm) above the object or area i t is to protect except as permitted by 3-11. See f igure (3-9LI) . " SUBSTANTIATION: This paragraph should be revised as the present wording does not provide for those cases where only one a i r terminal may be required. Or, for that matter, in those cases where a i r terminals may be required on a number of roof vent i la tors but not necessarily because of thei'r interval spacings. The height var ia t ion applies only to the increased spacing of a i r terminals and that is covered by 3-11. The intent of th is paragraph is that a l l a i r terminals must extend a minimum of I0 inches above'the area they are to protect. COMMITTEE ACTION: Accept.

Table 3- I I Air Terminal Spacing "-,

"A" "B" Height of Radius of Centers for Air Terminal Protected Z o n e SGuare SDacinq

I0" 15'0" 21'0" 12" 17'0" 24'0" 15" 18'0" 25'0" 18" 20'0" 28'0" 24" 23'0" • 32'0!' 36" 29'0" 41 '0" 48" 33' 0" - 46' 0" 60" 37'0" 52'0" 66" 40'0" 56'0" 72" 42'0" 59'0" 84" 44'0" 62'0" 96" " 47'0" 66'0"

~S_UBSTANTIATION: The use of a s t r i k ing distance has been applied to protecting of roofs since 1980 Edition. The same pr inc ip le should apply to location of a i r terminals to protect prominent roofs. The table a11ows for a safety factor of a minimum of two inches above plane of roof. COMMITTEE ACTION: Reject. COMMITTEE STATEMENT: The Committee is receptive to the concept of a i r terminal spacing based on s t r i k ing distance. The proposal is too general and changes need to be made to accommodate a l l types of structures.

(Log # 18) 78- I0 - (3-9.1): Accept in Principle SVBMITTER: H. G. VanSickle, A-C Lightning Secur'ity, Inc. RECOMMENDATION: New reworded paragraph:

3-9.1 HeighZ. The height of a i r terminals shall be such as to bring the t ip not less than I0 in. (254 mm) above the object to be protected. (See Figure 3~9.1). SUBSTANTIATION: The balance of proposals by this wr i ter for paragraphs 3-11 on a i r terminal spacing wil render the wording incorrect'. ' _~MMITTEE ACTIO_N: Accept in Principle. COMMITTEE STATEMENT:" See Proposal 78-9 (Log #21)~

(Log-# 2 2 ) 78- II - (Figure 3-9.1): Accept ~UBMITTER: Robert D. Harger, Harger Lightning Protection, Inc. RECOMMENDATION: Change "A" and "C" to read as follows:

"A" : 10 in. (254mm) See 3-9.1. : 24 in. (O.6m). See 3-11.

"C" Air terminal supports shall be located at a point not less than one hal f the height, of the a i r terminal. SUBSTANTIATION: These notes need to be revised inasmuch as we need to make i t clear that the minimum a i r terminal'heigh't above the area to be protected is 10 inches. The one exception is where a series of a i r terminals are spaced at 25 foot maximum intervals. In the case of "C", this is necessary as we now say a i r terminal supports must be "at" not less than one hal f the height of the a i r terminal when we rea l ly mean to say the POINT OF SUPPORT must be located so as to provide support for the a i r terminal at or'above i ts mid-point. COMMITTEE ACTION: Accept.

(Log # 13) 78- 12 - (3-11 and TaEle 3-11 (New)): Reject SUBMITTER: H. G. VanSickle, A-C Lightning .Security, Inc. RECOMMENDATION: Revise as fol lows:

3~II Air Terminals on Roofs. Ai r terminals shall be placed at or within 2 f t (0.6'm) of the ends of ' r idges or edges and corners of f l a t and gently sloping roofs. Air terminals shall be placed on ridges of pitched roofs and'around the perimet of f l a t or gently sloping roofs at intervals not exceeding the intervals allowed by a zone of protection based on a s t r i k ing distance of 150 f t . Table 3-11 may be used for quick calculations.

(Log # 14) 78- 13 - (3-11.1): Reject ~UBMITTER: H. G. ,VanSickle, A-C Lightning Security, Inc. RECOMMENDATION: Revise as fol lows:

3-11.1 Flat or Gently Sloping Roofs'. Gent ly sloping roofs are defined as: ( I ) those roofs having a span of 40 f t (12 m) or less and a pitch of less. than' I /8; and (2) those roofs having a span of more than 40 f t (12 m) and a pitch of less than I/4. Flat or gently sloping roofs with a width that exceeds the'zone of protection offered by the perimeter a i r terminals shall have addit ional a i r terminals place~ fo r tota l coverage. Table 3- I I column "A" may be used fo r c i rcu lar measurements or Table 3-11 column "B" may be used for square appl icat ion. SUBSTANTIATION: This correction follows the changes made in paragraph 3-11 to cover the center roof area of wide structures. CO_Q~_MITTEE ACTION: Reject. COMMITTEE STATEMENT: The Committee is receptive to 'the concept of a i r terminal spacing based on. s t r ik ing distance. The proposal is too general and changes need to be made to accommodate a l l types of structures.

(Log # 23') ' 78- 14 - (3 - I I . 2 ) : Accept SUBMITTER:" Robert D. Harger, Harger Lightning Protection, Inc. • RECOMMENDATION: In t h e f i r s t l ine delete "Prominent", "are" and "those" so that the paragraph begins: "Dorme'rs as ~igh or higher . . .

' In the f i f t h .line change "on a l l " to '"only on those". SUBSTANTIATION: -There seems to be no need to.define prominent dormers. The important consideration i s that i f they extend above the main ridge or i f they are outside a zone of protection they need to be protected. These changes are basical ly ed i t o r i a l . COMMITTEE ACTION: Accept.

(Log # 15) 78- 15 - (3-12): Accept in Principle SUBMITTER: H. G. VanSickle, A-C Lightning Security, Inc. RECOMMENDATION: Revise as follows:

3-12 Conductors. Conductorsshall interconnect a l l a i r terminals and shall form a two-way lath 'from each a i r terminal to connections with ground terminals. All paths shall maintain a generally horizontal or downward

355

direct ion with slopes of conductor runs not exceeding that allowable for gently sloping roofs in section 3-11.1.

Note exceptions permitted by 3-12.1 and 3-12.2. 3-12.1 Gently Sloping Conductors. Runs of conductor

interconnecting a i r terminals and ground terminals on the roof shall maintain as near a horzontal posit ion as is pract ica l . The maximum permitted slope of conductor shall not exceed that described in section 3-11.1. for gently sloping roofs. SUBSTANTIATe: The code in paragraph 3 -1 l . l allows gently sloping conductors on sloping roofs, but f i e ld conditions require a defined slope for conductors on f l a t or pitched roofs. The revised text makes the gradual sloping of conductors consistent. A new paragraph number must be assigned. COMM_ITTEE ACTION: Accept in Principle.

Revise the exist ing 3-12 in NFPA 78-1986 as follows: 3-]2 Conductors. Conductors shall interconnect a l l

a i r terminals and shall form a two-way path from each a i r terminal hor izonta l ly , downward, or r is ing at a rate not exceeding 3 inches per f t to connections with ground terminals except as permitted by 3-12.1 and 3-12.2. COMMITTEE STATEMEN__T: The proposed wording is d i f f i c u l t to apply therefore the revised wording is more easi ly applied in the real world.

(Log # 16) 78- 16 - (3-12.8): Reject SUBMITTER: H. G. VanSickle, A-C Lightning Security, Inc. RECOMMENDATION: Revise as fol lows:

3-12.8 Mid-Roof Conductors. Mid-roof conductors (main conductors) are required to interconnect the a i r terminals on f l a t or gently sloping roofs. Mid-roof conductors shall be connected to the main perimeter cable at in tervals not exceeding 150 f t (46 m). SUBSTANTIATION: This revision is required to be consistent with proposals fo r 3-1l. COMMMI_TTEE ACTION: Reject. COMMITTEE STATEMENT: The Committee is receptive to the concept of a i r terminal spacing based on s t r i k ing distance. The proposal is toogeneral and changes need to be made to accommodate a l l types of structures.

(Log # 24) 78- 17 - (3-12.13): Accept ~UBMITTER: Robert D. Marger, Harger Lightning Protection, Inc. RECOMMENDATION: Revise as follows:

3-12.13 Down Conductors and Structural Columns. Down conductors coursed on or in reinforced concrete columns or on structural steel columns shall be connected to the re inforc ing steel or the structural steel member at i t s upper and lower extremit ies. In the case of long ver t ica l members an additional connection shall be made at in tervals not exceeding 200 f t (60 m). Such connections shall be made using l i s ted clamps or bonding plates or by welding or brazing. The use of PVC conduit or other nonmetallic chase does not negate the need for these interconnections unless su f f i c ien t separation is provided to sat is fy the bonding requirements of 3-15, 3-16 and 3-17. Where such is not the case, provisions shall be made to assure the required interconnection of these para l le l ver t ica l paths. SUBSTANTIATION: I t is the intent of the code that these interconnections be made but there is no one place in the code where such a requirement is stated. Because i t has caused some concern, i t is suggested this be added to that section of the code dealing with down conductors. COMMITTEE ACTION: Accept.

(Log # 30) 78- 18 - (3-13 through 3-13.6, 3-14, 3-14.1): Accept ~UBMITTER: Robert D. Harger, Harger Lightning Protection, Inc. REqOMMENDATION: I. Renumber "3-13 thru 3-13.6" - "3-16 thru 3-16.6."

2. Renumber "3-14 and 3-14.1," "3-17 and 3-17.1" respectively. SUBSTANTIATION: This renumbering is required i f proposal regarding movingparagraphs 3-21 thru 3-22 forward is accepted. COMMITTEE ACTION: Accept.

78- 19 - (3-13 through 3-13.6): Accept SUBMITTER: Technical Committee on Lightning Protection RECOMMENDATION: The fol lowing changes to the referenced sections are as follows (complete text is shown:

Change the t i t l e of 3-13 to "Ground Terminals" to re f lec t the addit ion of two ground electrode types, the concrete encased electrode and ground ring electrode.

Add a th i rd sentence to paragraph 3-13.1 as noted. Renumber paragraph 3-13.2 and revise the language to

re f lec t current terminology. Renumber 3-13.3 and use "rods" in place of

"terminals." In the f i r s t sentence change "conductor" to "conductors."

Renumber 3-13.4 and use "rods" in place of "termi na] s."

Renumber 3-13.5. Renumber 3-13.6. Change "less" to "smaller." Delete ", where the measured . . . to provide

e f fec t ive grounding." and add a " . " at the end of the last sentence. Add reference to Figure 3-13.6.

Add the fol lowing new paragraphs: 3-13.2 Concrete Encased Electrodes. 3-13.2.1 Concrete Encased Electrode Terminations. 3-13.3 Ground Ring Electrode. 3-13.3.1 Ground Ring Electrode Terminations. 3-13.4 Combinations. Add to the end of the note in 3-16.1 "Ground Level Potential Equalization to allow use of

Ground Ring Electrode as a Ground Loop Conductor. A ground ring electrode conforming to 3-13.3 may be u t i l i zed fo r the ground loop conductor."

Add a de f in i t i on of Grounded. Grounded. Connected to earth or to some conducting

body that is connected to earth. Revised text to read as fol lows: 3-13 Ground Terminals. Each down conductor shall

terminate at a ground terminal. The design, size, depth, and number of ground terminals used shall comply with 3-13.1 through 3-13.4.

3-13.1 Ground Rods. Ground rods shall be not less than I/2 in. (12.7 mm) in diameter and 8 f t (2.4 m) long. Rods shall be copper-clad steel, sol id copper or stainless steel . Rods shall be free of paint or other nonconductive coatings.

3-13.1.I Ground Rod Terminations. The down conductor shall be attached to the ground rod by welding (including exothermic), brazing or clamping. Clamps shall be suitable fo r d i rect soi l bur ia l .

3-13.1.2 Deep Moist Clay Soil. The l ightning conductors or ground rods shall extend ve r t i ca l l y not less than lO f t (3 m) into the earth. The earth shall be compacted and made t ight against the length of the conductor or ground rod. (See Figure 3-13.4).

3-13.1.3 Sandy or Gravelly Soil. In sand or gravel, two or more ground rods, at not less than I0 f t (3 m) spacings, shall be driven ve r t i ca l l y to a minimum depth of lO f t (3 m) below grade. (See Figure 3-21.2).

3-13.1.4 Shallow Top Soil. Where bedrock is near the surface, the conductor shall be la id in trenches extending away from the bui lding at each down conductor. These trenches shall be not less than 12 f t (3.7 m) in length and from l to 2 f t (0.3 to 0.6 m) in depth in clay so i l . In sandy or gravel ly so i l , the trench shall be not less than 24 f t (7.5 m) in length and 2 f t (0.6 m) in depth. I f these methods should prove impractical, an accepatable a l ternat ive would be to carry the l ightning protect in cable in tenches, of a depth specif ied above, or i f th is is impossible, d i rec t ly on bedrock a minimum distance of 2 f t (0.6 m) from the foundation or ex te r io r foot ing and terminate by attachment to a buried copper ground plate at least 0.032 in (0.8 mm) thic~ and having a minimum surface area of 2 sq f t (0.18 m~).

3-13.1.5 Soil Less than One Foot (0.3 m) Deept. I f the soi l is less than one foot (0.3 m) in depth, down conductors shall be connected to a loop conductor

356

installed in a trench or in rock crevices around the structure. The loop conductor shall be not smaller than tile equivalent of a main size l.ightning .. conductor. Optional plate electrodes may be attached to the loop conductor to enhance its earth contact, where the measured grounding resistance is found to be too high to provide effective grounding. (See Figure 3-13.6).

3-13.2 Concrete Encased Electrodes. Concrete. encased electrodes shall only be used in new construction. The electrode shall be loEated near the bottom of a. concrete foundation or footing that is in direct contact with the earth and shall be encased by not less than 2 in. (50.8 mm) of concrete. The encased electrode shall consist of:

Ca) Not less than 20 f t (6.1 m) of No. 2 AWG bare copper conductor.

(b) An electrode consisting of at least 20 f t (6.1 m) of one or more steel reinforcing bars or rods not less than I/2 in. (12.7 mm) in diameter that have been effectively bonded together by either welding or overlapping 20 diameters and securely wire tying.

3-13.2.1 Concrete Encased Electrode Terminations. The down conductor(s) shall be permanently attached to the concrete encased electrode system by welding (including exothermic), brazing or clamps.

3-13.3 Ground Ring Electrode. A ground ring electrode encircling a structure shall be in direct contact with earth at a depth of not less than 2-I/2 f t (762 mm) or encased in a concrete footing in accordance with 3-I,3.2. I t shall consist of not less than 20 continuous feet (6.1 m) of No. 2 AWG bare copper- conductor.

3-13.3.1 Ground Ring Electrode Terminations. The down conductor(s) shall be permanently attached to the ground ring electrode by welding (including exothermic), brazing or clamps. Clamps shall be suitable for direct burial.

3-13.4 Combinations. Combinations of the above grounding terminals is permitted. SUBSTANTIATION: Concrete encased electrodes and ground ring electrodes are recognized by the National Electrical Code, NFPA 70, Articles 250-81(c) and 250-81(d). Paragraphs 3-13.2 through 3-13.6 are renumbered to accommodate the inclusion of paragraphs to describe the concrete encased electrodes and ground ring electrodes and their terminations.

Paragraph 3-13 t i t l e requires a change to reflect the addition of the concrete encased electrode and the ground ring electrode.

Renumbered paragraph 3-13.1, added corrections and additional sentence reflects current technology.

Renumbered paragraph 3-13.1.2 changes reflects current terminology.

Renumbered paragraph 3-13.1.3 changes reflects current terminology.

Renumbered paragraph 3-13.1.5 changes are to comply with acceptable style per the Style Manual.

New paragraph 3-13.2 incorporates the description of the concrete encased electrode.

New paragraph 3-13.2.1 incorporates the description • of the termination to the concrete encased electrode.

New paragraph 3-13.3 incorporates the description of the Ground Ring Electrode.

New paragraph 3-13.3.1 incorporates the description of the termination to the ground ring electrode.

New paragraph 3-13.4 describes a method to use a combination the above method.

The five new paragraphs are derivations from the National Electrical Code modified to reflect the practices of the industry.

The additional note to paragraph 3-16.1 allows the use of the ground ring electrode as a ground loop conductor eliminating a possible duplication.

Grounded is an undefined term which is used extensively in paragraph 3-16. COMMITTEE ACTION: Accept.

78- 20 - (3-14): Accept SUBMITTER: Technical Committee on Lightning Protection RECOMMENDATION: Insert following text before the last sentence:

"Interconnection to a gas line shall be made on the customer's side of the meter."

SUBSTANTIATI__ON: To c lar i fy location of bond to Lightning Protection System to conform with the requirements of 192.467 of Minimum Federal Safety Standards for Gas Lines (Part 192, Ti t le 49, Code of Federal Regulations. COMMITTEE ACTION: Accept.

(Log # 6) 78- 21 - (3-14, 3-14.1, and 3-18): Reject SUBMITTER: George Sickel, Winchester, IN R__E~OMMENDATION: Rewrite 3-14, 3-14.1 and 3-18 to eliminate the dependence on a metal waterpipe for a grounding electrode. Metal waterpipes should be taken care of in National Electrical Code 70-1987, Section 250-44. A copy of my version of the rewrite is included.

NOTE: Supporting material available for review at NFPA Headquarters.

SUBSTANTIATION: The use of plastic for installations, replacement and repairs, can render a metal water pipe useless as a grounding conductor, when they are isolated with plastic they become, Isolated (Nongrounded) Metallic Bodies 3-17.3.

They belong in National Electric Code 70-1987, Section 250-44, Nonelectric Equipment, which may become energized.

In buildings occupied by people and livestock, i t is safer to bond them to a 120/240 volt , 200 amp electric system than to bond to a lightning conductor and inject them with 2,000,000 volts and I00,000 amps or more.

Equal Potential obtained in 3-16. COMMITTEE ACTION: Reject. COMMITTEE STATEMENT: A water pipe is not recognized as a ground in NFPA 78.

78- 22 - (3-1d.I): Accept SUBMITTER: Technical Committee on Lightning Protection I RECOMMENDATION: Change the word "grounded" to "bonded" in the f i r s t sentence. SUBSTANTIATION: Intent is not for items to be grounded through a metal water pipe, but instead bonded to the metal pipe. COMMITTEE ACTION: Accept.

78- 23 - (3-15 thru 3-17): Accept SUBMITTER: Technical Committee on Lightning Protection RECOMMENDATION: Revise as follows:

3-15 I t is recon~nended the following phrase, beginning in the fourth l ine be deleted, "Or because they may effect the bonding requirements for other metal bodies.

3-15.1(c) Rewrite as follows:• "Bonding distance requirements depend on a technical

evaluation of the number of down conductors and their location, the interconnection of other grounded systems, the proximity of grounded metal bodies to the down conductors, and the flashover medium (i .e. a~r or solid materials).

3-17.I(a) and (b): Add at beginning of sentence: "Grounded and nongrounded" Add at end of sentence: "At these locations." 3-17.1(c) Add after "Bonding of": "Grounded or ungrounded." Delete all after "Determined by" and add: "3-17.2 and 3-17.3 respectively." 3-17.2 Rewrite second sentence as follows: "Where grounded metal bodies have been connected to

the lightning protection system at only one extremity, the following formula shall be used to determine i f additional bonding is required."

Rewrite third sentence as follows: "Branches of grounded metal bodies connected to the

lightning protection system at their extremities shall require bonding to the lightning protection system in accordance with the following formula i f they change vertical direction more than 12 feet (3.6 m).

NOTE: Where such bonding has been accomplished either inherently through construction or by physical contact between electr ical ly conductive

357

materials, no addit ional bonding connection is required.

3-17.2(a) and (b) Change the formula to: D = h K m

6N In the f i r s t l ine under the formula delete the word

"from" and i t s place add: "Between the bond being considered and". Also, place a period a f te r "System bond" and delete "Described in Section 3-16."

Following the de f in i t i on of "n" add: K m = 1.0 i f the flashover is through a i r or 0.50 i f ~hrough dense material such as concrete, brick, wood, etc.

3-17.2(a) In the th i rd sentence fol lowing "located" change "less than" to "within a zone of" .

3-17.2(a)(2) F i rs t l ine:. Delete "the" and add "a leve l " .

Second Line': 'Delete " leve l " and add " to ta l " between "the" and "number".

Third Line: Delete " th is zone" and add "the l ightning protection system".

3-17.2(b) In the sentence d i rec t l y under the formula delete a l l a f te r "nearest" and add "bonding connection from the grounded metal body to the l ightning protection system and the point on the down conductor where the bonding connection is being considered.

3-17.2(c) Second sentence fol lowing formula change "less than" to "within a zone of" .

3-17.3 I. Delete "less than 60 f t (18 m) in ver t ica l height.

2. Eighth l ine - f i r s t paragraph change "another" to "the".

3. Fourth l ine second paragraph, change "A" to "The." SUBSTANTIATION: 3-15 - The part of the sentence is redundant since the "ef fect ' on bonding" is covered by preceding part of sentence.

3-15.1(c) - The rewording is proposed to c l a r i f y the factors taken into consideration for bonding and to add consideration of the f lashover medium. Appendix "k" makes reference to the intensi ty of e lec t r i c f ie lds in d i f fe ren t media.

3 -17 . I (a ) and (b) - To make clear the fact that both grounded and ungrounded metal bodies shall be considered.

3-17.1(c) - Same as above. Addition of reference'to "3-17.3" necessary for ungrounded metal bodies.

3-17.2 - Due to opportunity for various interpretat ions and need to be de f i n i t i ve second and th i rd sentences revised and note added. The need exists for examination of grounded metal bodies where they r ise through a structure.

The use of "d i f fe ren t elevation" in the th i rd sentence was too general.

The note is added so as not to require a separate bonding connection when bonding has been done through construction.

3-17.2(a) and (b) - The bonding distance "D" is affected by the medium through which a sideflash may occur. Since a i r is the least resistant the factor 1.0 should apply. Other substances used in construction such as concrete, brick, wood and plast ics impede the developmen~ of an e lec t r ica l f i e l d . A reduction in value should be made. An average factor of 0.50 appears to cover the insulat ing e f fec t .

3-17.2(a) - The rewording better describes the location of down conductors to be considered.

3-17.2(a) and (z) - The rewording clears up the fact that "n" is a number equal to the tota l Lightning Protection System down conductors.

3-17.2(b) - Revised language needed to better define the value of "h" when not the tota l height of the structure.

3-17.2(b) - Same as 3-17.2(a). 3-17.3 - I. The tota l paragraph covers ungrounded

metal bodies regardless of the i r height. 2. Corrects the meaning of the sentence so a second

grounded metal body is not considered. 3. Cleary directs the reader to the grounded metal

body under consideration. COMMITTEE ACTION: Accept.

(Log # 42) 78- 24 - (3-15 thru 3-17.3 and 3-20): Accept ~UBMITTER: Robert D. Harger, Harger Lightning Protection, Inc. RECOMMENDATION: I. Renumber paragraphs 3-20, 3-15, 3-15.1, 3-15.2, 3-16, 3-16.1, 3-16.2, 3-16.3, 3-17, 3-17.1, 3-17.2, and 3-17.3 to 3-21, 3-22, 3-22.1, 3-22.2, 3-23, 3-23.1, 3-23.2, 3-23.3, 3-24, 3-24.1, 3-24.2 and 3-24.3 respectively. SUBSTANTIATION: This renumbering is necessary to correct paragraph numbering i f previous proposals concerning the reloacting of certain sections within the code are accepted. COMMITTEE ACTION: Accept.

(Log #4) 78- 25 - (3-16.1): Reject SUBMITTER: Harold G. VanSickle, A-C Lightning Security, Inc. RECOMMENDATION: Revise f i r s t paragraph to read: .

3-16.1 Ground Level Potential Equalization. All grounded media in and on the structure shall be connected to the l ightning protection system down conductors or groundings at the lowest practical point in accordance with 3-22. SUBSTANTIATION: The f igure "12 f t " would not allow for the r e t r o f i t i ns ta l l a t i on of a l ightning protection' system on many buildings without enormous increases in cost. COMMITTEE ACTION: Reject. COMMITTEE STATEMENT: The 12 f t distance is based on the formula in 3-17.2 and discussion in Appendix K developed for determining equal potential bonding distance.

(Log # 44) 78L 26 - (3-18): Accept SUBMITTER: Robert Harger, Harger Lightning Protection, Inc. RECOMMENDATION: Delete this paragraph in i ts~ent i re ty . SUBSTANTIATION: I. The present text is neither ~' technical ly nor grammatically c o r r e c t .

2. The reference to 3-16 is incorrect as no metal bodies are "described in 3-16."

3. The reference to bonding via structural steel connections is more c lear ly addressed in 3-15.1..

4. This text material is adequately covered in Sections 3-14 thru 3-17, par t i cu la r ly 3-14.1. COMMITTEE ACTION: Accept.

(Log # 17) 78- 27 - (3-18): Reject }UBMITTER: H. G. VanSickle, A-C Lightning Protection Security, Inc. RECOMMENDATION: Revise as fol lows:

3-18 Water Pipe Bond. I f a metal water pipe system is present and the l ightning conductor has been bonded to the water pipe, then the metal bodies described in Section 3-17 shall be connected e i ther to the metal water pipe system, the nearest l ightning conductor, or to another metal body already connected to the system. Where other metal bodies are bonded through the i r structural connection to the metal water pipe system at each functional level of a building, no additional bonding is required. }_VBSTANTIATION: The metal water piping system within a structure is interconnected to other grounded systems at equipment housings, f i x tu res and metal supports during normal construction. When these interconnections can be ver i f ied , there is no need for addit ional bonding. COMMITTEE ACTION: Reject. COMMITTEE STATEMENT: This information is already adequately covered in other sections of the Code.

358

' (Log # 41) 78- 28 -~(3-ig): Accept in Principle SUBMITTER: Robert.>D. Harger, Harger'Lightning _ Protection, Inc.

l i RECOMMENDATION:-. I. Change the heading to: "Antenna M ~ ; o r t s . " ,""

2. vRewrite the paragraph to read as follows: '.,"Metal antenna masts or supports located on or adjacent to a protected structure shall be connected to the l ightning protection system using main s•ize conductors and l isted ,f i tt ings. unless-they are within a zone of pFotection".

~, 3, Renumber the paragraph• 3-.20. ~,. ~UBSTANTIATION .,The heading should be changed because

the paragraph deals speci f ica l ly with the interconnection of antenna masts and supports.

The proposed rewrite of this paragraph is basically edi tor ia l but adds antenna supports as might be encountered with dish type antennas, etc.

The renumbering of the paragraph is necessary i f other proposals are accepted. COMMITTEE ACTION: Accept in Principle.

Add "metal" to heading: "Metal Antenna Masts and-Supports" . . . .

', Delete "or adjacent to" from the proposal. COMMITTEE STATEMENT: "Metal" was added to the heading to define the type of mast and support, l~Or adjacent to" was deleted because this term ,is vague and undefined.

• ! 78- 29 -.:(3-20.): Reject . (Log #.19),, S UBMITTER:. Lawrence C. Keaton, •System Engineering Laboratories of Northwest Texas RECOMMENDATION: Delete current wording. SUBSTANTIATION: Current specification does not adequatel~ cover the requirements.for the scope of surge •suppression in lightning' protection systems and provide minimum response time for suppressor equipment.

, NOTE: Supporting material is available for review at NFPA Headquarters. ,~,

COMMITTEE ACT.ION: ,,Reject. COMMITTEE STATEMENT: The intent of, this Code is for protection of the structure and the section has been c lar i f ied by the Committee in Proposal 78-30.

78- 30 - (3-20): Accept SUBMITTER: Technical Committee on Lightning Protection RECOMMENDATION: Revise 3-20 as follows:

3-20 "Lightning,'arresters, and Protectors. Lightning arresters and protectors, shall be instal led on electr ic and telephone service entrances and on radio and television antenna lead-ins to provide protection f~or the s t r u c t u r e .

NOTE: Certain electr ical systems or components within the structure'may require further l ightning protection. Such protection requi.rements are not a part of ,this Code.'

SUBSTANTIA~IQN: To c la r i f y the intent of this section that NFPA 78 pertains to protectin of the structure. COMMI,TTEE AOTION: Accept.

(Log"# 26) 2 78 - 31 - ( 3 - 2 1 ) : A ccep t SUBMITTER: Robert O. Harger, Harger Lightning Protection, Inc. RECOMMENDATION: Change the heading to "Conductor Fasteners" and delete the words "building, or other object" in the second l ine and replace with the word "structure". SUBSTANTIATION: This paragraph deals'with'conductor fasteners as opposed to fasteners (nails, screws, bolts, etc.) in. general and should be so ident i f ied in the heading. The minor edi tor ia l change proposes using the word structure inasmuch as i t has been agreed "structure" includes buildings, • objects, forms, shapes, etc.

,CO MMI, TTEE ACTION: Accept.

• ( L 6 g : # 25); - 78 - 32 - ( 3 - 2 1 , 3 - 2 1 . 1 and 3 - 2 2 ) : A~cep t . . . .

• SUBMITTER: Robert D. Harger, Harger Lightning Protection, Inc. "' '~", RECOMMENDATION: Renumber paragraphs 3-2i " 3-21.1 and 3-22; - 3-13, 3-14, and 3-15, respectively. This renumbering wi l l necessitate some 'additional , : renumbering of paragraph's" and thesewi l l be handled by subsequent proposals. SUBSTANTIATION: Those three paragraphs deal d i rect ly with conductors and accordingly would be better placed in the code following Section 3-12 dealing with conductors. . COMMITTEE ACTION: Accept.

- - ' ' t

'~:' ' ( L o g # 27) .: 78- 33 - (3-21.1): Accept in Principle S__U_BMITTER: Robert D. Harger, Hafger Lightning .Protection, Inc. ,, , " '~ . RECOMMENDATION: Change the heading to "Masonry Anchors!' and rewrite the paragraph to read,'as'follows:

• "Masonry anchors used to secure l ightning protection materials shall have a minimum outside, diameteP'of not l:ess than I /4 in. (6.4 mm) and shall be seti'with,care. Holes made to receive the body of the anchor,shall be of the correct size, made with the proper tools, and preferably made in the brick, stone, or other masonry unit rather than in mortar jo ints. When the anchors are instal led the f i t shall be t ight against moisture thus reducing the possib i l f ty of damage"due to " freezing." , ' , SUBSTANTIATION: This paragraph deals solely w f t h masonry anchors asopposed to other types6T~anchors * and. should be so t i t l ed . Minor edi tor ia l changes were made to correct sentence structure and/o~ to c la r i fy I the intent of the' paragraph. ' COMMITTEE ~CTION: Accept in,Pr'inciple. -•,"

Delete'"not less than" from the f i ' rst sentence• COMMITTEE STATEMENT: 'Delete this phrase because i t is redundant. ..~

/(LOg '# 12) ':':: 78- 34'- (3-21.5 (New),): A~cept in.PrinCiple ( " SUBMITTER: J. K.Daugherty, F l in t , HI ' ' " ': RECOMMENDATION: Add the following new pa.rag,~aphv

3-21.5 Concrete-Encased. Electkode'. ':An electrode encased by at least 2 in. '(50'.8 mm) of concrete," located within and near the bottom of a concrete foundation or footing that is in direct contact with the earth, encircl ing the foundation with provisions for connecting al l down conductors, consisting of at least 20 f t (6.1 m) of one or more steel reinforc!ng bars or rods of not less"than I/2 in.' (12.7 mm) diameter, or consisting'of at least 20 f t (6.1 m) "of ,bare copper.'condu'ctor not smaller than ~No. 4 AWG. SUBSTANTIATION: 'The system has been ih use in Arizona

• since 1941. The-system wasRsuccessfully subjected to performance tests 'at the Los'Angeles Department of- Water and Power in 1964 which preceded the introduction of this system to the 1968National Electrical Code. The system has' been widely used in Europe and is proposed for the IEC Lightening Prot'ection Code. Supporting material provided with Proposal No.'78-55 in

1 9 8 5 . C__0HMI_TTEE'ACTION: A c c e p t i 'n ~ P r i n c i p l e . COMMITTEE STATEMENT':- See Commi' t tee P r o p o s a l 7 8 = 1 9 Commi t tee P r o p o s a l i n c l u d e s t h l s m a t e r i a l .

(Log'~i) 78- 35 - (3-2I.5 (New)): Accept in'Principle. SUBMITTER: William C. Brbderick',:Meyer~Strong &/Jones P.C. . .': ..... r ' 't: RECOMMENDATION: We recommend strongly that . th is ' proposal-(78-55 of the 1986 Annual Meeting TCR) be accepted. SUBSTANTIATION: Tests perfdrmed independently ~y,. several authorit ies show that this method of grounding is never poorer that normal "man made"electrodes'. This method is approved by NFPA.70.- We also enclose as

359

substantiation two articles published by the IEEE, the original by Mr. Ufer in 1964 and subsequent tests performed by Messrs Fagan and Lee published in 1970.

NOTE: Supporting material is available for review at NFPA Headquarters."

~_QHMITTEE ACTION: Accept in Principle. COMMITTEE STATEMENT: See Committee Proposal 78-19 Committee proposal includes this material.

(Log #2) 78- 36 - (3-21.5 (New)): Accept in Principle SUBMITTEd: J. K. Daugherty, Flint, MI RECOMMENDATION: Proposal No. 78-55 of the 1986 Annual Meeting TCR should be accepted. SUBSTANTIATION: The concrete-encased electrode has been proven acceptable beyond a reasonable doubt through use since 1941 and tests at the Los Angeles Department of Water and Power in 1964. The system is widely used in Europe and is a part of the proposed IEC, TC 81 Standard for Lightning Protection. I question the referal of this proposal to the Earth Termination Subcommittee when none exists. COMMITTEE ACTI_Lq~: Accept in Principle. COMMITTEE STATEMENT: See Committee Proposal 78-19. Committee proposal includes this material.

(Log # 28) 78- 37 - (3-22): Accept SUBMITTER: Robert D. Harger, Harger Lightning Protection, Inc. RECOMMENDATION: Change the heading to "Connector Fittings" and rewrite the paragraph to read as follows:

"Connector f i t t ings shall be used at al l "end to end", "tee", or "y" splices of lightning conductors. They shall be attached so as to withstand a pull test of 200 Ibs (890N). Fittings used for required connections to metal bodies in or on a structure shall be secured to the metal body under bolt tension. Conductor Connections shall be of the bolted, welded, high compression, or crimp-type except that crimp-type connections'shall not be used with Class I I conductors." SUBSTANTIATION: This paragraph deals with FITTINGS used to connect conductors together or to certain metal bodies and i t is fe l t the paragraph should be so headed. Minor editorial changes were made to clar i fy the intent of the paragraph. COMMITTEE ACTION: Accept.

(Log #3) 78- 38 - (3-22): Accept in Principle S~BMiTTER: Larry T. Ingels, American Gas Association EE~OMMENDATION: Add to Section 3-22: ' 3-22 Common Grounding. All grounding mediums shall Ee, bonded together. This shall include lightning protection, electric, telephone, antenna system grounds and underground metallic p.iping systems which enter the structure. Such piping systems include lightning protection, water service, well casings within 25 f t (7.6 m) of the protected structure, gas piping, underground conduits, underground liquefied petroleum-gas piping systems, etc. Main size conductors shall be used for bonding other grounding systems to the lightning protection system. Attachment of qrovnd wires from a liah~nina protection system to a natural_]__qas pjj~.eline or se!!ice violates 192.467_of Minimum Federal Safety Standards for Gas Lines (Part 192, Tit le 49, Code oF Federal Reaulations). Customer gas p~pinq downstream of the m__e_~ter is exempt from 192.467. Contact the local natvral qas company for specific det_ails. SUB~TAHTIATIQ~_: Gas u t i l i t i es are finding attachments of lightning grounding cables to metallic services. This attachment causes a short and nul l i f ies the cathodic protection system which is required by Federal Regulations. COMMITTEE ACTION: Accept in Principle. COM___MMITTEE STATEMENT: See Committee Proposal 78-20. Committee proposal addresses the submitter's concerns regarding the customer side of the gas pipeline.

(Log # 29) 78- 39 - (3-23): Accept SUBMITTER: Robert D. Harger, Harger Lightning Protection, Inc. RECOMMENDATION: Delete this paragraph in i ts entirety. SUBSTANTIATION: This paragraph serves no useful purpose. In most cases i t is d i f f i cu l t to know i f a new system may "require" future testing. One would hope that al l lightning protection systems are tested periodically, however that does not just i fy the installation of disconnect f i t t ings on all but one ground terminal on every installation. Provisions for testing or supplying disconnect f i t t ings should be the responsibility of the design engineer. COMMITTEE ACTION: Accept.

(Log # 5) 78- 40 - (3-23): Accept in Principle SUBHITTER: Necati Ergan, Ministry of Interior, GDP, Design Dept., Saudia Arabia RECOMMENDATION: Revised text:

3-23 Bonding of Metal Bodies. Certain metal bodies located outside or inside abui lding contribute to lightning hazards because they.are grounded or assist in providing a path to ground for lightning currents. Such metal bodies shall be directly bonded to the lightning protection system and series-connections through bodies shall not be allowed. These metal bodies are further defined as primary or secondary metal bodies in 3-23.1 and 3-23.2. ~UBSTANTIATION: In practice some contractors and also project engineers are choosing this easy way in which metal bodies are bonded through each other - in series - to the lightning protection system (in certain cases to the their grounding system) without knowing the importance of this point. Because such series - connections have to be broken during any repair or maintenance work on one of the series-connected units. May be these people making this mistake are considering the air terminals connected likewise. COMMITTEE ACTION: Accept in Principle. COMMITTEE STATEMENT: See Committee Proposal 78-23.

Even though the submitter addressed the 1983 edition when the present edition is 1986, the Committee addressed this subject in Committee Proposal 78-23.

(Log # 31) 78- 41 - (3-24): Accept SUBMITTER: Robert D. Harger, Harger Lightning Protection, Inc. RECOMMENDATION: I. I t is proposed this section on concealed systems be renumbered and moved forward in the code; following the paragraph on Common Grou~id Bondings.

2. New paragraphs with heading only - 3-18 "Concealed Systems".

3. Change heading of 3-24 to "General". 4. Renumber 3-24, thru 3-24.3 to 3-18.1 thru 3-18.4.

SUBSTANTIATION: I t is fe l t this section is quite important and because of the code paragraph numbering and heading system i t really has become "lost" in the code. Also, i t appears to be more logical that this information follow the code requirements for "exterior" system components and before the requirements for potential equalization (bonding). COMMITTEE ACTION: Accept.

(Log # 32) 78- 42 - (3-24.1): Accept in Principle SUBMITTER: Robert D. Harger, Harger Lightning Protection, Inc. RECOMMENDATION: I. Change the heading to "Masonry Chimneys".

2. Rewrite the paragraph to read as follows: "Chimney air terminals and conductors shall be

permitted to be bui l t into masonry chimneys or to be attached to the exterior of masonry chimneys and routed thru the structure to concealed main conductors".

NOTE: Another proposal requests this paragraph to be renumbered, 3-18.2.

360

SUBSTANTIATION: This paragraph deals with Masonry Chimneys only and should be so headed. Minor editorial changes made to more correctly state the intent of the paragraph. COMMITTEE ACTiq_N: Accept in Principle. :

Change "bui l t into" to "concealed within." COMMITTEE STATEMENT: Editorial.

(Log # 8) 78- 43 - (3-24.2): Reject }UBMITTER: Nicholas A. Legatos, American Concrete Institute RECOMMENDATION: Add the •following sentence at the end of paragraph 3-24.2:

"The reinforcing steel bar(s) thus bonded to the embedded cable shall be made electr ical ly continuous between points of contact with the cable. Continuity shall be achieved by such means as wil l ensure direct, firm and secure contact between the connected bars. Prestressing reinforcement and other prestressing elements shall not be used as conductors, and shall be located remote from embedded cables." SUBSTANTIATION: I. Bar connections must be firm and tight so as to prevent the connected bars from separating. I f a gap forms between these bars, the electrical charge passing through the bonded bar may jump across the gap damaging the surrounding concrete.

2. As prestressing reinforcement, anchorages, etc. are always in a state of high stress, i t is inadvisable to ut i l ize them as conductors. COMMITTEE ACTION: Reject. COMMITTEE STATEMENT: The proposer did not supply sufficient data to substantiate the recommendation, therefore the Committee could 'not vote affirmatively.

(Log # 33) 78- 44 - (3-24.2): Accept SUBMITTER: Robert D. Harger, Harger Lightning Protection, Inc. REC~MENDATION: I. Change the heading to'"Concealment in Steel Reinforced Concrete".

2. Rewrite the paragraph to read as follows: "Conductors or other components of the lightning

protection system concealed in steel reinforced concrete units shall be connected to the reinforcing steel. Concealed down conductors shall be connected to the vertical reinforcing steel in accordance with 3-12.13. Roof conductors or other concealed horizontal conductor runs shall be connected to the reinforcing steel at intervals not exceeding I00 f t (30 m)." SUBSTANTIATIQN_: This paragraph deals with STEEL REINFORCED concrete. Concrete which is not reinforced or reinforced with nonconducting media does not apply. Therefore the concern is with the steel reinforcing and not the concrete. I t is rewritten to more correctly express the intent of the paragraph.

Note: Another proposal requests this paragraph to be renumbered 3-18.3 and the above referenced paragraph number 3-12.13 is a new paragraph proposed by submitter. COMMITTEE ACTION: Accept.

(Log # 34) 78- 45 - (3-2a.3): Accept SUBMITTER: Robert D. Harger, Harger Lightning Protection, Inc. RECOMMENDATION: 1. Change the heading to "Ground Terminals" -

2. Rewrite the paragraph to read as follows: "Ground terminals for concealed systems shall comply

with Section 3-13. Ground terminals located under basement slabs or in crawl spaces shall be installed as near as practicable to the outside perimeter of the structure. Where rod or cable conductors are used for ground terminals, they shall be in contact with the earth for a minimum of I0 f t (3m) and shall extend to a depth of not less than 10 f t (3m) below finished grade except as permitted by 3-13.3 and 3-13.4." SUBSTANTIATION: A rewrite is necessary because the text used the words " i f " and "may". Also proposed wording more specifically states the requirements of this section.

Note: Another proposal by submitter proposed the renumbering of this paragraph to 3-18.4 and the referenced paragraphs are proposed to be 3-16.5 and 3-16.6 respect~yely. COMMITTEE ACTION: Accept.

(Log # 35) 78- 46 - (3-25)i Accept SUBMITTER: Robert D. Harger, Harger Lightning Protection, Inc. RECOMMENDATION: I. I t is proposed this section be renumbered and moved forward in.the code, following the section on concealed systems which is the subject of another proposal by this submitter.

2. New paragraph with heading only ~ 3-19 "Structural Steel Systems".

3. Change heading of 3-25 to "General" and in the second line change "building" to "structure".

4. Renumber 3-25 thru 3-25.4 to 3-19.1 thru 3-19.5. SUBSTANTIATION: This proposal is intended to make structural steel systems and their special requirements more visible in the code. Also by moving i t forward in the code i t is more "visible" as i t is not "hidden" behind equal potential bonding requirements. Changing building to structure is only editorial and is in keeping with the Committee's view that buildings are structures. COMMITTEE ACTION: Accept.

(Log # 36) 78- 47 - (3-25.1): Accept SUBMITTER: Robert D. Harger, Harger Lightning Protection, Inc. RECOMMENDATION: I. Change the paragraph to read:

"Air terminals shall be connected to the structural steel framing by direct connection, by use of individual conductors routed through the roof or parapet walls to the steel framework, or by use of an exterior conductor that interconnects all air terminals and which is connected to the steel framework. Where such an exterior condutor is used i t shall be connected to the steel framework of the structure at intervals not exceeding 100 f t (30m)." SUBSTANTIATION: Editorial changes for clarif ication only.

Note: This paragraph wil l be renumbered 3-19.2.1f other proposal is accepted. COMMITTEE ACTION: Accept.

(Log # 37) 78- 48 - (3-25.2): Accept in Pr inc ip le ~UBMITTER: Robert D. Harger, Harger Lightning Protect ion, Inc. RECOMMENDATION: l . Change the heading to:

"Connections to Framework". 2. Rewrite the paragraph to read: "Conductors shall be connected to cleaned areas of

the structural steel framework by use of bonding plates having a_surface contact area of not less than 8 sq in. (5200 mm Z) or by welding or brazing. Bonding plates shall have bolt tension cable connectors and shall be bolted, welded, or brazed securely to the structural steel framework so as to maintain electrical continuity." SUBSTANTIATION: The heading should be changed inasmuch as the paragraph deals only with connections to steel framework and not with typical splice connection, etc.

Editorial changes are for clar i f icat ion purposes and to permit welding conductors directly to steel members.

Note: Another proposal by this submitter requests this paragraph be renumbered 3-19.3. COMMITTEE ACTION: Accept in Principle.

Change "tension" to "pressure." COMMITTEE STATEMENT: The change is for consistency of terms in NFPA 78.

361

(Log # 38) 78- 49 - (3-25.3): Accept in Principle SUBMITTER: Robert D. Harger, Harger Lightning Protection, Inc. RECOMMENDATION: I. Change the heading to: "Ground Terminals."

2. Rewrite the f i r s t two sentences of this paragraph to read as follows:

"Ground terminals shall be connected to approximately every other steel column around the perimeter of the structure at intervals averaging not more than 60 f t (18 m). Connections shall be made to cleaned areas near the base of the column by use of a bonding plate having a surface contact area of not less than 8 sq in. (5200 m), or by welding or brazing the ground terminal conductor d i rect ly to the column. Bonding plates shall have bolt tension cable connectors and shall be bolted, welded, or brazed securely to the column so as to maintain electr ical cont inuity." SUBST_ANTIATIQN: The heading should be changed inasmuch as the paragraph deals with ground terminals and their attachment to the structure.

Other changes are edi tor ia l and are needed for c lar i f ica t ion of the intent of the paragraph. COMMITTEE ACTION: Accept in Principle.

Change the second sentence of the proposal to read: "Connections shall be made near the base of the

column in accordance with 3-2.5.2." Delete the remainder of the paragraph.

~ITTEE__$TATEMENT: Tile requi rement is already covered in 3-2.5.2 therefore the paragraph was revised.

(Log # 40) 78- 50 - (3-25.4): Accept in Principle SUB__MITTER: Robert D. Harger, Harger Lightning Protection, Inc. RECOMMENDATION: I. Change the heading to:

"Bonding Connections." 2. Rewrite the paragraph to read as follows: "Metal bodies located within a steel framed structure

may be inherently bonded to the structure "through construction. In such cases separate bonding connections shall not be required". SUBSTANTIATION: The heading should be charged because the paragraph deals speci f ical ly with bonding connections.

The edi tor ia l changes in this paragraph do not change the intent but submitter feels they help to c la r i fy the intent which is to recognize those metal bodies which are inherently bonded to the structural framework because of the manner in which they are secured to the framework. COMMITTEE ACT_.ION: Accept in Principle.

Change to read as follows: "Where metal bodies located within a steel framed

structure are inherently bonded to the structure through the construction, separate bonding connections shall not be required." COMMITTEE STATEMENT: Editorial c la r i f i ca t ion .

78- 51 - (4-3 and Chapter 7): Accept SUBMITTER: Technical Committee on Lightning Protection RECOMMENDATION: Delete last sentence of this section:

"For protection . . . Preparation Plants." Remove referencs from Chapter 7.

S_UBSTANTIATION: A reference to protection from hazards other than l ightning is not necessary to this code. COMMITTEE ACTION: Accept.

(Log # 7) 78- 52 - (4-6 (New)): Accept in Principle SUBMITTER: Nicholas A. Legatos, American Concrete Inst i tute RECOMMENDATION: Add section:

4-6 Concrete Tanks and Silos. Concrete (including prestressed concrete) tanks containing flammable l iqulds and gases, and concrete si los containing materials susceptible to dust explosions, shall be protected with a l ightning protection system either external to, or embedded in the concrete, in accordance

with Chapter 3. An external protection system, providing a continuous conductor from the tank roof to the ground is preferred. SUBSTANTIATION: To provide l ightning protection for concrete and prestressed concrete tanks containing flammable l iquids such as LNG, LPG, etc. COMMITTEE ACTION: Accept in Principle.

Revise the proposal to read: "Lightning protection systems for concrete (including

prestressed concrete) tanks containing flammable vapors and flammable gases, and concrete si los containing materials susceptable to dust explosions, shall be provided, either external to, or embedded in the concrete, in accordance with Chapter 3 or 6. COMMITTEE ~TATEMENT: The proposal was revised because provisions are already included in Chapter 6 and to provide the options for l ightning protection in Chapter 6.

78- 53 - (Chapter 6 T i t l e ) : Accept SUBMITTER: Technical Committee on Lightning Protection RECOMMENDATION: Change the t i t l e to:

Chapter 6 Protection for Structures containing Flammable Vapors or Flammable Gases. SUBSTANTIATION: To ref lect the new def in i t ion of flammable vapors under 2-2. COMMITTEE ACTION: Accept.

78- 54 - (6-1.1): Accept SUBMITTER: Technical Committee on Lightning Protection RECOMMENDATION: Add "flammable" before "gases" in the f i r s t sentence and change "and" to "or flammable" in the last sentence.

Substitute "Vapors" for " l iqu ids , " delete "such," 6-1.1 would read:

"The chapter applies to the protection of structures containing flammable vapors or flammable gases. For the purpose of this chapter, the term structure shall apply to the vessel, tank, or other container in which flammable vapors or flammable gases are contained." SUBSTANTIATION: To ref lect the new def in i t ion of Flammable Vapors proposed under 2-2. COMMITTEE ACTION: Accept.

78- 55 - (6-1.2): Accept SUBMITTE_RR: Technical Committee on Lightning Protection RECOMMENDATION: I. Change the beginning to read:

6-1.2 Certain types of structures used for the storage of l iquids which can produce flammable vapors or used to store flammable gases are essentially self-protecting . . .

2. Delete "such" from the last sentence. 3. Change "and" to "or" in the second-to-last l ine

of this section. S~BSTANTIATION: I. To ref lect the new def ini t ion of Flammable Vapors proposed under 2-2.

2. "Such" is not needed for c la r i ty . 3. To permit a choice of protection for "other

structures." COMMITTEE ACTION: Accept.

78- 56 - (6-2.1(a)): Accept SUBMITTER: Technical Committee on Lightning Protection RECOMMENDATION: Change to read:

(a) Liquids which can give off flammable vapors shall be stored in essential ly gastight structures. SUBSTANTIATION: To ref lect the new def in i t ion of Flammable Vapors proposed under 2-2. COMMITTEE ACTION: Accept.

78- 57 - (6-3.3.4): Accep t . SUBMITTER: Technical Committee on Lightning Protection RECOMMENDATION: Add "extending at least 2 f t (0.6 m) above the top of the pole, securely attached to the pole (see Figure 6-3.3.4) . . ." after "on a i r terminal."

362

SUBSTANTIATIIO_N: The height of the a i r terminal had not been previously defined. COMMITTEE ACTION: Accept.

78- 58 - (6-4.1): Accept SUBMITTER: Technical Committee on Lightning Protection RECOMMENDATION: Change "Liquids" to "Vapors" in the t i t l e . SUBSTANTIATION: To re f lec t the new def in i t ion of Flammable. Vapors proposed under 2-2. COMMITTEE ACTION:. Accept.

78- 59 - (6-4.1.1): Accept SUBMIT_~ER: Technical Committee on Lightning Protection RECOMMENDATION: Change. the introductory part of the paragraph to read:

6 -4 . l . I Fixed Roof Tanks. Metal l ic tanks with steel roofs of r iveted, bolted, or welded construction, with or without supporting members, used for the storage of l iquids which give o f f flammable vapors at atmospheric pressure . . . . , ~BSTANTIATION: To re f lec t the new de f in i t i on of Flammable Vapors proposed under 2-2. COMMITTEE ACTION: Accept.

78- 60 - (6-4.1.4): Accept SUBMITTER: Technical Committee on Lightning Protection RECOMMENDATION: Revise 6-4.1.4 as follows:

6-4.1.4 Grounding Tanks. Tanks shall be grounded to conduct away the current of d i rect strokes and to avoid the build up and potential which may cause sparks to ground. A metal tank shall be grounded by one of the fol lowing methods: . .

(a) A tank is connected without i'nsulated jo in ts to a grounded metal l ic piping system.

(b) A ver t ica l cy l indr ica l tank rests on earth or concrete and is at least 20 f t (6 m) in diameter, or rests on bituminous pavement and is at least 50 f t (15 m) in diameter.

(c) By bonding the tank to ground through a minimum of two ground terminals as described in 3-13 at maximum lO0 f t (30 m) intervals along the perimeter of the tank. This also applies to tanks with an insulat ing membrane beneath the tank . . SUBSTANTIATION: To correct unclear statements and to define a means of grounding cathodical ly protected tanks. COMMITTEE ACTION: Accept.

7B- 61 - (6-4.2): Accept SUBMI_T!ER: Technical Committee on Lightning Protection RECOMMENDATIp_N: Change heading to:

"Earthen. Containers Enclosing Flammable Vapors at Atmospheric Pressure. " . -

S ta r t paragraph 6-4.2 as fo ' l lows: "Earthen co.ntainers enc los ing flammable v~pors at

atmospheric pressure, l i ned or u n l i n e d . . . ~UBSTANTIATION: To descr ibe the s p e c i f i c c lass o f s t r uc tu re more accu ra te l y . COMMITTEE ACTION: Accept.

78- 62 - ( 6 - 4 . 3 ) : Accept SUBMITTER: Technical Committee on Lightning Protection RECOMMENDATION: Revise 6-4.3 as follows:

6-4.3 Above ground nonmetallic tanks shall be protected as described in 6-3.3,. SUBSTANTIATION: There is no discussion of this topic in Chapter 4. This class of structure can be protected by tile methods described in 6-3.3. COMMITTEE ACTION: Accept.

363

. (Log # 11) 78- 63 - (Chapter 7): Reject SUBMITTER: Roy B. Carpenter, Jr . , Lightning Eliminators & Consultants, Inc. RECOMMENDATION: Add a new chapter 7: ' •

Chapter 7 Lightning ProtectionThrough : Charge Dissipation

7-I Charge Dissipation System (CDS) Operation. A CDS must be composed of three component subsystems

that work in concert to provide l ightning protection through dissipat ing the charge induced on the earth surface by the storm cel ls , rather than by stroke diversion. This is accomplished by col lect ing that charge and channeling i t to an ionizer whichpasses that charge on to the surrounding atmosphere. The subsystems must function as follows:

(a) The Ground Current Collector (GCC) or Charge Collector, col lects the induced charge through the use of a shallow buried conductor surrounding or e l ec t r i ca l l y connected to the s i te or structure to be protected.

(b) The Service Wires (SWi or interconnecting wiring carry the charge between the Charge Collector and the Ionizer. Note: The current is always less than 0.5 amperes.

(c) The Ionizer (or Dissipation Array) is the heart of the system. I t provides the interface between the stored charge and the surrounding atmosphere. The ionizer (DA) design is based on the application of a. well known phenomena: "Point Discharge". That is, a sharp point in the presence of a strong e lect rostat ic f i e l d , wi l l leak of i t s charge by taking an electron from the adjacent a i r molecule.. The storm f i e ld gives that ion mobi l i ty, carrying i t away. The continuing process creates a current flow in sympathy with the wind and e lec t ros ta t ic f i e l d .

7-2 Ionizer Configuration and Material Constraints. The Ionizer (DA) is very sensit ive to size, shape, location, number of points, point shape, point size and point spacing. A compromise in any of these parameters w i l l reduce i t s effectiveness and possible inv i te a stroke.

NOTE: The primary f a i l u re more of the CDS is to function as an a i r terminal, a t t ract ing the stroke.

(a) The DA assembly shall be designed and deployed so that the l ines of equipotential form uniformly, without sharp bends or convergency anywhere on i ts surface.

(b) Under no circumstances shall th is dissipator create or permit to be created, d iscont inui t ies that may form (or permit to be formed) streamers from that ionizer or from within the thus protected f a c i l i t y . I t shall be so designedthat a l l of the dissipator points are at or nearly the same voltage level .

(c) The DA shall be designed to provide no more than 24 points per square foot, evenly spaced and oriented so that a l l are exposed to any e lect rosta t ic f i e ld created by a passing storm. -~

(d) The DA shall be fabricated from a stainless steel wire, whereon are welded the stainless steel. points of not less than I0 cm in length. .

(e). Each DA shall provide not less than, 8OO. points, properly located, sized, shaped and spaced.

( f ) The protected .area for each DA shall be assumed to be a hemispheric volume of height h in radius around i ts loc i ; as i l l us t ra ted in Figure 7-2.1.

(g) The DA assembly shall be mounted in such a way as to assure an unobstructed "view" of the storm e lect rosta t ic f i e ld , from any direct ion. In no case shall i t or any other device on the same structure, be mounted such that the e lec t ros ta t ic f i e l d is l imited, shadowed, or obscured from the ion izer /d iss ipator ; point face. ,

(h) All metal l ic components of the DA shall be of stainless steel or of a comptabile metal ".

( i ) The DA assembly shall be elevated to a height of no less than lO meters above i ts surroundings.~

( j ) Where more than one DA assembly is used in a given area, they may be separated by a distance equal to the combination of the two heights; provided each one sa t is f ies the foregoing c r i t e r i a .

7-3 The Ground Current Collector (GCCi Configuration and Material. The GCC assembly shall be designed, developed and deployed so as to provide the f i r s t conductor, the moving surface charge wi l l meet as the storm approaches the s i te . I t must col lect that

surface charge and conduct i t to closest service wires, with minimum circuit impedance.

(a) The GCC shall provide an electrical interface with al l grounded components within the protected area.

(b) The GCC shall be composed of a combination of Ground Rods and conductors of compatible metals; sized and deployed so as to minimize the surge impedance from one point in the system to any other point in the system.

(c) The ground rods needs not exceed 1.5 Meters (6 ft) in length and may be of the conventional copper clad steel. However, the chemically charged electrodes are preferred because of the lower surge impedance and DC interface resistance.

(d) The related circumferential ground wires may be of the conventional stranded type; however, where the GCC is the only design objective, copper tubing is preferred. Where copper tubing is used i t shall be of I/4 or 3/8 inch diameter, soft drawn 99 percent pure.

(e) The GCC shall be buried at a depth of no less than 10 cm or more than 50 cm.

(f) Where soil conditions are unfavorable for copper, other metals may be used; however, stainless steel is preferred. Since the current flow is low (100 microamperes to 0.5 amperes). The wire or tube size should be selected on the basis of area in contact with soil; rather than current carrying capacity.

7-4 Interconnecting Service Wire (ISW). The ISW must provide adequate redundant paths for the dissipation current, from the collection points (GCC) to the DA assembly, by the shortest, low impedance path that is practical.

(a) The ISW wire size is selected on the basis of mechanical strength, rather than current carrying capacity. However, i ts surge impedance is also a driving factor. A I/0 AWG is considered the smallest practical size; a minimum of I/4 inch diameter tubing is recommended.

(b) The material to be used is to be determined based on the application. Normally copper is recommended, however, stainless steel is also satisfactory. Others must be evaluated against the preceding cr i ter ia.

7-5 Application to Buildings. Since buildings vary in character signif icantly, so must the DA configurations and development concepts. The preceding DA deployment cr i ter ia must be carefully applied to assure satisfactory performance. The subsequent options presented hearafter are representative of the potential DA configurations. Others are possible.

7-5.1 Roofs with Various Forms of Pitch. Figure 7-5.1 and 7-5.2 i l lustrates some potential deployment concepts for the various roof types. In implementing any of these concepts, the Ionizer design parameters and constraints of paragraph 7-2 shall be adhered to without compromise. They need not be changed as the result of building configuration anomalies. Only the DA deployment (location and mounting concept) may vary.

(a) Steep Sloped Roofs. (Those of I/2 to ful l pitch as i l lustrated by Figure 7-5.1). The dissipative media shall be deployed along both sides of the roof ridge, as i l lustrated. The number of rows and length shall be determined by the roof length; but, in no case shall there be less than 800 f t of I0 by IO Dissipation Wire used

NOTE: 10 x 10 Dissipation Wire is stainless steel wire where the points are 10 cm high and spaced by IO cm.

(b) Shallow Sloped Roofs. (Those slopes of less than I/2) as i l lustrated by Figure 7-5.2. The dissipative media shall be uniformly distributed between both sides of the peak and around the outer edge of the roof line. There shall be at least one run on each side of the ridge and completely around the outer edge. In no case shall there be less than 800 f t of the lO by lO Dissipation Wire used; nor shall there be less than two strands of Dissipation Wire used in any single run.

(c) The Interconnecting Service Wires (ISW). The ISW shall be as defined in paragraph 7-4. They may be internal or external. The ISW's may be deployed via a route having the least impact on esthetics. The length should be kept as short as practical. There shall be at least four connections per building or one for every 100 f t of perimeter, whichever is greater.

7-5.2 Flat Roofs, Single and Multilevel. Figures 7-5.3 and 7-5.4 i l lustrate some of the DA installation concepts for f la t roofs. In al l cases, the deployment cr i ter ia shall be as defined under paragraph 7-2.

(a) Flat Roofs with Parapets. These shall be protected as i l lustrated by Figure 7-5.3. The mounting bracket shall be mounted as close to the edge as possible and provide a slope of not less than 30 degrees from the horizontal for the wire mounting plane. One row of dissipation medium shall be used on each roof level. No less than 800 f t of Dissipation Wire shall be used and/or no less than two strands of Dissipation Wire shall be used on each level, or for any separate run.

(b) Flat Roofs without Parapets. These shall be protected as i l lustrated by Figure 7-5.4. The deployment cr i ter ia shall be as defined by paragraph a) above; except that the Dissipation Wire mounting brackets for the interior areas shall be of the same height for al l strands of wire; except where penthouses are involved. Any penthouse shall be treated as a parapet (7-5.2a).

(c) The Interconnecting Service Wires (ISW). The ISW shall be as defined in paragraph 7-4. They may be internal or external. The ISW's may be deployed via a route having the least impact on esthetics. The length should be kept as short as practical. There shall be at least four connections per building or one for every log f t of perimeter, whichever is greater.

7-5.3 Applications to Towers, Poles and Like Structures.

(a) General. Towers require special consideration. The requirements vary somewhat as a function of height. All requirements of Paragraphs 7-2, 7-3 and 7-4 shall apply, within the constraints herein defined.

(b) Those of less than 80 meters height. These shall be protected through use of a hemispherically shaped DA, similar to that i l lustrated by Figure 7-5.5. The diameter of the DA shall not be less than 5 meters.

(c) Those in excess of 80 meters in height. These shall be protected through use of a trapezoidal shaped DA, similar to that i l lustrated by Figure 7-5.6. The length of the trapezoid, as measured from the top to the apex of the catanary, shall be no less than 15 meters, plus .02 times the tower height in excess of 100 meters.

7-5.4 Appliction to Heavy-Duty Stacks (Excluding Cooling Towers).

(a) General. Towers require special consideration. The requirements vary somewhat as a function of height. All requirements of Sections 7-2, 7-3 and 7-4 shall apply, within the constraints herein defined.

(b) Construction. The DA shall be a hemispherical shaped device, similar to that i l lustrated by Figure 7-5.7. The inner diameter (ID) shall be selected so as to permit resting the DA on the stack rim without interfering with stack operation. The outer diameter shall be at least 2.4 meters greater than the ID.

(c) Materials. The materials for the DA frame shall be unaffected by the flue gasses or related by-products.

7-5.5 Application to Flammable Storage Facil i t ies. (a) General. Towers require special consideration.

Tile requirements vary somewhat as a function of height. All requirements of Sections 7-2, 7-3 and 7-4 shall apply within the constraints herein defined.

(b) For Cone Roof Tanks. These tanks shall be protected through use of a conic shaped DA as i l lustrated by Figure 7-5.8, or similar shaped device. There shall be no less than one radial every 30 degrees; and no less than 300 meters of 10 by 10 Dissipation Wire used per tank, whichever is the greater.

(c) For Floating Roof Tanks (Open). These tanks shall be protected through use of a perimeter dissipator assembly, similar to that i l lustrated by Figure 7-5.9. Each mounting bracket shall be of hot dipped, galvanized iron, with provisions for at least three strands of Dissipation Wire, separated by not less than 15 cm separation; or at least 350 meters of Dissipation Wire; whichever is greater.

(d) For Spherical Tanks. These tanks shall be protected through use of a hemispherical shaped dissipator, mounted on a pole or tower section to raise i t at least 3 meters above the tank top, similar to

364

that i l lustrated by Figure 7-5.10. The hemisphere diameter shall be no less than 4 meters or 70 percent of the tank diameter,.whichever is greater.

(e) Materials. The materials used shall be compatible with the tanks being protected. That is, no significant galvanic potential difference.

(f) Connections. All connections for flammables protection shall be made directly to the metallic container. Care shall be taken to be sure that paint or corrosion does not effectively insulate the connection from the container.

7-5.6 Applications to Parked Aircraft. (a) General. Parked aircraft on an open ramp,

particularly when undergoing fuel transfer, are vulnerable to lightning and static discharge. The CDS wil l eliminate that risk, i f and only i f the DA and grounding pins are properly integrated with i t .

(b) Protection Installation. The DA shall be of a hemispheric shape, similar to that i11ustrated by Figure 7-5.11, elevated on a pole to a height of not less than the highest point of the aircraft to be protected. The diameter of the DA shall be not less than 2.5 meters or 20 percent of the aircraft length, whichever is greater.

(c) Connections. The DA shall be directly tied to al l of the position grounding pins via the shortest route, with a copper wire of not less than 0.75 cm diameter. All connectins shall be brazed.

7-5.7 Application to Airport Control Towers. (a) General. Lightning strikes to these towers

cause failure in the communications sytems and loss of airport control. Storms in the area also create a high noise level within the communications systems, due to corona discharge from colocated devices. The DA, when properly installed, wi l l not eliminate the stroke potential and improve the noise figure of the receivers.

(b) Protection Installation. A hemispherically shaped DA similar to that i l lustrated by Figure 7-5.12 shall be installed on the control tower and elevated above all colocated devices. No antenna of any significance shall extend above i t . The hemispheric DA shall be no less than 5 meters in diameter, with lO by 10 Dissipation Wire covering at least 90 percent of i ts hemispherical surface, with spacing no less than 10 centimeters, or more than 15 centimeters. The hemisphere DA shall be elevated to a height of not less than 3 meters above the tower roof.

(c) Connections. Since the DA is to protect the tower only; the DA shall be solidly connected into building steel through redundant paths.

Figure 7-5.1 Protection Deployment Steep Pitched Roofs

Figure 7-5.2 Protection Deployment Shallow Pitched Roofs

Figure 7-2.1 Protected Area Projection.

Figure 7-5.3 Protection for Flat Roof Buildings with Parapets

365

Figure 7-5.4 Protection for Flat Roof Buildings significantly with t h e :tack Without Parapets size add t ype .

I Figure 7-5.7 A Typical Stack Array Installation.

Stainless Steel Dissipation Ware

J / -

uminum P o l e

Figure 7-5.5 Typical Hemispheric Configuration ~---~

Figure 7-5.8 A Typical Conic Array Installation for Cone Roof Storage Tanks

Figure 7-5.6 Typical Trapezoid Configuration.

366

. . . . . . . =, "::='.

~ -L___Z \ . ~<.~

J

k ' , • A

Figure 7-5.9 Typical Perimeter Array, Floating Roof Tank.

H ~ 11 Figure 7-5.1] Protection for Aircraft on Open Ramps

x \ \

i

I I • , j "

;~:. 7

\i i " • : ,~

/ " '

! . ^ ~ . .

i

Figure 7-5.10 Protection for Spherical Storage Tanks

/ I

Figure 7-5.1Z Protection for AircraFt Control Towers

367

SUBSTANTIATION: The referenced NFPA Code makes no mention of the lightning protection system known as: "The Dissipation Array System", yet i t has been in use since 1971; and has proven through statist ics (over 4000 system-years), that the system when properly implemented, wi l l prevent lightning striks to the thus protected area.

Further, the present make up of the "Technical Committee on Lightning Protection" contains many members who are opposed to the DAS, because of i ts potential impact on their business or reputation.

NOTE: Supporting material is available for review at NFPA Headquarters.

COMMITTEE ACTION: ReJect. ~OMMITTEE STATEMENT: The Committee feels there is a lack of adequate documentation, technical and scientif ic data submitted. There is a need for an unbiased third party evaluation which supplies technical and scienti f ic data. Without this unbiased data, i t is not prudent for the Committee to act affirmatively. As proposed, the wording provides design guidance and is not enforceable as a Code. Although not part of the reason for rejection, the Committee takes exception to the second paragraph of the substantiation of the proposal which reflects upon the professional impartiality of the Committee.

78- 64 - (Chapter 7): Accept SUBMITTER: Technical Committee on Lightning Protection ~OMMENDATION: Add new Chapter 7, Protection of Structures Housing Explosives and Energetic Materials:

Chapter 7 Protection of Structures Housing Explosives and Energetic Materials

7-I* General. This chapter provides the minimum technical requirements for lightning protection of structures housing explosive and energetic materials. This Chapter does not address the design of storage containers or processing equipment that may be contained in these structures. All requirements of Chapter 3 shall apply except as modified herein.

7-2 Design Considerations. Lightning protection systems designed to protect structures housing explosives and energetic materials shall be based on a striking distance of lO0 feet as discussed in 6-3.3.

NOTE: When the effects of electromagnetic coupling is of concern a mast of overhead wire (catenary) systems may be preferred over integral systems unless a Faraday cage or shield is required. The removal (isolation) of the down conductors wi l l reduce the magnetic f ield strength in the structure and reduce the probability of a sideflash from a down conductor.

7-3 Types of Systems. 7-3.l Mast-type Systems. Mast-type systems shall be

designed as specified in 6-3.3.2. 7-3.2 Overhead Wire (Catenary) Systems. Catenary

systems shall be designed as specified in 6-3.3.2. 7-3.3 Integral systems. An integral lightning

protection system is a system which ut i l izes air terminals mounted directly on the structure to be protected. These type air termination systems are as described in Chapter 3. Air terminal spacing shall be modified as necessary to provide a zone-of-protection defined by a IO0-foot striking distance.

When an integral lightning protection system is used to protect the structures covered by this chapter, i t is cr i t ical that the bonding requirements of Chapter 3 be met. I t is also cr i t ica l that a rigorous maintenance schedule be maintained for this type of system.

7-3.4 Faraday Cage. The optimum scheme for protecting extremely sensitive operations from all forms of electromagnetic radiation is to enclose the operation(s) or fac i l i t y inside a Faraday cage. A true Faraday cage is d i f f i cu l t to construct and economically just i f ied only for cr i t ical fac i l i t ies or where extremely sensitive operations warrant this level of protection.

Effective lightning protection is similarly provided by metallic structures such as those formed by the steel arch or the reinforcing steel in the walls and floors of earth-covered magazines i f the steel reinforcement is bonded together and i t meets the minimum ground system resistance requirements of 7-4.

7-4 Grounding. 7-4.l General. A ground loop conductor is required

for al l lightning protection systems used to protect the subject structures. All down conductors structural steel, ground rods, and other grounding systems shall be connected to the ground loop conductor.

Exception: For structures with areas of 500 square feet or less or those that can be protected by a single mast or air terminal, the ground loop conductors shall not be required.

7-4.2 Metal Portable Magazines. Portable magazines that meet the requirements of a Faraday cage as described in 7-3.4 shall be grounded using a minimum of 2 ground terminations located at opposite corners within I foot of ground level for large portable magazines. Additional ground rods shall be added so the spacing shall not exceed 60 feet on average. Primary size conductors shall be used to interconnect the portable magazine to the ground rods.

7-5 Bonding. 7-5.1 General. I t is cr i t ical that the bonding

requirements of Chapter 3 be enforced for the protection of structures housing explosives or other energetic materials. The material used to bond items to the grounding loop conductor shall meet the requirements of 3-2. Section 3-2 provides the requirements for the use of dissimilar metals.

7-5.2 Bonding Resistance. The resistance of any object bonded to the lightning protection system shall not exceed one ohm. For static dissipative systems such as conductive floors, workbenches, etc. bond resistance of 1 megohm shall be acceptable.

7-5.3 Painting. Wires and conductors bonded to the lightning protectin system shall not be painted.

7-5.4 Magazines. 7-5.4.1 Earth Covered Magazines. Metal ventilators,

steel doors, door frames, and steel reinforcement shall be bonded to the structure's grounding system. Incoming power, data, and communication cables shall be bonded to the secondary girdle or steel reinforcement as i t enters the structure.

7-5.4.2 Metal Portable Magazines. Portable box-type magazines made of 3/16 in. steel or equivalent where the walls, floor, and roof are welded together shall require bonding of the doors across the hinges. Bonding of services, data lines, and communication lines shall also be provided.

7-5.5 Fences. Fences shall have bonding across gates as well as other discontinuities and shall be bonded to the lightning protection system ground loop conductor i f they cross or come within the sideflash distance of the structure of lightning protection system. Bonding across discontinuities in metallic fences shall be provided as necessary to provide electrical continuity.

7-5.6 Railroad Tracks. All railroad tracks that cross a lightning protection system ground ring shall be bonded to that ground ring as discussed in ?-5.6. I f the tracks are used to carry electrical signals, they shall have insulated joints immediately external to the bond to the lightning protection ground ring. I f these tracks enter a fac i l i t y , they shall also be bonded to the frame of the structure (or equivalent).

7-6 Surge Protection. Surge protection is required for al l power, communication, or data conductors entering or exiting a structure housing explosives. This may include transient voltage suppression, fiber optic data lines, or isolation transformers.

7-7* Maintenance and Inspection. The effectiveness of a lightning protection system is best ensured by a quality control program designed to ensure that the system is not degraded by age, mechanical damage, or by modifications to the structure. A maintenance and inspection plan shall be developed for al l protection systems used to protect structures housing explosives.

The in i t ia l instal lation shall be inspected by the authority having jurisdiction (or their designated representative). I t shall be recertified after any work is done on the structure.

A-7-1 Due to the possibi l i ty of danger to the surrounding area, an increased level of protection efficiency as defined herein is necessary for such structures. The decision of when to protect these structures should be le f t to the authority having jurisdict ion.

368

The protection of the contents contained in structures housing explosives must take into account the packages used to contain these materials as well as bonding or grounding requirements specified by the authority having jur isd ic t ion.

The protection of the contents contained in structures housing explosives must take into account the packages used to contain these materials as well as bonding or grounding requirements specified by the authority having jur isd ic t ion.

A-7-7 Maintenance and Inspection. A-7-7.1 General. To ensure that the protection

system used to protect structures housing explosives is properly maintained, i t is necessary that i t be inspected visual ly twice a year and e lec t r ica l ly approximately once a year. To ensure the systems are tested during al l four seasons over a six year period, 7 month and 14 month test cycles are suggested.

A-7-7.2 Visual (7 Month) Test. The l ightning protection system shall be v isual ly inspected every 7 months for evidence of corrosion or broken wires/connections. All necessary repairs shall be made immediately. Any detected damage to the system shall be entered in the test records as required in 7-8.5.

A-7-7.3 Electrical (14 month) test. The l ightning protection system shall be tested e lec t r i ca l l y every 14 months. The test shall be conducted in accordance with the appropriate test equipment manufacturer's instructions by personnel famil iar with l ightning protection system testing.

A-7-7.4 Test. Equipment. Only those instruments designed speci f ical ly for earth ground systems testing are acceptable for use in ground resistance testing. The instrument must be capable of measuring 10 ohms +/- 10 percent.

The instrument used to measure bonding resistance must be capable of measuring I OHM• +/-10 percent. SUBSTANTIATION: There is no technical reason to exclude the protection of structures housing explosives and energetic materials from this Code. There are other documents that refer to NFPA 78 for this protection, therefore this section was added to f i l l this need. COMMITTEE ACTION: Accept.

(Log # 43) 78- 65 - (Appendix A): Reject SUBMITTER: Robert D. Harger, Harger Lightning Protection, Inc. RECOMMENDATION: Delete Figures A-2-2(a); A-2-2(b); A-2-Z(c); A-2-2(d); A-2-2(e); A-2-2(f); and A-2-2(g) in their ent irety. This wi l l also include the "*" references in Chapter 3. SUBSTANTIATION: There are none of the figures that seem to offer any help to the user of this code. There is no reason to label a point or a base as in A-2-2(a). Not a l l a i r terminals require bases or for that matter a point. The A-2-2(b) "bonding" figure is extremely poor. The sketches of the main and secondary conductor are very poor and even i f of good quali ty would do l i t t l e to describe a l ightning conductor. Figure A-2-2(d) is contradictive to the def in i t ion i t is supposed to c la r i fy . Figure A-2-2(e) likewise does not offer the user any assistance. I f he is unable to understand the height of a structure, he wi l l not be able to apply the requirements of the code. Also there is no Class I I modified. Figure A-2-2(f) is extremely simple in nature and further, recent evidence indicates ground plates may be of l i t t l e or no value. COMMITTEE ACTION: Reject. COMMITTEE STATEMENT: The figures are informational and do offer some useful value to the user.

78- 66 - (A- I - I .2) : Accept SUBMITTER: Technical Committee on Lightning Protection

I RECOMMENDATION: Delete second paragraph. SUBSTANTIATION: This section no longer discusses l ightning protection for structures housing explosives. COMMITTEE ACTION: Accept.

78- 67 - (A-6-1.l): Accept SUBMITTER: Technical Committee on Lightning Protection RECOMMENDATION: Add new paragraph A-6.1.1:

A-6-1.l Flammable vapors can eminate from a flammable ' l iquid (flash point below 100°F (37.8°C)) or a combustible l iquid (flash point at or above 100°F (37.8°C)) when the temperature of the l iquid is at or above i ts flash point. This chapter applies to these l iquids when stored at atmospheric pressure. Flammable gases can also eminate from these l iquids when stored at atmospheric pressure.

Metall ic tanks, vessels, and process equipment that contain flammable or combustible l iquids under pressure or flammable gases under pressure normally do not require l ightning protection, since this equipment is well shielded from l ightning strikes. Equipment of this type is normally well grounded'and is thick enough not to be punctured by a direct str ike.

This chapter applies to flammable or combustible l iquids such as gasoline, diesel, j e t fuel, fuel o i l , or crude oi l stored at atmospheric pressure. I t does not apply to l iquids or gases stored under pressure such as l iqu i f ied natural gases or l i qu i f ied petroleum gases.

Add asterisk to 6-1.I. SUBSTANTIATION: There has been confusion over application of this chapter. This appendix section gives explanatory information. COMMITTEE ACTION: Accept.

78- 68 - (Appendix B): Accept SUBMITTER: Technical Committee on Lightning Protection RECOMMENDATION: Include the following material concerning inspection and maintenance of l ightning protection systems in the appendix.as Appendix B.

This requires the changing of the present "B!' to "L" and present "L" to "M".

Appendix B Inspection and Maintenance of Lightning Protection Systems

B-I Inspection of Lightning Protection Systems. B- l . l Frequency of Inspections. I t is understood

that al l new. l ightning protection systems must be inspected following completion of their insta l la t ion. However, i t is very important to make periodic inspections of exist ing systems. The interval between inspection should be determined by such factors as:

(a) Classif ication of structure or area protected. (b) Level of protection afforded by the system. (c) Immediate environment (Corrosive atmospheres). (d) Materials from which components are made. (e) The type of surface to which the l ightning

protection components are attached. B - l - l . l In addition to the above, a l ightning

protection system should be inspected whenever any alterations or repairs are made to a protected structure; also, following any known l ightning discharge to the system.

B-1-I.2 I t is recommended l ighnting protection systems be visual ly inspected at least annually. In some areas where severe climatic changes occur i t may be adviseable to visual ly inspect systems semi-annually or following extreme changes in ambient temperatures. Complete, in-depth, inspections of a l l systems should be completed every three to f ive years. I t is recommended that c r i t i ca l systems be so inspected every one to three years depending on occupancy or the environment in which the protected structure is located.

B- l - l .3 In most geographical areas, and especially in areas which experience extreme seasonal changes in temperature and ra in fa l l , i t is adviseable to stagger inspections so that, earth resistance measurements, for example, are made in the hot dry months as well as the cool wet months. Such s~aggering of inspections and testing is important in order to assess the effectiveness of the l ightning protection system during the various seasons throughout the year.

B-1.2 Visual Inspection: Visual inspections are made to ascertain the following:

(a) The system is in good repair. (b) There are no loose connections which might

result in high resistance jo in ts . (c) No part of the system has been weakened by

corrosion or vibrat ion.

369

(d) All down conductors and ground terminals are intact. Non severed.

(e) All conductors and system components are securely fastened to their mounting surfaces and are protected against accidental mechanical displacement as required.

(f) There have not been additions or alterations to the protected structure which would require additional protection.

(g) There has been no visual indication of damage to surge suppression (over voltage) devices.

(h) The system complies in al l respects with the current edition of the Lightning Protection Code.

B-I.3 Complete Testing and Inspection. Such testing and inspection includes the visual inspections described above in addition to the following:

(a) Perform tests to verify continuity of those parts of the system which were concealed (bui l t - in) during the in i t ia l instal lation and which are not now available for visual inspection.

(b) Conduct ground resistance tests of the ground termination system and its individual ground electrodes i f adequate disconnecting means have been provided. These test results should be compard with previous, or original, results and/or current accepted values for the soil conditins involved. I f i t is found the test values dif fer substantially from previous values, obtained under the same test procedures, additional investigations must be made to determine the reason for the difference.

(c) Perform continuity tests to determine i f suitable equipotential bonding has been established for any new services or constructions which have been added to the interior of the structure since the last inspection.

B-I.4 Inspection Guides and Records. Inspection guides or forms should be prepared and made available to the authority responsible for conducting inspections of lightning protection systems. These guids should contain sufficient information to guide the inspector through the inspection process so that he may document al l areas of importance relating to the methods of installation, the type and condition of system components, test methods and the proper recording of the test data obtained.

B-I.5 Records and Test Data. The inspector or inspection authority should compile and maintain records pertainin 9 to the following:

(a) The general condition of air terminals, conductors, and other components.

(b) The general condition of corrosion protection measures.

(c) The security of attachment of conductors and components.

(d) Resistance measurements of various parts of the ground terminal system.

(e) Any variations from the requirements contained in this lightning protection code.

B-2 Maintenance of Lightning Protection Systems. B-2.1 General. Maintenance of a lightning

protection system is extremel'y important even though the lightning protection design engineer has taken

special precautions to provide corrosion protect ion and has sized the components according to t h e i r pa r t i cu la r exposure to l i gh tn ing damage. Many system components tend to lose t h e i r ef fect iveness over the years because of corrosion factors , weather re lated damage, and stroke damage. The physical as well as the e lec t r i ca l charac ter is t i cs of the l i gh tn ing protect ion system must be maintained in order to maintain compliance with design requirements.

B-2.2 Maintenance Procedures. B-2.2.1 Periodic maintenance programs should be

establ ished for a l l l i gh tn ing protect ion systems. The frequency of maintenance procedures is dependent on the fo l lowing:

(a) Weather re lated degradation. (b) Frequency of stroke damage. (c) Protection level required. (d) Exposure to stroke damage. B-2.2.2 Lightning protection system maintenance

procedures should be established for each system and should become a part of overall maintenance program for the structure which i t protects.

A maintenance program should contain a l i s t of more or less routine items that may" serve as a check l i s t so that a definite maintenance procedure can be followed regularly. I t is the repeatability of the procedures that enhance the effectiveness of a good maintenance program.

A good maintenance'program should contain provisions for the following:

(a) Inspection of al l conductors and system components.

(b) Tightening of al l clamps and splicers. (c) Measurement of lightning protection system

resistance. (d) Measurement of resistance of ground terminals. (e) Inspection of and/or testing of surge protection

devices to determine their effectiveness compared with similar new devices.

(f) Re-fastenlng and tightening of components and conductors as required.

(g) Inspection and testing as required to determine i f the effectiveness of the lightning protection system has been altered due to additions to, or changes in, the structure.

B-2-3 Maintenance Records. Complete records shall be kept of al l maintenance procedures and routines and shall include corrective actions taken or to be taken. Such records provide a means of evaluating syste m components and their installation. They also serve as a basis for reviewing maintenance procedures as well as updating preventative maintenance programs. JUBSTANTIATIO__N: Material is important to the proper functioning of a lightning protection system and its inclusion in the appendix makes i t readily available to users. COMMITTEE ACTION: Accept.

370