APSC FILED Time: 6/10/2015 9:14:01 AM: Recvd 6/10/2015 9:10:59 AM: Docket 14-069-C-Doc 109 EXHIBIT 19 DOCKET 14-069-C IEEE Guide for the Protection of IEEE Std 90003™-2008 Installations from Communication IEEE Std 90003™-2008 Lightning Effects IEEE Power Engineering Society Sponsored by the Power Systems Communications Committee IEEE Park Avenue New York, NY 10016-5997 USA 15 August 2011 IEEE Std 1692™-2011 APSC FILED Time: 6/10/2015 9:14:01 AM: Recvd 6/10/2015 9:10:59 AM: Docket 14-069-C-Doc 109 TM 109 APSC FILED Time: 6/10/2015 9:14:01 AM: Recvd 6/10/2015 9:10:59 AM: Docket 14-069-C-Doc IEEE Std 1692 -2011 IEEE Guide for the Protection of Communication Installations from Lightning Effects Sponsor Power Systems Communications Committee of the IEEE Power Engineering Society Approved 16 June 2011 IEEE-SA Standards Board APSC FILED Time: 6/10/2015 9:14:01 AM: Recvd 6/10/2015 9:10:59 AM: Docket 14-069-C-Doc 109 Abstract: The document addresses methods and practices necessary to reduce the risk of damages to communications equipment within structures arising from lightning surges causing GPR (ground potential rise) and similar potential differences Keywords: IEEE 1692, lightning, protection, communications equipment, towers Acknowledgments: Figures 1, 2, and reprinted with permission from Expert Systems Programs and Consulting, Inc., GPR-Expert—Ground Potential Rise Protection using a High Voltage Interface June 15, 1998 Original graphics of Figures 1, 2, and copyrighted © by John S Duckworth, P.E., CEO, Expert Systems Programs and Consulting, Inc • The Institute of Electrical and Electronics Engineers, Inc Park Avenue, New York, NY 10016-5997, USA Copyright © 2011 by the Institute of Electrical and Electronics Engineers, Inc All rights reserved Published 15 August 2011 Printed in the United States of America IEEE is a registered trademark in the U.S Patent & Trademark Office, owned by the Institute of Electrical and Electronics Engineers, Incorporated National Electrical Code, NEC, and NFPA 70 are registered trademarks in the U.S Patent & Trademark Office, owned by the National Fire Protection Association, Inc PDF: Print: ISBN 978-0-7381-6671-1 ISBN 978-0-7381-6672-8 STD97120 STDPD97120 IEEE prohibits discrimination, harassment and bullying For more information, visit http://www.ieee.org/web/aboutus/whatis/policies/p9-26.html No part of this publication may be reproduced in any form, in an electronic retrieval system or otherwise, without the prior written permission of the publisher APSC FILED Time: 6/10/2015 9:14:01 AM: Recvd 6/10/2015 9:10:59 AM: Docket 14-069-C-Doc 109 IEEE Standards documents are developed within the IEEE Societies and the Standards Coordinating Committees of the IEEE Standards Association (IEEE-SA) Standards Board The IEEE develops its standards through a consensus development process, approved by the American National Standards Institute, which brings together volunteers representing varied viewpoints and interests to 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9:14:01 AM: Recvd 6/10/2015 9:10:59 AM: Docket 14-069-C-Doc 109 Introduction This introduction is not part of IEEE Std 1692-2011, IEEE Guide for the Protection of Communication Installations from Lightning Effects The document addresses methods and practices necessary to reduce the risk of damages to communications equipment within structures arising from lightning surges causing GPR (ground potential rise) and similar potential differences According to the National Lightning Safety Institute accurate information about lightning-caused damage is elusive (see National Lightning Safety Institute [B31]).a The U.S Insurance Institute estimates the annual damages from lightning in the United States to be $5 billion with the lightning strike claims, not including U.S government property losses, paid per year being $820 million (see Brashear [B6]) Other sources provide much higher values Lightning damage to equipment results in losses exceeding $26 billion annually in North America, and nearly three times that worldwide with more than 150 strikes per second (see Duckworth [B9]) Insurance payout resulting from lightning damage, accounts for approximately 7.5% of all U.S insurance company distributions (see Brashear [B6]) Ironically, lightning damage to equipment could be all but totally prevented Special protection methods to minimize lightning damage are simple, very reliable, and inexpensive, particularly when compared to the cost of equipment repair and replacement, as well as the possible consequences of harm to personnel However, methods for lightning special protection cannot be found in the code books, e.g., National Electrical Code® (NEC®) or the National Electrical Safety Code® (NESC®).b Per the scopes of these two well-known codes, lightning protection is not covered, yet they are relied upon for practically all general construction in the United States The Lightning Protection Standard® (NFPA 780®) should not be expected to provide guidance for the prevention of lightning damage to equipment The scope of NFPA 780 covers the protection of structures only NFPA 780 (4.18.3.2) does contain requirements for the surge protection of all service entrance signal, data, and communication circuits as well as surge protection for all service entrance power circuits Common grounding requirement (4.14) for electric service, communications, and antenna system grounds as well as underground metallic piping systems is also included in NFPA 780 Documented methods for the special protection of equipment from lightning cannot be found in the two main codes, NEC or NESC, or the Lightning Protection Standard that are systematically referred to for practically all general construction in the United States This is in part the reason why there is so much needless lightning damage This guide is dedicated to providing special lightning protection methods for equipment and filling the vacuum that currently exists today (see Duckworth [B9]) Protection of the structure from lightning plays an important role in the protection of the equipment within the structure While the protection of the equipment is the main objective of this document, the protection of the structure housing the equipment is also covered in this document The equipment housed in the structure is often worth many times the value of the structure This standard was prepared by the Wire-Line Subcommittee of the IEEE Power Systems Communications Committee of the IEEE Power Engineering Society a The numbers in brackets correspond to those of the bibliography in Annex A National Electrical Code, NEC, and NFPA 70 are registered trademarks in the U.S Patent & Trademark Office, owned by the National Fire Protection Association b iv Copyright © 2011 IEEE All rights reserved APSC FILED Time: 6/10/2015 9:14:01 AM: Recvd 6/10/2015 9:10:59 AM: Docket 14-069-C-Doc 109 Notice to users Laws and regulations Users of these documents should consult all applicable laws and regulations 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accessed at the following URL: http://standards.ieee.org/reading/ieee/interp/ index.html v Copyright © 2011 IEEE All rights reserved APSC FILED Time: 6/10/2015 9:14:01 AM: Recvd 6/10/2015 9:10:59 AM: Docket 14-069-C-Doc 109 Patents Attention is called to the possibility that implementation of this recommended practice may require use of subject matter covered by patent rights By publication of this recommended practice, no position is taken with respect to the existence or validity of any patent rights in connection therewith The IEEE is not responsible for identifying Essential Patent Claims for which a license may be required, for conducting inquiries into the legal validity or scope of Patents Claims or determining whether any licensing terms or conditions provided in connection with submission of a Letter of Assurance, if any, or in any licensing agreements are reasonable or non-discriminatory Users of this recommended practice are expressly advised that determination of the validity of any patent rights, and the risk of infringement of such rights, is entirely their own responsibility Further information may be obtained from the IEEE Standards Association Participants At the time this recommended practice was submitted to the IEEE-SA Standards Board for approval, the PSCC Wire-Line Subcommittee (SC-6) had the following membership: Percy E Pool, Co-Chair and Technical Editor Larry S Young, Co-Chair and Secretary Ron Baysden Steve Blume Joe Boyles Claude Brisson Timothy Conser Jean DeSeve Ernest M Duckworth, Jr John Fuller Ernie Gallo Gaetano Grano David P Hartmann Dan Jendek Richard L Knight Randall Mears Mark Simon John Wruble The following members of the individual balloting committee voted on this recommended practice Balloters may have voted for approval, disapproval, or abstention William J Ackerman S Aggarwal John Banting R Baysden Joe Boyles Chris Brooks Gustavo Brunello William Byrd Suresh Channarasappa Timothy Conser Michael Dood Ernest Duckworth Donald Dunn Gary Engmann Gaetano Grano Randall Groves Edward Hare John Hawkins Lee Herron Gary Hoffman Ronald W Hotchkiss Piotr Karocki Yuri Khersonsky Stanley Klein Richard Knight Joseph Koepfinger Robert Konnik Jim Kulchisky David Landry Greg Luri Michael Maytum William McCoy Daniel McMenamin Joseph Mears Jerry Murphy Arthur Neubauer Michael S Newman Gary Nissen Chris Osterloh Lorraine Padden vi Copyright © 2011 IEEE All rights reserved Donald Parker Percy Pool R Ray Charles Rogers Bartien Sayogo Gil Shultz Mark Simon James Smith Jeremy Smith Jerry Smith Gary Stoedter David Tepen James Tomaseski Eric Udren John Vergis Karl Weber James Wilson Jan Wisniewski John Wruble Larry Young APSC FILED Time: 6/10/2015 9:14:01 AM: Recvd 6/10/2015 9:10:59 AM: Docket 14-069-C-Doc 109 When the IEEE-SA Standards Board approved this standard on 16 June 2011, it had the following membership: Richard H Hulett, Chair John Kulick, Vice Chair Robert M Grow, Past Chair Judith Gorman, Secretary Masayuki Ariyoshi William Bartley Ted Burse Clint Chaplin Wael Diab Jean-Philippe Faure Alexander Gelman Paul Houzé Jim Hughes Joseph L Koepfinger* David J Law Thomas Lee Hung Ling Oleg Logvinov Ted Olsen Gary Robinson Jon Walter Rosdahl Sam Sciacca Mike Seavey Curtis Siller Phil Winston Howard L Wolfman Don Wright *Member Emeritus Also included are the following nonvoting IEEE-SA Standards Board liaisons: Satish K Aggarwal, NRC Representative Richard DeBlasio, DOE Representative Michael Janezic, NIST Representative Don Messina IEEE Standards Program Manager, Document Development Erin Spiewak IEEE Standards Program Manager, Technical Program Development vii Copyright © 2011 IEEE All rights reserved APSC FILED Time: 6/10/2015 9:14:01 AM: Recvd 6/10/2015 9:10:59 AM: Docket 14-069-C-Doc 109 Contents Overview 1.1 Scope 1.2 Purpose 1.3 Application Normative references Definitions acronyms, and abbreviations 3.1 Definitions 3.2 Acronyms and abbreviations Overview and background Lightning effects 5.1 Surge protective devices (SPD) and wire-line 5.2 Isolation techniques 5.3 Lightning—a major source of ground potential rise 10 Handling lightning strike current 10 Locating (siting) towers 11 Grounding (earthing) considerations 11 8.1 Grounding impedance 12 8.2 Grounding requirements 13 8.3 Radial counterpoises 13 8.4 Grounding conductor requirements in equipment buildings 14 8.5 Interior equipment ground ring (IEGR) 15 8.6 AC power grounding electrode 15 8.7 Coaxial cable, waveguide, and building entrance panel (BEP) 15 8.8 Communication facility isolation from a lightning induced ground potential rise 16 8.9 Single point ground 16 8.10 Installation of ground rods and bonding requirements 16 Grounding (earthing) tower and equipment 17 9.1 Single point grounding 17 9.2 Ice bridge 17 9.3 Building entrance panel 17 10 Entrance cables 18 11 AC power surge protection 18 11.1 Protecting ac services entering and exiting the building 19 11.2 Surge protective devices (transient voltage surge suppression) 19 12 Personnel safety considerations 20 13 Equipment building lightning protection system 20 Annex A (informative) Bibliography 21 viii Copyright © 2011 IEEE All rights reserved TM APSC FILED Time: 6/10/2015 9:14:01 AM:1692 Recvd 6/10/2015 9:10:59 AM: Docket 14-069-C-Doc 109 IEEE Std -2011 IEEE Guide for the Protection of Communication Installations from Lightning Effects 8.2 Grounding requirements Consider the following items when designing and constructing the grounding system 1) All conductors for the grounding system are to be AWG solid bare tinned copper (SBTC) 2) Use low impedance conductive cement placed around all grounding conductor radial counterpoises at locations where the soil resistivity is greater than 500 meter-ohms at the grounding electrode depth Follow the items below for the installation procedure: a) The trench for the radial counterpoise is to be opened to a depth of a minimum of 457 mm (18 inches) to a maximum of 610 mm (24 inches) or below the frost line b) Place the conductor centered in the trench c) Then use a 50 mm (2 inches) covering of dry, low impedance conductive cement on top of the radial conductor (Moisture from the earth will harden the low impedance conductive cement within one week) d) Then, backfill the trench with removed earth, this will then cover the low impedance conductive cement and radial wire and will level the earth thereby closing the trench NOTE 1— Low impedance conductive cement will not corrode, or crack, and is extremely low in resistivity Other materials might change resistivity depending on moisture content 3) All ground rods for the grounding system are to be stainless steel, copper, or galvanized steel and a minimum of 2.4 m (8 feet) in length and 15.87 mm (5/8 inch) in diameter 4) All bonds to the grounding system in contact with the earth are to be done by exothermic welding or irreversible compression connectors listed for the purpose 5) Provide an external ring ground, which should include ground rods, for the tower and the equipment building The ring ground is to be composed of AWG SBTC conductors placed below the frost line Also provide a minimum of radial counterpoises each 7.6 m (25 feet) in length (see Figure 7) This combination of ring grounds and radial counterpoises provides capacitive coupling of the lightning high frequency current to earth NOTE 2— The scheme described above needs a minimum of 30 m (100 feet) for the total combined length of the radial counterpoises for best results 6) In corrosive environments, consideration should be given to the use of sacrificial magnesium anodes against the effects of corrosion (to protect grounding system) 8.3 Radial counterpoises Place the radial counterpoise conductor in a trench (500–600 mm [18–24 inches] in width) and low resistivity cement, conductive cement, bentonite, or similar material, around the conductor The recommended minimum length of each radial counterpoise conductor is 7.6 m (25 feet) If the desired resistance to earth is not achieved at this length then use longer radial counterpoise conductors in order to obtain the desired resistance objective Bond the radial counterpoise conductor to the tower base and to the 13 Copyright © 2011 IEEE All rights reserved TM APSC FILED Time: 6/10/2015 9:14:01 AM:1692 Recvd 6/10/2015 9:10:59 AM: Docket 14-069-C-Doc 109 IEEE Std -2011 IEEE Guide for the Protection of Communication Installations from Lightning Effects ground ring conductor using an exothermic weld or irreversible compression connectors listed for the purpose (i.e., below or above ground use) The ideal number of radial counterpoises recommended is ten (see Block [B5] The maximum effective length of each radial counterpoises (see Block [B5]) is 24 m (80 feet) each Longer length radial counterpoises will offer little dissipation improvement because the lightning strike current will not remain on the radial counterpoises for much over 24 m (80 feet) In sites with limited space (i.e., real estate limitations or restrictions), the recommended grounding system is, at a minimum, 60 m (200 feet) of grounding conductors This includes a ring ground of 12 m (40 feet) and four radial counterpoises, each 12 m (40 feet) in length Placing a ground rod in rocky soil is not always practical (costly and not efficient with high resistivity soils) The use of radial counterpoises in close contact with the rocky soil and covered by low impedance conductive cement will provide a less expensive and more efficient solution Anchoring the radial counterpoises at the end to minimize movement is recommended In all cases, the use of low impedance conducting cement (or a similar low resistivity material) placed around the radial counterpoises at the time of installation will help reduce the grounding impedance of the radial counterpoise The low impedance conductive cement will harden into concrete both protecting (mechanically) the grounding system (giving it many years of additional life), and giving the system a much better (lower) ground resistance Capacitive radial grounding will dissipate the high frequency current components in lightning Adding ground rods to a radial counterpoise ground wire will not significantly improve the dissipation of the high frequency components in lightning Ground rods are most effective at the origination location (tower ring) of the radial ground and dissipate the low frequency components of lightning, including dc Direct radial counterpoises placed off of the tower ground ring away (opposite direction) from the equipment building Direct counterpoises placed off of the equipment building ground ring away from the tower Radial counterpoises from one structure (i.e., building) may extend around the structure if they not get too close to another structure (i.e., tower) or to the radial counterpoises from that structure If they get too close they could originate voltage differences and increase the GPR 8.4 Grounding conductor requirements in equipment buildings Consider the following requirements for the grounding conductors in equipment buildings  Do not use U-shaped grounding conductor runs  When conduit is required, place all grounding conductors in nonmetallic conduit only If metallic conduit cannot be avoided, bond both ends of the metallic conduit to the grounding conductor  Minimize the length of all grounding conductors Run the conductor as straight as possible avoiding unnecessary bends, loops, and sharp bends The minimum bend radius for a AWG wire is 305 mm (12 inches)  Place grounding conductors through nonmetallic sleeves in floors, walls, ceilings, etc  Keep runs as short as possible 14 Copyright © 2011 IEEE All rights reserved TM APSC FILED Time: 6/10/2015 9:14:01 AM:1692 Recvd 6/10/2015 9:10:59 AM: Docket 14-069-C-Doc 109 IEEE Std -2011 IEEE Guide for the Protection of Communication Installations from Lightning Effects 8.5 Interior equipment ground ring (IEGR) 1) Consider placing an interior equipment ground ring (IEGR) to facilitate common bonding of equipment and to minimize passage of lightning current through equipment (racks) 2) Place the IEGR as close to the same height as the building entrance panel (hatch plate or bulkhead), typically 2–3 m (7–8 feet) 3) Bond the IEGR to the master ground bar (MGB) which is then bonded to the exterior single point ground (SPG) bar 4) Construct the IEGR of AWG stranded or solid bare conductor mounted in an open loop, that is, open at one point, around the perimeter of the room at the recommended height See item 2) 5) Bond items to the IEGR using AWG conductors 6) Bond all equipment frames directly to the MGB when the IEGR is not used 7) When protection against radio-frequency interference is necessary, bond metal objects such as door frames, air conditioners, electrical boxes, cabinets, water pipe, etc., to a closed loop ground ring This ring is typically referred to as a halo ring Do not bond a halo ground ring to fire protection systems or to any electronic equipment whatsoever (see ATIS 0600334 [B3]) 8) The halo ground ring is only bonded to exterior building ring ground through the MGB 9) Bond the MGB directly to the single point ground 8.6 AC power grounding electrode Consider the following items when designing the ac power grounding electrode 1) The ac service grounding must meet the requirements of NFPA 70 National Electrical Code® (NEC®) and any other applicable local code 2) A conductor must be placed from where the ac power service ground is derived to the metallic water pipe system (if present) 3) Bond the ac power service entrance panel board neutral to the tower building’s MGB 4) Bond the ac grounding electrode (ground rod) at the meter to the SPG bar 8.7 Coaxial cable, waveguide, and building entrance panel (BEP) Consider the following items when grounding the cables entering the structure 1) Ground the coaxial antenna cable shield and waveguide to the tower, at the top and bottom of the tower, and every 15 to 20 meters (50 to 75 feet) in between 2) Place the bottom grounding kit for the cable shield at the bend where the coaxial cable and waveguide transition from the vertical to horizontal 3) Route all antenna cable and waveguide into the equipment building through the BEP Ground the cable shields to the BEP 4) The preferred coaxial cable entrance into the equipment building and off of the tower is at ground level for both This design eliminates the need for large copper straps required to ground the BEP, and intercepts the tower magnetic field 5) The BEP at the equipment building is to be grounded to the building ring ground on outside of building and to the MGB inside the building 6) Place SPDs on the coaxial cable just before the coaxial cable enters the BEP 15 Copyright © 2011 IEEE All rights reserved TM APSC FILED Time: 6/10/2015 9:14:01 AM:1692 Recvd 6/10/2015 9:10:59 AM: Docket 14-069-C-Doc 109 IEEE Std -2011 IEEE Guide for the Protection of Communication Installations from Lightning Effects 8.8 Communication facility isolation from a lightning induced ground potential rise Consider the following when addressing the isolation of communication circuits into the facility 1) Isolate from remote ground all wire-line (i.e., metallic) communication facilities, i.e., copper pairs that may enter an equipment building 2) Do not use standard communication pair shunting protection, such as GDT or carbon type primary protectors to protect equipment at lightning GPR locations They are too slow and will allow the lightning surge to pass by and damage equipment Primary solid state hybrid SPD may be used to protect against residual surges (surges passing through the isolation equipment) 3) NOTE—In some cases, primary gas tube protectors in combination with secondary solid state elements may provide adequate protection 4) Ground the metallic shields of wire-line communication cables entering equipment buildings to the single point ground location when wire-line isolation is not used NOTE—NFPA 70 requires the grounding of cable shields entering buildings NFPA 70 also requires primary protection for wire-line conductors 5) When fiber optic cable is used to provide communications services use all-dielectric cable with no metallic strength members or metallic shield Place the cable in a PVC conduit (Schedule 80) with a minimum diameter of 50 mm (2 inches) Locating should be done with electronic (frequencybased) devices or passive reflectors external to the optical fiber cables (see IEEE Std 1590) 8.9 Single point ground Consider the following when designing a single point ground 1) Place a copper ground bar at the single point ground location (in the earth or on the equipment building) 2) Provide suitable access (a hand hole) for the bar installed at the single point ground location to allow for future inspection, maintenance, etc when placing the bar in the earth instead of on the equipment building 3) Damage to equipment in buildings may be minimized by providing a Faraday cage in the equipment building’s concrete walls utilizing the rebar within the concrete A Faraday cage is established by electrically connecting the rebar cage, ¼-inch rebar at every rebar intersection, with 203 mm (8 inch) rebar spacing on all four building sides including the roof, and bonded to ring ground 4) Use tinned copper bars when the ground bars are placed in exterior locations Tinning provides corrosion protection All connections to ground bars are to be made using two-hole lugs 8.10 Installation of ground rods and bonding requirements Consider the following when installing ground rods and determining bonding requirements 1) Place all ground rods in undisturbed soil and below the frost line 2) Provide suitable access (a hand hole) for the ground rods placed at each corner of the ground rings The hand hole will allow future inspection, maintenance, etc., of the ground rods without digging 3) Bond external ring grounds to any metal object or structure, including fences, within m (6 feet) of the ground ring 16 Copyright © 2011 IEEE All rights reserved TM APSC FILED Time: 6/10/2015 9:14:01 AM:1692 Recvd 6/10/2015 9:10:59 AM: Docket 14-069-C-Doc 109 IEEE Std -2011 IEEE Guide for the Protection of Communication Installations from Lightning Effects 4) Bond any fences, including fence posts, to the ground ring 5) Bond openings across the fence (i.e., gate posts) to the ground ring 6) Place a flexible bonding strap from each gate post to the movable gate section(s) Grounding (earthing) tower and equipment 9.1 Single point grounding Single point grounding (typically at the BEP) helps minimize equipment damage from lightning The GPR resulting from lightning is a wave of voltage rise, or current surge that passes through a grounding system If all equipment is bonded to the grounding system at one location (single point), then every metallic object rises and falls in potential together Single point grounding also helps to minimize touch potential thus increasing the level of personnel safety 9.2 Ice bridge The ice bridge is to be isolated from the tower with an isolating bracket and/or air space as the ice bridge leaves the tower (see “R56 Manual” [B30]) Angle the ice bridge upward from the tower to the building so that the tower-end is lower than the building-end The ice bridge is to be grounded to the tower grid via its support legs only The objective is to eliminate a path for the lightning current toward the equipment building as well as minimizing possibility of current loops using the ice bridge (see “R56 Manual” [B30]) 9.3 Building entrance panel Coaxial cables, waveguide, antenna wires, etc typically enter the equipment building through a building entrance panel (also called a bulkhead panel or waveguide hatch) The BEP is made out of solid copper or stainless steel The installation and proper engineering design of the BEP reduces the risk that lightning will enter the equipment building on any entrance cables coming from the antenna tower The height above ground level at which the tower cables pass into the building through the BEP is comparable to a voltage divider circuit As an example, if the voltage over the height of a tower struck by lightning is approximately 250 kV, at one tenth the tower height, the voltage on the tower cables would be about 25 kV Consequently, the best location for the BEP is at the base of the tower in order to ensure the lowest level of voltage on the entrance cables This cable entrance at ground level also enables all equipment in the building to be grounded at the base or floor level This results in minimum equipment voltage stress and maximum safety to personnel If the BEP is placed high above the base of the tower (4.5 m to m [15 feet to 20 feet]), then all equipment grounding within the building must be made at this height Thus, equipment racks must be isolated from the floor and grounded at ceiling (BEP) level to minimize lightning current from passing through the equipment in order to get to ground Grounding of the BEP to building ground requires the use of two 2/0 AWG (or coarser) conductors with sufficient separation between the two to minimize mutual impedance 17 Copyright © 2011 IEEE All rights reserved TM APSC FILED Time: 6/10/2015 9:14:01 AM:1692 Recvd 6/10/2015 9:10:59 AM: Docket 14-069-C-Doc 109 IEEE Std -2011 IEEE Guide for the Protection of Communication Installations from Lightning Effects Bond the exterior of the building entrance panel to the coaxial cables and/or waveguides and to any other metal structure, such as a transmission line support frame (ice bridge) Connect directly to the external building grounding system with a lead in a downward direction All coaxial cables and/or waveguides are to be bonded to the tower’s grounding structure Bond the interior of the building entrance panel to the interior grounding system 10 Entrance cables A lightning strike to a grounding system produces an elevated GPR Any equipment bonded to this grounding system, and also connected to wire-line communications, may be damaged from outgoing current seeking remote earth Personnel working at this equipment may be susceptible to harm because they could be in the current path of this outgoing current The equipment damage from a lightning strike may not be immediate Sometimes equipment is weakened by stress and primed for failure at some future time This condition is called latent damage and leads to premature mean time between failures (MTBF) of the equipment The best engineering design is the use of all-dielectric optical fiber cable for communications A properly engineered and installed all-dielectric optical fiber cable will provide immunity from most of the effects of fault-produced GPR and induction Isolation, then, is no longer a requirement since physical isolation is inherent in the optical fiber itself The all-dielectric optical fiber cable may need to be placed in PVC conduit if it is necessary to protect it from rodents However, when wire-line facilities are used, an engineering design solution to protect this equipment is to isolate the wire-line communications from remote earth This is accomplished using optical isolators and or isolation transformers This equipment is housed together, mounted on a non-conducting surface in a nonconducting cabinet, and is called the high-voltage interface (HVI) The HVI isolates the equipment during a GPR and minimizes any current flow from a higher potential grounding system to a lower potential grounding system providing protection to personnel and equipment from the effects of current flow on the wire-line Other isolation solutions involving microwave radio are also possible 11 AC power surge protection The building ac power supply is also susceptible to the effects of a GPR Since the neutral and ground wire of a power entrance facility must be bonded (required by NFPA 70) to building ground, a rise in potential of the grounding system will place a surge on the neutral and ground wire This surge will radiate, not only throughout the building, but also away from the building on the incoming power cables In some cases, the elevated potential of the neutral and ground wire may actually be greater than the potential of the power (phase) wires The resulting surge on the power wires may damage building equipment power supplies, other powered equipment parts, or weaken equipment parts for future failure (latent damage) However, the facility entrance power supply is much more robust a system than the communications system, and its protection using a shunting system is very effective (in most situations) in protecting the associated building equipment Provide Class C type SPDs that contain all-mode discrete component (L-L, L-N, L-G, and N-G) on the line side of the transfer switch for both the ac service entering the building and the generator service 18 Copyright © 2011 IEEE All rights reserved TM APSC FILED Time: 6/10/2015 9:14:01 AM:1692 Recvd 6/10/2015 9:10:59 AM: Docket 14-069-C-Doc 109 IEEE Std -2011 IEEE Guide for the Protection of Communication Installations from Lightning Effects In addition to a protected power entrance facility, there may also be the need to protect secondary ac power panels throughout the building with Class C or Class B type SPDs containing all-mode discrete components This protection is to minimize the magnitude of the power surge that may get past the main power panel to address services that may leave the building for lights and security cameras 11.1 Protecting ac services entering and exiting the building Provide SPDs that contain all-mode discrete component (L-L, L-N, L-G, and N-G) on the line side of the transfer switch for both the ac service entering the building and the generator service If no transfer switch exists, provide SPDs that contain all-mode discrete components on the ac service entering the building Provide SPDs that contain all-mode discrete components on any ac service exiting the building 11.2 Surge protective devices (transient voltage surge suppression) SPDs should be installed at the service entrance or in the service entrance panel on the load side of the main fuse or breaker that is suitable for location in Category B environment The SPD should meet the national requirement for installation in this location In most applications the device should have a lightning discharge current capability of 10 kA or a value appropriate to the expected lightning risk Critical circuits and equipment should be protected with SPDs suitable for Category B or Category C environment in accordance with IEEE Std C62.41.1 [B23] SPDs suitable for Category C environment use should be limited to areas that are at least 10m distance from the service entrance panel (See UL 1449-2006 [B35] for additional information on SPDs) Consider the following items when selecting SPDs (TVSS): The SPD should be chosen to provide surge voltage protection to the downstream equipment a) Service entry protection panels  Service entry protection panel must be UL 1449 [B35] listed and tested to IEEE Std C62.451992 [B25]  Capability shall be bi-directional and treat both positive and negative impulses  For low-voltage ac power circuits the SPD installed at the entrance panel should have a protective level rating low enough to prevent insulation failure and misoperation of the equipment it is intended to protect (at least an maximum continuous operating voltage [MCOV] rating of 150 V for 120 V service) and a protective level rating of less than kV Effective response time shall be 20 nanoseconds or less to 8/20 μs waveform  Suppression shall be line to neutral, except delta configurations b) Sub-protection panels  Sub-protection panels shall operate as a totally coordinated system with the service protection panel and shall be listed to the latest issue of UL 1449  Unit shall not short circuit power flow that would cause an interruption of power to load  Downstream SPDs should have a current impulse discharge rating of at least 1.5 kA and a protective level rating low enough to prevent insulation failure and misoperation of the 19 Copyright © 2011 IEEE All rights reserved TM APSC FILED Time: 6/10/2015 9:14:01 AM:1692 Recvd 6/10/2015 9:10:59 AM: Docket 14-069-C-Doc 109 IEEE Std -2011 IEEE Guide for the Protection of Communication Installations from Lightning Effects equipment it is intended to protect (at least an MCOV rating of 150 V for 120 V service) Effective response time shall be nanoseconds or less to 8/20 μs waveform  Suppression shall be line to neutral, line-to-line, line-to-ground, and neutral-to-ground using discrete components, except delta configurations 12 Personnel safety considerations At least the following recommendations should be considered for the safety of personnel: Personnel should not work on a tower or in the equipment building during an electrical storm The use of SPDs with failure indication is recommended and any noted damage to SPD (TVSS) equipment in the equipment building shall be repaired or replaced immediately prior to any other work attempted Consideration should be given for a minimum of two maintenance personnel working together at locations prone to lightning strike activity 13 Equipment building lightning protection system Consider the following when designing a lightning protection system for the equipment building Protect equipment buildings with a traditional lightning protection system using air terminals, etc., when they are considered exposed to a direct lightning strike Follow NFPA 780 and/or UL 96A [B34] to protect exposed equipment buildings 20 Copyright © 2011 IEEE All rights reserved TM APSC FILED Time: 6/10/2015 9:14:01 AM:1692 Recvd 6/10/2015 9:10:59 AM: Docket 14-069-C-Doc 109 IEEE Std -2011 IEEE Guide for the Protection of Communication Installations from Lightning Effects Annex A (informative) Bibliography Bibliographical references are resources that provide additional or helpful material but not need to be understood or used to implement this guide Reference to these resources is made for informational use only [B1] Anderson, R B and Eriksson, A J., “Lightning Parameters for Engineering Applications,” Electra No 69, pp 65–102, Mar 1980 [B2] ATIS 0600321, Electrical Protection for Network-Operator Type Equipment Positions, Aug 2010 [B3] ATIS 0600334, Electrical Protection of Communications Towers and Associated Structures, Nov 2008 [B4] ATIS 0600338,-2004, Electrical Coordination of Primary and Secondary Surge Protection for Use in Telecommunications Circuits, 2004 [B5] Block, R R., The Grounds for Lightning and EMP Protection, 2nd edition Minden, NV: PolyPhaser Corp., 1993 [B6] Brashear, K., Lightning and Surge Protection of Modern Electronic Systems, San Antonio, TX: ILD Technologies, LLC , 2007 [B7] Cohen, R L., et al., How to Protect Your House and Its Contents from Lightning IEEE Guide for Surge Protection of Equipment Connected to AC Power and Communication Circuits New York, NY: IEEE Press, 2005 10 [B8] DeCarlo, B A., Rakov, V A., Jerauld, J E., Schnetzer, G H., Schoene, J., Uman, M A., Rambo, K J., Kodali, V., Jordan, D M., Maxwell, G., Humeniuk, S., and Morgan, M., “Distribution of Currents in the Lightning Protective System of a Residential Building—Part I: Triggered-Lightning Experiments,” IEEE Transactions on Power Delivery, vol 23, no 4, pp 2439–2446, Oct 2008 [B9] Duckworth, Jr., E M., “Guide for Protection of Equipment and Personnel from Lightning,” Journal of Performance of Constructed Facilities, Aug 2002 [B10] Duckworth, Jr., E M and Duckworth J S., “GPR-Expert—Ground Potential Rise Protection Using a High Voltage Interface.” http://gpr-expert.com/ June 15, 1998 [B11] Frydenlund, M M., Lightning Protection for People and Property New York, NY: Van Nostrand Reinhold, 1993 [B12] Hart, W C and Malone, E W., Lightning and Lightning Protection Gainesville, VA: Interference Control Technologies, Inc., 1988 [B13] IEC 62305-1-2006, Protection Against Lightning—Part 1: General Principles 11 [B14] IEC 62305-2-2006, Protection Against Lightning—Part 2: Risk Management [B15] IEC 62305-3-2006, Protection Against Lightning—Part 3: Physical Damage to Structures and Life Hazard ATIS publications are available from the Alliance for Telecommunications Industry Solutions, 1200 G Street NW, Suite 500, Washington, DC 20005, USA (http://www.atis.org/) 10 IEEE publications are available from the Institute of Electrical and Electronics Engineers, 445 Hoes Lane, Piscataway, NJ 08855, USA (http://standards.ieee.org/) 11 IEC publications are available from the Sales Department of the International Electrotechnical Commission, Case Postale 131, 3, rue de Varembé, CH-1211, Genève 20, Switzerland/Suisse (http://www.iec.ch/) IEC publications are also available in the United States from the Sales Department, American National Standards Institute, 11 West 42nd Street, 13th Floor, New York, NY 10036, USA 21 Copyright © 2011 IEEE All rights reserved TM APSC FILED Time: 6/10/2015 9:14:01 AM:1692 Recvd 6/10/2015 9:10:59 AM: Docket 14-069-C-Doc 109 IEEE Std -2011 IEEE Guide for the Protection of Communication Installations from Lightning Effects [B16] IEC 62305-4-2006, Protection Against Lightning—Part 4: Electrical and Electronic Systems Within Structures [B17] IEEE, IEEE Standards Dictionary: Glossary of Terms & Definitions, New York, NY: Institute of Electrical and Electronics Engineers, 2008 12 [B18] IEEE Std 80™-2000, IEEE Guide for Safety in AC Substation Grounding [B19] IEEE Std 81™-1983, IEEE Guide for Measuring Earth Resistivity, Ground Impedance, and Earth Surface Potentials of a Ground System [B20] IEEE Std 142™-2007, Recommended Practice for Grounding of Industrial and Commercial Power Systems [B21] IEEE Std 1100™-2005, Recommended Practice for Powering and Grounding Electronic Equipment [B22] IEEE Std 1428™-2004, IEEE Guide for Installation Methods for Fiber-Optic Cables in Electric Power Generating Stations and in Industrial Facilities [B23] IEEE Std C62.41.1™-2002, Guide on the Surge Environment in Low-Voltage (1000 V and Less) AC Power Circuits [B24] IEEE Std C62.43™-2004, IEEE Guide for the Application of Surge Protectors Used in Low-Voltage (Equal to or Less Than 1000 V, RMS, or 1200 V, DC) Data, Communications, and Signaling Circuits [B25] IEEE Std C62.45™-1992, IEEE Guide on Surge Testing for Equipment Connected to Low-Voltage AC Power Circuits [B26] ITU-T K.11 (01/2009), Principles of Protection Against Overvoltages and Overcurrents 13 [B27] ITU-T K.36 (05/1996), Selection of Protective Devices [B28] Lightning and Insulator Subcommittee of the T&D Committee, “Parameters of Lightning Strokes: A Review,” IEEE Transactions on Power Delivery, Vol 20, No 1, pp 346–358, Jan 2005 [B29] Ma, J and Dawalabi, F P., “Modern Computational Methods for the Design and Analysis of Power System Grounding,” Proceedings of Powercon ’98 International Conference on System Technology, vol 1, pp 122–126, Aug 1998 [B30] Motorola14, 15 Communications Enterprise, “The R56 Manual,” Standards and Guidelines for Communications Sites Document number 68-81089E50, 2005 [B31] National Lightning Safety Institute, Lightning Costs and Losses from Attributed Sources http://www.lightningsafety.com/nlsi_lls/nlsi_annual_usa_losses.htm, Apr 2008 [B32] Rand, K R., Lightning Protection and Grounding Solutions for Communication Sites Hayden, ID: PolyPhaser Corp., 2000 [B33] Sunde, E D., Earth Conduction Effects in Transmission Systems New York, NY: Dover Publications, Inc., 1968 [B34] UL 96A, Installation Requirements for Lightning Protection Systems 16 [B35] UL 1449-2006, Standard for Surge Protective Devices, 3rd edition [B36] Uman, M A and Rakov, V A., “A Critical Review of Nonconventional Approaches to Lightning Protection,” Bulletin of the American Meteorological Society, Vol 83, pp 1809–1820, Dec 2002 12 IEEE publications are available from the Institute of Electrical and Electronics Engineers, 445 Hoes Lane, Piscataway, NJ 08854, USA (http://standards.ieee.org/) 13 ITU-T publications are available from the International Telecommunications Union, Place des Nations, CH-1211, Geneva 20, Switzerland/Suisse (http://www.itu.int/) 14 Motorola is a registered trademark of Motorola Inc 15 The following information is given for the convenience of users of this standard and does not constitute an endorsement by the IEEE of these products Equivalent products may be used if they can be shown to lead to the same results 16 UL standards are available from Global Engineering Documents, 15 Inverness Way East, Englewood, CO 80112, USA (http://global.ihs.com/) 22 Copyright © 2011 IEEE All rights reserved TM APSC FILED Time: 6/10/2015 9:14:01 AM:1692 Recvd 6/10/2015 9:10:59 AM: Docket 14-069-C-Doc 109 IEEE Std -2011 IEEE Guide for the Protection of Communication Installations from Lightning Effects Annex B (informative) Lightning protection guide checklist for risk management B.1 Key considerations for the application of this Guide  Use current division and current blocking to control the dissipation of lightning strike current on an antenna tower grounding system through multiple paths  Separate the antenna tower from the equipment building by a minimum of m (30 feet)  Use only a single point grounding system for the equipment building  Use a bulkhead panel/waveguide hatch for all coaxial cable entry into the equipment building  Coordinate the location of the (1) bulkhead panel bond, (2) power and telecommunications entry bond, (3) bond between antenna and equipment building, at the single point ground connection, and (4) building master ground bar  Use ac power surge protection at main power entry and critical secondary panels B.2 How to use this Guide Use the NFPA 780 risk assessment guidelines to determine the lightning risk to the structure Additionally, in order to determine the potential for equipment damage or destruction and personnel injury or death from a lightning strike, perform the following risk evaluation Count the number of items from the list below that describe conditions at your location:  Lightning damage has occurred here before  Personnel are located here and use the equipment at this location  This location is associated with an antenna tower that is within 15 m (50 feet)  This location is in an area of the country that has 30 or more thunderstorm days per year  This location uses ac power, and does not have surge protected power panels  This location uses wire-line telecommunication services which have not been isolated using optical isolation or isolation transformers  All equipment in this location is not bonded together at one single point on the building grounding system  This location has coaxial cables that come directly into the building without going through a bulkhead panel/waveguide hatch  The associated antenna tower at this location does not have a grounding system made up of at least 60 m (200 feet) of buried bare ground conducting wire with multiple paths (minimum of 5, each 12 m [40 feet] in length) away from tower base  This location has coaxial cables that enter at ceiling height (4.5 m to m [15 to 20 feet] above ground level), and all equipment grounding is done at floor level or below 23 Copyright © 2011 IEEE All rights reserved TM APSC FILED Time: 6/10/2015 9:14:01 AM:1692 Recvd 6/10/2015 9:10:59 AM: Docket 14-069-C-Doc 109 IEEE Std -2011 IEEE Guide for the Protection of Communication Installations from Lightning Effects The number of items above that apply indicates your equipment and personnel risk: Number of Items or fewer to to or more Equipment and Personnel Risk Low Moderate Severe Critical 24 Copyright © 2011 IEEE All rights reserved TM APSC FILED Time: 6/10/2015 9:14:01 AM:1692 Recvd 6/10/2015 9:10:59 AM: Docket 14-069-C-Doc 109 IEEE Std -2011 IEEE Guide for the Protection of Communication Installations from Lightning Effects Annex C (informative) Basic concepts for lightning protection of structures This informative annex presents basic concepts for the electrical protection recommendations associated with the protection of structures housing communication equipment from the effects of lightning Protection of towers are excluded from this annex Lightning is a natural phenomenon that causes millions of dollars in damages to communication equipment each year due to high-voltage surges and transients There is no practical effective way to protect structures housing communication equipment from direct lightning strikes However these structures may be protected by observing the following items: 1) Capture the lightning strike 2) Conduct current to ground (earth) 3) Dissipate current into ground 4) Bond all grounding conductors 5) Protect from surges on incoming ac power line and on telecommunications (data/signal line) A systematic approach includes grounding and bonding, lightning and surge protection to safeguard and protect the structures and the equipment inside them The first item involves capturing the lightning strike at the strike point In order to accomplish this capture, the structure must have a dedicated lightning protection system that includes air terminals at key locations The second item involves directing the lightning current to ground (earth) via the down conductors The down conductors are cables designed to conduct safely the lightning current to earth The third item deals with dissipating the lightning current into the structure’s low impedance grounding system A low resistance grounding system is not sufficient since the lightning surges are impulses of very short time duration The fourth item deals with the electrical bonding of all the separate equipment grounding points (telecommunications, electrical, and metal objects) to create one equipotential ground plane During a lightning strike the equipotential ground plane will ensure that all the equipment will rise to the same potential, as the ground potential goes up, thus minimizing equipment damages The fifth item involves the electrical protection of all the entry points (ac power line and telecommunications) to the facility This involves placing SPD on all outside lines that come into the structure These lines, whether aerial (overhead) or underground, can bring the lightning surges into the structure unless properly protected 25 Copyright © 2011 IEEE All rights reserved TM APSC FILED Time: 6/10/2015 9:14:01 AM:1692 Recvd 6/10/2015 9:10:59 AM: Docket 14-069-C-Doc 109 IEEE Std -2011 IEEE Guide for the Protection of Communication Installations from Lightning Effects Annex D (informative) Power-line isolation: theory and application D.1 LGPR and equipotential planes The ideal prevention of LGPR is provided by an equipotential plane This ideal can be approximated within shelters and cabinets that are configured with a single point ground However, the ac power line provides a reference to lower potential ground during a LGPR event The safety ground between the shelter or cabinet and the power neutral ground presents a high inductance relative to the rise time of the LGPR wave form Vertical grounds characteristic of most shelters and all cabinets also react inductively to the mid-range frequencies of lightning (See DeCarlo et al [B8] for additional information.) Consequently, the bi-directional conductivity of grounding and the signal cable or antenna SPDs create a secondary fault path on the power circuits between the shelter or cabinet and the power neutral ground Refer to 5.2.2 and Figure Enhanced radial grounding at a tower site will mitigate the LGPR severity, but creating an equipotential plane between the shelter and power-neutral grounds is not feasible Blocking the fault current through the ac service by preemptive disconnection of the ac power is the only certain protection for this fault path D.2 LGPR detection and isolation activation The ground strike discharge radiates high voltage through the earth’s surface, referred to as lightning ground potential rise (LGPR) The severity and range of earth-bound LGPR is determined by the lightning current characteristics and soil resistivity The LGPR radiated by approaching lightning storms is detectable several miles distant by a grounded dipole or flat-plate detector The detection sensitivity is adjustable to limit the detection range to threatening conditions The detector controls a contactor in series with the ac service The response time of the contactor activation must be less than 20 ms to preempt threats posed by near-proximity strikes D.3 Back-up power and rectifier implications Continuous operation is maintained by standby power systems (battery plant and generator if present) until ac power is automatically restored after the threat has passed The disconnection period is selectable Subsequent lightning threats during the disconnection period refresh the count-down timer To minimize generator cycling, the disconnection period may be extended, the isolation timing can be coordinated with the automatic transfer switch (ATS), and generator timers and the contactor may be installed on the load side of the generator 26 Copyright © 2011 IEEE All rights reserved TM APSC FILED Time: 6/10/2015 9:14:01 AM:1692 Recvd 6/10/2015 9:10:59 AM: Docket 14-069-C-Doc 109 IEEE Std -2011 IEEE Guide for the Protection of Communication Installations from Lightning Effects Re-connection of the ac service should be timed at the voltage cross-over to mitigate power recovery transients and in-rush current D.4 Power line transient protection Direct or near-proximity strikes to power lines induce severe transients that may overwhelm protective systems Detection of LGPR radiated by approaching lightning storms allows preemptive disconnection of the ac service, effectively isolating the site equipment from lightning induced power-line transients AC power is automatically re-connected after the power stabilizes within selective power quality thresholds 27 Copyright © 2011 IEEE All rights reserved ...APSC FILED Time: 6 /10 /2 015 9 :14 : 01 AM: Recvd 6 /10 /2 015 9 :10 :59 AM: Docket 14 - 069- C- Doc 10 9 TM 10 9 APSC FILED Time: 6 /10 /2 015 9 :14 : 01 AM: Recvd 6 /10 /2 015 9 :10 :59 AM: Docket 14 - 069- C- Doc IEEE... reserved APSC FILED Time: 6 /10 /2 015 9 :14 : 01 AM: Recvd 6 /10 /2 015 9 :10 :59 AM: Docket 14 - 069- C- Doc 10 9 APSC FILED Time: 6 /10 /2 015 9 :14 : 01 AM: Recvd 6 /10 /2 015 9 :10 :59 AM: Docket 14 - 069- C- Doc 10 9 IEEE... service 18 Copyright © 2 011 IEEE All rights reserved TM APSC FILED Time: 6 /10 /2 015 9 :14 : 01 AM :16 92 Recvd 6 /10 /2 015 9 :10 :59 AM: Docket 14 - 069- C- Doc 10 9 IEEE Std -2 011 IEEE Guide for the Protection