J2l FAA-STD-019G - LPGBS 2024.pdf

FAA-STD-019G

January 16, 2024

DEPARTMENT OF TRANSPORTATION

FEDERAL AVIATION ADMINISTRATION

STANDARD

LIGHTNING AND SURGE PROTECTION,

GROUNDING, BONDING, AND SHIELDING

REQUIREMENTS FOR

FACILITIES AND ELECTRONIC EQUIPMENT

ii

This Page Intentionally Left Blank iii

FOREWORD

1. Construction of Federal Aviation Administration (FAA) operational facilities and the electronic equipment installed therein shall conform to this standard. This standard defines minimum requirements for FAA facilities. When specific needs of a facility exceed these minimum requirements, the facility design and construction shall meet the specific needs.

The equipment type, configuration, and location along with the configuration of site structures and environmental/weather conditions influence these needs.

2. The requirements herein reflect lessons learned from investigation and resolution of malfunctions and failures experienced at field locations. The FAA thus considers these requirements the minimum necessary to harden sites sufficiently for the FAA missions – to prevent delay or loss of service, to minimize or preclude outages, and to enhance personnel safety. Further, the requirements herein are coordinated with industry standards, and in some cases exceed industry standards where necessary to meet the FAA missions.

3. The use of “shall” or verbs such as “provide,” “construct,” “weld,” or “connect” indicates mandatory compliance. Deviations are permissible in cases when implementation of certain requirements is not technically feasible, and in such cases, the FAA shall submit a National Airspace System (NAS) Change Proposal (NCP) with justification and technical documentation, and receive approval by the NAS Configuration Control Board (CCB).

4. The format and content requirements of this standard are in accordance with FAA-STD-068, and the grammar and style are in accordance with the Government Printing Office (GPO) Style Manual.

iv v

Change History

1. Originator Name and Address AJW-22, Power Services Group

2. [ ] Proposed 3. Code Identification 4. Document No. _______

Washington, DC [X] Approved 5. Code Identification 6. DCN No.

7. System Designation 8. Related ECR/NCP No.

9. Contract No. 10. Contractual Activity N/A

11. Product Integration Plan 12. Effectivity

This notice informs recipients that the standard identified by the number (and revision letter) shown in block 4 has been changed. The pages changed by this DCN (being those furnished herewith) carry the same date as the DCN. The page numbers and dates listed below in the summary of changed pages, combined with non-listed pages of the original issue of the revision shown in block 4, constitute the current version of this specification.

13. Version 14. Section changed S* A/D* 15. Date 019F 4.5.2(d) – correct typo. 4/4/2019

019F 4.6.2.3(a) – provide description on how to size the SPD ground conductor in small panels where the GEC size is smaller than the maximum conductor size allowed by the manufacturer.

4/4/2019

019F 5.2.4(b) and (c) – update for clarity and consistency - grounding of separately derived systems in ATCT environment.

4/4/2019

019f Figure 19 – update figure for clarity. 4/4/2019

019F Chg 2 Change exothermic weld policy in staffed operation facility. Connections that meet the requirements of Underwriters Laboratories UL467 and UL96 listed irreversible compression type bonding connection is permitted for use in lightning protection system application. Changes applied to section 4.2.3.1, 4.2.3.2, 4.3.5.1, 4.3.7.2, and 4.7.3.3.

8/23/2019

019F Chg 2 Figure 3 – update figure, remove specific reference to exothermic weld type per policy change above.

8/23/2019

019F Chg 2 Table 5 – add color code information for ground cables from the main ground plate to the earth electrode system (EES) and add color coding for ground cable from the supplemental ground plate to the EES.

8/23/2019

019F Chg 3 4.4.4.2c and e – add missing conductor sizes that were in advertently dropped from previous version of this document.

7/14/2020

019F Chg 3 5.3.6 – add electrical continuity bonding exception: If bonding jumper for sections of stairs, ladders, or platforms causes a safe-climbing hazard, the requirement is waived.

7/14/2020

019G Definitions. – added definitions for “air terminal” and “mullion.” 01/16/2024

019G 4.2.2 - added note to table of dissimilar metals, for information purposes only. 01/16/2024

019G 4.2.3.4.3 – updated table and figure – color codes + order of assembly for bolted connections.

01/16/2024

019G 4.4.4 - Figure 4 – updated figure – service disconnect rack. 01/16/2024

019G 4.5.2d – Added exception for parity matched transformer grounding details. 01/16/2024

019G 4.5.4 – deleted exceeding NEC minimum requirements concerning raceway grounding bushings.

01/16/2024

019G 4.6.2a – added details of service disconnect means SPD wiring sizes, connections, and disconnect/overcurrent protection.

01/16/2024

019G 4.6.2.2 – editorial changes. 01/16/2024

019G 4.6.3 - added exception note for placement of SPDs on control and data lines. 01/16/2024

019G 4.7.3.1.4 – replaced section to clarify proper multipoint connection methods from plate and bus to equipment.

01/16/2024

019G 4.7.3.1.6 – Added Note 3 in Table 5 on topic of marking and tracing conductors in cable tray.

01/16/2024

019G 5.2.2.2.2 – added note on use of solid copper rod in place of a down conductor when running the LP conductor outside a mullion.

01/16/2024

019G 5.2.4b - Added exception for parity matched transformer grounding details. 01/16/2024 vi

019G 5.3.2 - added detailed section on lightning protection requirements for small, medium, and large antenna towers, including radomes.

01/16/2024

019G 5.3.8.2 - added detail on grounding a fence passing under an overhead power line. 01/16/2024

019G 5.3.9 - Added clarification of requirements for lightning protection of solar photovoltaic arrays.

01/16/2024

019G 5.6.5.1 – added note to require electronic equipment to have an external grounding pad or other special design installation to provide proper two-hole grounding lug connection per NEBS.

01/16/2024

019G 5.6.5.5.2 – Editorial changes. 01/16/2024 vii

TABLE OF CONTENTS

Paragraph Page

1 SCOPE

1.1 Applications

1.2 Tailoring of Mandatory Requirements

1.3 Purpose

1.4 Content Organization

2 APPLICABLE DOCUMENTS

2.1 General

2.2 Government Documents

2.3 Non-Government Documents

3 DEFINITIONS

4 GENERAL REQUIREMENTS

4.1 Introduction

4.2 Bonding Requirements

4.3 Lightning Protection System Requirements

4.4 Earth Electrode System (EES)

4.5 National Electric Code - Power Distribution System Grounding Compliance

4.6 Surge Protection Device (SPD) Requirements

4.7 Grounding and Bonding for NAS Electronic Equipment Areas

4.8 Shielding Requirements

4.9 Electrostatic Discharge (ESD) Requirements

5 DETAILED REQUIREMENTS

5.1 Introduction

5.2 Airport Traffic Control Tower (ATCT) Facilities

5.3 Lightning Protection System – Special Conditions

5.4 Facility Transient Protection – Special Conditions

5.5 Single Point Ground System (SPG) – Special Conditions

5.6 NAS Electronic Equipment – Interface and Procurement Requirements

5.7 Surge Protective Device (SPD) – Equipment Specification Requirements

5.8 Electrostatic Discharge (ESD) Protection – Interface and Specification Requirements

5.9 Electromagnetic Compatibility Requirements

6 NOTES

6.1 Acronyms and Abbreviations

6.2 Guidelines and Reference Notes

6.3 Version Cross-Reference

6.4 Bibliography

viii

List of Figures

Figure Page Figure 1. Order of Assembly for Bolted Connections Figure 2. Lightning Protection System Main Conductor Connections – Illustrative Example Figure 3. Main and Down Conductor Termination to EES – Illustrative Example Figure 4. Typical Service Rack EES Installation – For Illustrative Purposes Only Figure 5. Grounding Trench Detail Figure 6. Ground Dissipation Plate Detail Figure 7. Bonding of Grounding Conductor to Conduit or Equipment Figure 8. SPD Location Diagram - Close Proximity Allowance Decision Tree Figure 9. Typical Facility Grounding System Figure 10. Multipoint Ground Conductor Size Determination Figure 11. Typical Electronic Equipment Grounding Methods Figure 12. Grounding of Overall Cable Shields to Connectors and Penetrating Walls Figure 13. Grounding of Overall Cable Shield to Terminal Strip Figure 14. Airport Traffic Control Tower – Typical Floor Levels Figure 15. Typical Electronic Equipment Grounding Riser Diagram for ATCT (Preferred

Method) Figure 16. Typical Electronic Equipment Grounding Riser Diagram for ATCT (Alternative

Method) Figure 17. Typical Classification of FAA Antenna Towers Figure 18a. Lightning Protection for Medium Size Three-Sided Tower without Platform, Typically a Glide Slope Tower Figure 18b. Typical Lightning Protection for Towers and RTR with Antenna Platforms Figure 19. Lightning Protection for Radomes and Radar Antenna Platforms Figure 20. Fence Grounding Figure 21. Buried Guard Wire Detail for Underground Cables or Cable Duct Banks Figure 22. Single-Point Ground System Installation - Illustrative Example Figure 23. Lines and Cables Requiring Protection Figure 24. Bonding of Connectors to Mounting Surface Figure 25. Single-Point Ground Bus Bar Installation in Rack or Cabinet

Note. Colors in figure illustrations distinguish the fundamental elements of the grounding system concept and do not represent color-coding or labeling requirements of this standard.

List of Tables

Table Page Table 1. Mechanical Bonds Between Dissimilar Metals Table 2. Connection Torque Requirements for Bolted Bonds Table 3. Size of Electronic Multipoint Ground Interconnecting Conductors Table 4. Ground Plate Specification Requirements Table 5. Grounding Conductor Insulation Color Codes Table 6. Minimum Separation Distance between Signal and Power Conductors ix

Table 7. ATCT MPG Configuration – Parallel Conductor Complements Table 8. Summary Table with Antenna Tower Lightning Protection Requirements Table 9. Electronic Equipment Power Entrance SPD--Surge Current Lifetime Rating Table 10. Electronic Equipment Power Entrance SPD--Slope Resistance (Rslope) Table 11. Electronic Equipment Power Entrnace SPD--Voltage Protection Rating (V3) Table 12. Power Distribution Equipment SPD – Surge Current Lifetime Rating Table 13. Power Distribution Equipment SPD - Slope Resistance (Rslope) Table 14. Power Distribution SPD Voltage (V3) Protection Rating

1 SCOPE

This standard establishes design, procurement, installation, construction, and evaluation standards for lightning protection, transient surge protection, grounding, bonding, shielding configurations and procedures, and control of electrostatic discharge (ESD).

1.1 Applications

The requirements of this standard are mandatory for both new facilities and modifications and upgrades to existing facilities, new equipment installations, and new electronic equipment procurement used in the National Airspace System (NAS) facilities.

The use of the term “facilities” herein can differ from the manner in which it is frequently used in other Federal Aviation Administration (FAA) documents. In this standard, facilities may refer to an entire building, tower, interior or exterior system(s), or portions thereof which support the NAS and its operation. The physical proximity of the system(s) or equipment typically defines a single facility, while significant physical separation of the system or equipment defines separate facilities.

This standard covers government owned or leased property and “facilities.”

a. Contractor-Owned Equipment Interface. The interface between contractor-owned equipment or electronic equipment not used for operational purposes, such as administrative local area network (LAN), administrative telephone, and the operational NAS facilities shall be in accordance with this standard.

1.2 Tailoring of Mandatory Requirements

The FAA recommends that the Office of Primary Responsibility (OPR) is contacted to obtain technical guidance on the applicability of requirements herein for modifications, upgrades, and new equipment installations in existing facilities.

a. Application for Previously Funded Programs. This standard is not mandatory for programs funded prior to the issue date of this standard, nor is it mandatory for construction contracts associated with programs funded prior to the issue of the standard. Application of this standard is at the discretion of the user for programs funded prior to the issue of the standard.

b. Mandatory Applications. The OPR can mandate the use of this standard for programs started before the issue date of this standard, if funding is provided.

1.3 Purpose

The requirements of this standard provide a systematic approach to minimize electrical hazards to personnel, and minimize electromagnetic interference (EMI) that can cause damage to facilities and electronic equipment from lightning, transients, ESD, and power faults.

1.4 Content Organization

The standard is organized in accordance with FAA-STD-068.

FAA-STD-019F Content Arrangement

FOREWORD Normative Process Information

1 SCOPE

This chapter contains:

a. Scope Statement

b. Applicability Statement for mandatory compliance with requirements

c. Procedure for Tailoring of Mandatory Requirements

2 APPLICABLE

DOCUMENTS

This chapter includes technical documents used in this standard.

3 DEFINITIONS

This chapter contains definitions essential to the understanding and application of this standard. It is not intended to include commonly defined general or technical terms from building codes or industry standards.

4 GENERAL

REQUIREMENTS

This chapter addresses the general grounding system requirements commonly included in building codes and industry standards, and covers the general common requirements and standard practice for the overall design, installation, construction, and evaluation for FAA installations.

The general requirements of industry codes and standards are often too general for many FAA applications. This chapter is organized to define and build upon the requirements of general industry standards and building codes as they relate to FAA applications.

This chapter includes the following parts:

a. Bonding Requirements

b. Lightning Protection System Requirements

c. Earth Electrode System Requirements

d. National Electrical Code Power Distribution System

Grounding Compliance

e. Surge Protective Device Requirements

f. Grounding and Bonding Requirements for NAS Electronic

Equipment Areas

g. Shielding Requirements

h. Electrostatic Discharge Requirements

FAA-STD-019F Content Arrangement (continued)

5 DETAILED

REQUIREMENTS

This chapter describes detailed performance requirements, which are specific to FAA facility applications, organized by facility special conditions and equipment as follows:

a. Airport Traffic Control Tower Facilities

b. Lightning Protection System – Special Conditions

c. Facility Transient Protection – Special Conditions

d. Single Point Ground System (SPG) – Special Conditions

e. NAS Electronic Equipment – Interface and Procurement

Requirements

f. Surge Protective Device (SPD) – Procurement Requirements

g. Electrostatic Discharge Equipment – Interface and

Specification Requirements

h. Electromagnetic Compatibility Requirements

6 NOTES

This chapter includes:

a. Acronyms and Abbreviations

b. Guidelines and References Notes

c. Version Cross-Reference

d. Bibliography

Document conventions:

Designations indicated with brackets, e.g., " [A1] " preceding a section or paragraph title denote that explanatory material is provided in section 6.2.

Designations indicated with brackets, e.g., " [B1] " preceding a section or paragraph title indicates that bibliography reference material is provided in section 6.4.

2 APPLICABLE DOCUMENTS

2.1 General

Documents listed in this chapter are government and non-government reference documents that form a part of this standard and are applicable to the extent specified herein. While every effort has been made to ensure the completeness of this list, document users are cautioned that they shall meet all specified requirements of documents cited in Chapters 3, 4, and 5 of this standard, and national safety standards, whether or not they are listed.

a. In the event of a conflict between the text of this standard and the references cited herein, the text of this standard takes precedence. Nothing in this standard shall supersede applicable laws and regulations unless a specific exemption has been obtained.

b. Bibliography and reference source material is included in Chapter 0.

2.2 Government Documents

Due to periodic updating of government documents, the Contracting Officer and/or the Implementation Engineer shall specify the current version for project design or at contract award.

2.2.1 FAA Specifications

FAA-C-1217 Electrical Work, Interior FAA-G-2100 Electronic Equipment, General Requirements FAA-STD-012 Paint Systems for Equipment

2.2.2 FAA Orders and Handbooks

FAA-HDBK-010 Recommended Practices and Procedures for Lightning and Surge Protection, Grounding, Bonding, and Shielding Implementation

FAA-HDBK-011 Fundamental Considerations of Lightning Protection and Surge Protection, Grounding, Bonding, and Shielding

Copies of FAA specifications, standards, orders, and other applicable documents may be obtained from the Contracting Officer issuing the invitation-for-bid or request-for-proposal.

Requests for this material should identify the material desired, for example, the specifications, standards, amendments, drawing numbers and dates. Requests should cite the use for the material, invitation-for-bid, request-for-proposal, the contract number, or other intended use.

2.2.3 Military Documents

MIL-HDBK-232 Revision A Red/Black Engineering-Installation Guidelines

MIL-HDBK-237 Electromagnetic Compatibility Management Guide for Platforms, Systems and Equipment

DOD/MIL-HDBK-263 Electrostatic Discharge Control Handbook

DOD-STD-1686

Electrostatic Discharge Control Program for Protection of Electrical and Electronic Parts, Assemblies and Equipment (Excluding Electrically Initiated Explosive Devices)

MIL-HDBK-419 Grounding, Bonding, and Shielding for Electronic Equipment and Facilities

MIL-PRF-87893 Performance Specification, Workstation, Electrostatic Discharge Control

MIL-W-87893 Military Specification Workstation, Electrostatic Discharge (ESD) Control

MIL-STD-461 The Control of Electromagnetic Interference Emissions and Susceptibility

MIL-STD-889 Dissimilar Metals

MIL-STD-1686

Electrostatic Discharge Control Program for Protection of Electrical and Electronic Parts, Assemblies, and Equipment (Excluding Electrically Initiated Explosive Devices)

NACSIM 5203 Guidelines for Facility Design and Red/Black Installation (Confidential Document)

Single copies of Military specifications, standards, and handbooks are available by mail or telephone from Document Automation and Production Service Customer Service, Standardization Documents Order Desk, 700 Robbins Avenue, Building 4D, Philadelphia, PA 19111-5094. http://quicksearch.dla.mil/

Not more than five items may be ordered on a single request and all requests must contain the document number. Only the latest revisions (complete with latest amendments) are available.

Slash sheets must be individually requested. The Invitation for Bid or Contract Number should be cited where applicable.

2.3 Non-Government Documents

Due to periodic updating of non-government documents, the Contracting Officer and/or the Implementation Engineer must specify the current version for project design or at contract award unless a specific version is identified in this standard. These documents form a part of this standard and are applicable to the extent specified herein. While this standard may exceed the requirements of the following documents, building codes and industry standards always shall be followed as a minimum.

2.3.1 Electronic Industries Alliance (EIA)

JEDEC Standard

JESD625

Requirements for Handling Electrostatic-Discharge-Sensitive (ESDS) Devices

Copies of EIA Standards are available from JEDEC Solid State Technology Association, Mailing Address:

3103 North 10th Street, Suite 240-S, Arlington, VA 22201-2107. https://www.jedec.org/

2.3.2 National Fire Protection Association (NFPA)

NFPA 70 National Electrical Code (NEC) NFPA 77 Recommended Practice on Static Electricity NFPA 780 Standard for the Installation of Lightning Protection Systems Copies of NFPA documents are available from the National Fire Protection Association, One Batterymarch Park, Quincy, MA 02269. www.nfpa.org

2.3.3 Underwriters Laboratories (UL)

UL 96 Lightning Protection Components UL 96A Installation Requirements for Lightning Protection Systems UL 779 (ANSI-A148.1) Electrically Conductive Floorings UL 1449 Standard for Surge Protective Devices Copies of UL documents are available from Global Engineering Documents, 1500 Inverness Way, East Englewood, CO 80112. Telephone 303-397-7945, 800-854-7179. www.ul.com

2.3.4 Institute of Electrical and Electronic Engineers (IEEE)

ANSI/IEEE C62.41.2 Recommended Practice on Characterization of Surges in Low- Voltage (1000 V and Less) AC Power Circuits

ANSI/IEEE C62.45 Recommended Practice on Surge Testing for Equipment Connected to Low-Voltage (1000 V and Less) AC Power Circuits

ANSI/IEEE 1100 Recommended Practice for Powering and Grounding Sensitive Electronic Equipment (Emerald Book)

Copies of IEEE documents are available from Institute of Electrical and Electronic Engineers, 445 Hoes Lane, P.O. Box 1331, Piscataway, NJ 08855-9916. www.ieee.org

2.3.5 Electrostatic Discharge (ESD) Association Documents

ESD ADV1.0 Electrostatic Discharge Terminology - Glossary ESD ADV53.1 ESD Protective Workstations ESD S4.1 Worksurfaces Resistance Measurements ANSI/ESD S8.1 Symbols - ESD Awareness

ANSI/ESD S20.20

Development of an Electrostatic Discharge Control Program for Protection of Electrical and Electronic Parts, Assemblies and Equipment

ANSI/ESD STM 7.1 Floor Materials - Resistive Characterization of Materials

ANSI/ESD STM 11.11 Surface Resistance Measurement of Static Dissipative Planar Materials

ANSI/ESD STM 12.1 Seating - Resistive Measurement

ESD TR20.20

Handbook for the Development of an Electrostatic Discharge Control Program for the Protection of Electronic Parts, Assemblies and Equipment

ANSI/ESDA/JEDECD JS-

ESDA/JEDEC Joint Standard for Electrostatic Discharge Sensitivity Testing - Human Body Model (HBM) - Component Level

Copies of ESD Association documents are available from the EOS/ESD Association, Inc. 7900 Turin Road, Building 3, Rome, NY 13440-2069. Telephone 315-339-6937. www.esda.org

2.3.6 Telecommunication Industry Association (TIA) Documents

TIA-222 Structural Standard for Antenna Supporting Structures and Antennas Copies of TIA documents are available from the Telecommunications Industry Association, 1320 North Courthouse Road, Suite 200, Arlington, VA 22201. Telephone 703-907-7700.

www.tiaonline.org/standards/

3 DEFINITIONS

A Access Well A covered opening in the earth using concrete or other cementitious material to provide access to an EES connection.

Air terminal A strike termination device that acts as a receptor for attachment of flashes to the lightning protection system.

Armored Cable Power, signal, control, or data cable having an overall armor or covering constructed of ferrous (steel) material that provides both structural protection and electromagnetic shielding for direct buried cables.

Arrester Components, devices, and circuits used to attenuate, suppress, limit, or divert adverse electrical surge and transient energy. The terms arrester, suppressor, and protector are used interchangeably, except the term “arrester” is used herein for components, devices, and circuits installed on the primary side of FAA-owned distribution transformers.

B Bond The electrical connection between two metallic surfaces used to provide a low-resistance path between them.

Bond, Direct An electrical connection utilizing continuous metal-to-metal contact between the members being joined.

Bond, Indirect An electrical connection employing an intermediate electrical conductor between the bonded members.

Bonding The joining of metallic parts to form an electrically conductive path to ensure electrical continuity and the capacity to conduct current imposed between the metallic parts.

Bonding Jumper A conductor installed to ensure electrical conductivity between metal parts required to be electrically connected.

Bonding Jumper, for NEC Compliance

See NEC definitions for power distribution wiring terms such as "Equipment," "Main," or "System" bonding jumper.

Branch Circuit The circuit conductors between the final overcurrent protective device and the load.

Building “Structural” Steel

The main building structural steel members consisting of columns and beams or girders. Concrete-encased reinforcing steel rebars may be considered structural steel, depending on location.

Bulkhead Ground Plate

A metallic plate located where conduits, conductors, cables, waveguides, etc, enter the facility from the exterior. The bulkhead plate provides a central point for the grounding of these services to minimize external transients from entering the facility or structure.

Bushing An insulated device that allows an electrical conductor to pass safely through a grounded conducting barrier such as the case of a panel, transformer, etc. The primary purpose is to prevent chafing of the conductors.

Bushing, Grounding or Bonding

An insulated device that allows for a grounding method at the end of the conduit. Also known as grounding-type bonding bushing or bonding bushing.

C Cabinet An enclosure designed either for surface mounting or flush mounting that is provided with a frame, mat, or trim in which a swinging door or doors are, or can be, supported.

Cable A fabricated assembly of one or more conductors in a single outer insulation. Types include axial, armored, and shielded.

Cable, AC A fabricated assembly of insulated conductors in a flexible metallic enclosure. Type armored-cable (AC) cable is not the same as DEB cable.

Cable, Axial Cable where all conductors are oriented on a single axis, such as coaxial, biaxial, and tri-axial cables.

Cable, Direct Buried Cable with construction suitable for use in direct buried, underground installations without any form of conduit. Type direct buried cable is not the same as DEB cable.

Cable, Direct Earth Burial (DEB)

Cable with a ferrous shield designed to provide both physical and electromagnetic protection to the conductors.

Cable, MC Metal-Clad Cable, Type MC. A factory assembly of one or more insulated circuit conductors with or without optical fiber members enclosed in an armor of interlocking metal tape, or a smooth or corrugated metallic sheath. See NEC.

Note: For the purpose of this standard, MC cable is only permitted when installed in accordance with FAA-C-1217.

Cable, Shielded Cable with a metalized or braid shield to improve resistance to electromagnetic interference (EMI).

Case A protective housing for a unit or piece of electrical or electronic equipment.

Chassis The metal structure that supports the electrical or electronic components that make up the unit or system.

Conductor, Bare An electrical conductor that has no covering or electrical insulation.

Conductor, Insulated

An electrical conductor encased within material of composition and thickness recognized by the NEC as electrical insulation.

Conductor, Lightning Bonding (Secondary)

An electrical conductor used to bond a metal object, within the zone of protection and subject to currents induced by lightning strikes, to the lightning protection system.

Conductor, Lightning Down

The down conductor serves as the path to the EES from the roof system of air terminals and roof conductors or from an overhead ground wire.

Conductor, Lightning Main

Conductors intended to carry lightning currents between air terminals and the EES. These can be conductors interconnecting air terminals on the roof, conductors connecting a metal object on or above the roof level that is subject to a direct lightning strike to the lightning protection system, or the down conductor.

Conductor, Lightning Roof

Roof conductors interconnecting all air terminals to form a two-way path to the EES from the base of each air terminal.

E Earth Electrode System (EES)

A network of electrically interconnected grounding systems such as ground rods, ground plates, ground mats, incidental electrodes including metallic piping and tanks, or ground grids installed below grade to establish a low resistance contact with earth.

Electromagnetic Interference (EMI)

Any emitted, radiated, conducted, or induced voltage that degrades, obstructs, or interrupts the required performance of electronic equipment.

Electronic Multipoint Ground System (MPG)

An electrically continuous network consisting of interconnected ground plates, equipment racks, cabinets, conduit junction boxes, raceways, duct work, pipes, copper grid system, building framing steel, and other non-current-carrying metal elements. It includes conductors, jumpers, and straps that connect individual electronic equipment components to the signal reference structure (SRS).

Electronic Single Point Ground System (SPG)

A discreet signal reference network that provides a single point of reference in the facility for electronic equipment which require single point grounding. It consists of conductors, plates, and equipment terminals, all of which are isolated from any other grounding system except at the main ground plate.

Enclosed Cable Tray A cable tray with steel/aluminum sides and bottom with a steel/aluminum cover or lid.

Equipment A general term including materials such as fittings, devices, appliances, fixtures, apparatus, and machines, used in conjunction with an electrical installation.

Equipment Areas Areas that house electronic equipment used to support NAS operations, such as electronic equipment rooms, telephone company (TELCO) rooms, Very High Frequency Omni Directional Range (VORs), and Radars.

Equipment Grounding Conductor (EGC)

The conductive path installed to connect normally non-current-carrying metal parts of equipment together and to the system grounded conductor or to the grounding electrode conductor, or both. For FAA purposes, the EGC is to be green-insulated, solid or stranded, copper wire.

F Ferrous Conduit Conduits composed of or containing iron, which are used to provide magnetic shielding, such as Rigid Galvanized Steel Conduit (RGS) or thick walled threaded conduit (NEC Rigid Metal Conduit-RMC).

Note: For the purpose of this standard, Electrical Metallic Tubing (EMT), Intermediate Metal Conduit (IMC), and conduits made from silicon bronze and stainless steel are not adequate for magnetic shielding protection.

Fitting, High Compression

See “Pressure Connector Terminations.”

G Ground A conducting connection, whether intentional or accidental, between an electrical circuit or equipment and the earth, or to a conducting body that serves in place of the earth.

Ground Dissipation Plate Design

Ground plate, refer to Figure 6.

Grounded Connected to earth via a path of sufficiently low impedance and having sufficient current carrying capacity, such that fault current cannot build up voltage potentials that are hazardous to personnel.

Grounded Conductor

A system or circuit conductor that is intentionally grounded at the SDM or at the source of a separately derived system. This grounded conductor is the neutral conductor for the power system.

Grounding Conductor

A conductor used to connect equipment or the grounded circuit of a wiring system to a grounding electrode or electrodes.

Grounding Electrode

Copper rod, plate, or wire embedded in the ground for the specific purpose of dissipating electric energy to the earth. Also referred to as the Grounding Electrode System.

Grounding Electrode Conductor (GEC)

A conductor used to connect the system grounded conductor or the equipment to a grounding electrode or to a point on the grounding electrode system.

H High Frequency All electrical signals at frequencies greater than 100 kHz, and pulse and digital signals with rise and fall times of less than 10 μs.

High Transient Ground Plate

Entry or termination ground plate for connection of axial cable surge protection equipment and termination of cable shields, waveguides, conduits, and cable jackets. See Bulkhead Ground Plate.

Horizontal Transitions

Architectural term used to describe horizontal elements in a vertical structure, such as floor levels and stair landings.

Hydraulically Crimped Termination

Conductor termination using a hydraulic crimping tool that applies a 12-ton minimum compression force, using concentrically or circumferentially matching dies to form the connection.

I Inaccessible Location

A condition where gaining access to a system or part thereof requires significant effort, cost, or risk to personnel safety. Examples of such locations include below grade, behind walls and obstructions, or enclosed or concealed spaces that impede visual inspection.

L Landline Any conductor, line, or cable installed externally above or below grade to interconnect electronic equipment in different facility structures or to interconnect externally mounted electronic equipment.

Low Frequency Voltages and currents, whether signal, control, or power, up to and including 100 kHz. Pulse and digital signals with rise and fall times of 10 μs or greater are considered to be low-frequency signals.

M Main Service Disconnect

A switch, fused switch, or circuit breaker that disconnects the main ac power service, generally utility power source, from a facility, located at the service disconnecting means (SDM).

Mullion A slender vertical member that forms a division between units of a window.

O Office of Primary Responsibility

(OPR)

The authority assigned to maintain and interpret this standard.

Operational Areas Areas used to provide NAS support such as Instrument Flight Rules (IFR) rooms, Air Route Traffic Control Center (ARTCC) control rooms, ATCT tower cabs, operations control centers, and TRACON control rooms.

P Pressure Connector Terminations

Conductor termination using a mechanically bolted pressure connection.

R Rack A metal frame in which one or more electronic equipment units are mounted.

Rigid Metal Conduit (RMC), Rigid Galvanized Steel Conduit (RGS)

A threaded raceway of circular cross-section designed for the physical protection, routing, and shielding of conductors and cables.

S Service Disconnecting Means (SDM)

Refer to the NEC definition for Service Point location.

Shield A housing, shield, or cover that substantially reduces the coupling of electric and magnetic fields into or out of circuits or prevents accidental contact of objects or persons with parts or components operating at hazardous voltage levels.

Signal Any electromagnetic transmission of information or control function. A signal can be analog, digital data, or a control function such as a relay closure.

Signal Ground Pad A pad or post for connecting the terminal of an incoming ground wire to the rack equipment.

Signal Reference Structure (SRS) System

The conductive terminal, wire, bus, plane, or network that serves as the relative zero potential for all associated electronic signals. Signal Reference Structures are required at locations or areas containing NAS electronic equipment.

Structure Any fixed or transportable building, shelter, tower, mast, or other load-bearing system that is intended to house electrical or electronic equipment or otherwise support or function as an integral element of the air traffic control system.

Surface Resistivity Surface Resistivity can be described as follows: For electric current flowing across a surface, the ratio of DC voltage drop per unit length to the surface current per unit width. In effect, the surface resistivity is the resistance between two opposite sides of a square and is independent of the size of the square or its dimensional units. Surface resistivity is expressed in ohms/square. See ESD ADV1.0 Glossary of Terms.

Surge A short-term disturbance characterized by a sharp, brief discontinuity of a waveform. May be of either polarity and may be additive to, or subtractive from, the normal waveform.

Surge Protective Device (SPD)

A device intended to limit surge voltages on equipment by diverting or limiting surge current and is capable of repeating these functions as specified. SPDs are also commonly referred to as Transient Voltage Surge Suppressors (TVSS) or secondary surge arresters.

Susceptibility Level The transient level on signal, control, or data lines that causes damage, degradation, or upset to electronic circuitry connected to the line.

T Transient See Surge.

Transient Suppressor

Components, devices, or circuits designed for the purpose of attenuating, absorbing, and suppressing conducted transient and surge energy to protect facility equipment.

Z Zone of Protection The space adjacent to a lightning protection system that has a reduced probability of receiving a direct lightning strike.

4 GENERAL REQUIREMENTS

4.1 Introduction

This chapter covers the common requirements and standard practice for the overall design, installation, construction, and evaluation of the following grounding systems in FAA facilities:

a. Bonding Requirements

b. Lightning Protection System Requirements

c. Earth Electrode System (EES) Requirements

d. National Electrical Code (NEC) Power Distribution System Grounding Compliance

e. Surge Protective Device (SPD) Requirements

f. Grounding and Bonding Requirements for NAS Electronic Equipment Areas

g. Shielding Requirements

h. Electrostatic Discharge (ESD) Requirements

4.2 Bonding Requirements

The method of bonding, for the purpose of achieving electrical continuity, shall be in accordance with 4.2.1 through 4.2.5.

4.2.1 General

This section covers the following topics:

a. Dissimilar Metals Compatibility Requirements

b. Methods of Bonding

c. Bonding Connection Installation Requirements

d. Hardware for Bonding Jumpers and Straps

4.2.1.1 [A1] Resistance of Bonds Unless otherwise specified in this standard, bonds shall have a maximum direct current (dc) resistance of 1 mΩ when measured between the bonded components with a four-terminal milliohmmeter.

4.2.2 Dissimilar Metals

Bonding connections and associated fastener hardware for grounding system conductors shall comply with Table 1.

Table 1. Mechanical Bonds Between Dissimilar Metals Note: This table is for information purposes only. Practice will depend on the application and the availability of UL listed material.

C op pe r, so lid o r p la te

Br as s an d br on ze

St ai nl es s St ee l

Ti n-pl at e;

ti n-le ad s ol de r

Al um in um

, w ro ug ht a llo ys o f t he

Se rie s

Iro n, w ro ug ht

, g ra y or m al le ab le , p la in ca rb on a nd lo w a llo y st ee ls

Al um in um

, w ro ug ht a llo ys o th er th an

Se rie s al um in um

, c as t a llo ys o f t he s ilic on ty pe

Al um in um

, c as t a llo ys o th er th an s ilic on ty pe

, p la te d an d ch ro m at e

G al va ni ze d st ee l

Zi nc

, w ro ug ht

; z in c-ba se d ie -c as tin g al lo ys zi nc p la te d

••• ••• •• • • • No No No No

••• ••• •• •• • • • No No No

•• •• ••• ••• ••• •• • • No No

• •• ••• ••• ••• •• •• • No No

No • • •• ••• ••• ••• ••• • •

No No • • •• ••• ••• ••• •• •

No No No No • • • •• ••• •••

No No No No • • • • ••• •••

No

Aluminum, w rought alloys of the 2000 Series

METAL

Copper, solid or plate

Brass and bronze

Stainless Steel

Tin-plate; tin-lead solder

Suitable for all indoor environment.

Suitable for all environments.

LEGEND: Four Basic Categories of Possible Metal Interfaces

Iron, w rought, gray or malleable, plain carbon and low alloy steels

Aluminum, w rought alloys other than 2000 Series aluminum, cast alloys of the silicon type

Aluminum, cast alloys other than silicon type, plated and chromate

Galvanized steel

Zinc, w rought; zinc-based die-casting alloys; zinc plated

Not suitable. This interface is highly likely to result in significant corrosion.

Suitable for indoor environments where temperature and humidity are controlled (non-condensing environment).

4.2.3 Methods of Bonding

Direct bonding techniques include:

a. Exothermic Welds. Exothermic welds are permitted for any type of bond connection specified herein.

b. Hydraulically Crimped Terminations. Crimped terminations are permitted as an alternative technique to facilitate installation of connections in permanently concealed or inaccessible locations.

c. Welded Assemblies. Metal fabrication assembly process constructed by welding the joints between the individual components.

d. Mechanical Connections. Electrical bond connections constructed with bolted assemblies.

e. Brazing and Soldering. Metal-joining process formed by brazing or soldering a filler alloy metal is not permitted for bond connections.

f. Silver Soldering - Only Applicable for NAS Electronic Equipment. To improve conductivity, silver soft soldering material may be applied for the bonding of enclosure shielding joints already secured with mechanical fasteners. Mechanical fasteners shall be attached prior to application of solder to prevent cold solder joints. Soft soldering techniques are not permitted as a method for providing mechanical restraint.

4.2.3.1 Exothermic Welds

Exothermic welded connections shall be provided for the following applications:

a. Permanent Bonding. Permanent bonding of copper conductors to metal assemblies or building steel.

b. Underground or Buried Locations.

c. Exposed Exterior Locations. Any exposed location where an exothermic weld connection is possible.

d. Permanently Concealed Locations. Locations where the connection will be permanently concealed after completion of fabrication or building construction process.

e. Inaccessible Locations. Locations rendered inaccessible due to a building feature or other physical constraint that restricts routine access necessary to perform maintenance and visual inspection.

Safety equipment, such as welding trays and welding blankets, shall be used for all exothermic welding activities. Refer to 29 CFR 1910.252 for applicable requirements related to exothermic weld implementation activities.

Exception. Where exothermic welds are not possible due to dissimilar materials, incompatible shapes, voiding of a manufactured finish warranty, or in hazardous locations, such as near fuel tanks or other combustible material, provide UL listed hydraulically crimped or mechanical connections.

4.2.3.1.1 Exothermic Welds – Installation within Existing Facilities The following measures shall be taken in the installation of exothermic welds within existing facilities:

a. Where combustion from the use of a standard exothermic weld process would result in problems within the facility, a smokeless type exothermic weld process shall be provided.

b. After completing the welding process, to prevent corrosion, remove or neutralize residual fluxes between components.

4.2.3.2 Hydraulically Crimped Terminations

A UL 467 and UL 96 listed irreversible compression type bonding connection is permitted for use within concealed and inaccessible locations, and in areas where exothermic weld connections are deemed hazardous.

a. Bonding Conductors. Bonding conductors shall be wire size 6 AWG or larger.

b. Hydraulic Compression Tool System. Hydraulic compression tool system shall be capable of producing a 12-ton minimum force applied with a tool using matching dies.

4.2.3.3 Welded Assemblies

Individual components of a welded assembly shall not require additional bonds between components if the dc resistance between individual components is less than 1 mΩ.

4.2.3.4 Mechanical Bolted Bond Connections

Mechanical bolted bond connections shall be prepared and completed in accordance with the installation conditions and requirements provided herein.

4.2.3.4.1 [A2] Coupling of Dissimilar Metals Compression bonding with bolts and clamps shall comply with Table 1. When dissimilar base metals form couples that are not permitted per Table 1, the metals shall be coated, plated, or otherwise protected with a conductive finish.

4.2.3.4.2 Bolted Connections

Bonding bolts shall be used primarily as mechanical fasteners to hold electrical bonding components in place. Tighten bolts sufficiently to achieve adequate contact pressures for effective bonding, but do not overtighten them to the extent that deformation of bond members occurs. To prevent loosening of the connection, provide disc springs for connections using bolts 1/4-in. diameter and greater.

a. Torque Requirements. Bolted connections 1/4-in. diameter and greater shall conform to the torque requirements in Table 2.

b. Bolts, Nuts and Washers. Bolted connections in corrosive, damp, or wet locations, 1/4-

in. diameter and greater, shall utilize stainless steel type 18-8 bolts, nuts, and load distribution washers. All other locations shall use corrosion-inhibited SAE Standard J429 Grade 5 nuts and bolts. Load distribution washers shall comply with ANSI B18.22.1 for stainless steel washers, Wide Series, Type B.

c. Assembly. Bolted connections 1/4-in. diameter and greater shall be assembled in the order shown in Figure 1. Additional load distribution washers, if used, shall be positioned directly beneath the bolt head. Disc springs shall be between the nut and the load distribution washer. Washers shall not be placed between bonded members. Load distribution washers shall be Wide Series, Type B.

d. Termination Lugs. Provide 2-hole termination lugs for connections to ground plates.

Provide 2-hole termination lug connections to equipment metal members for conductors size 6 AWG and larger. If the equipment metal members do not allow modification for installation of 2-hole lug terminations, then 1-hole termination lugs are permitted.

4.2.3.4.2.1 Sheet Metal Screws

Sheet metal screws shall not be used to provide an electrical bond.

4.2.3.4.2.2 Self-drilling and Self-tapping Screw Fasteners

Self-drilling and self-tapping metal screws are permitted to make a physical connection between metal back panels within equipment cabinet/enclosures when access to the opposite side of the bond is not available using other bonding methods.

4.2.3.4.3 Riveting

Rivets shall be employed solely as mechanical fasteners to hold multiple smooth, clean metal surfaces together or to provide a mechanical load-bearing capability to a soldered bond.

Table 2. Connection Torque Requirements for Bolted Bonds

Bolt Specification for Stainless Steel 301 Type SS 18-8

Bolt diam.

(in.)

Threads per inch

Torque (ft-lbs)

SS 18-8

Bolt Clamp Load

(lbs.)

Flat Load (lbs.)

Washers Required

(see note 2)

Solon Part Number

(see note 1) 1/4 20 6 1,510 600 3 4-L-42-301 5/16 18 11 2,120 1,000 3 5-L-52-301 3/8 16 19 3,150 2,100 2 6-M-80-301 7/16 14 31 4,300 N/A N/A N/A 1/2 13 43 5,170 3,300 2 8-L-90-301 9/16 12 56 6,070 2,800 3 9-L-89-301 5/8 11 92 8,880 5,500 2 10-20-125-301

3/4 10 127 10,200 13,800 1 12-EH-168-177

7/8 9 194 13,310 14,400 1 14-H-168-177 1 8 286 17,200 14,200 2 16-H-187-177

Bolt Specification for SAE J429 Type Grade 5

Bolt diam.

(in.)

Threads per inch

Torque (ft-lbs)

Grade 5

Bolt Clamp Load

(lbs.)

Flat Load (lbs.)

Washers Required

(see note 2)

Rolex-Fastenal Part Number

(see note 1) 1/4 20 10 2,500 1,390 2 0124030 5/16 18 21 4,000 5,345 1 0124033 3/8 16 34 5,500 8,000 1 0124035 7/16 14 55 7,500 N/A N/A N/A 1/2 13 83 10,000 9,900 2 0124037 9/16 12 117 12,500 12,000 2 0124039 5/8 11 167 16,000 13,000 2 0124041 3/4 10 288 23,000 31,000 1 0124043 7/8 9 452 31,000 40,276 1 0124044 1 8 567 40,000 46,000 1 0124046

Notes:

1. Other manufacturers of disc spring washers of equal or better performance are permissible. Use bolt assembly manufacturer’s recommended torque values.

2. The sum of the individual disc washer flat load ratings shall exceed the listed bolt clamp load.

The number of washers required is calculated by the following formula:

B Bolt Clamp Load < W Number of Washers x F Washer Flat Load For example, a 1/4-in. stainless steel bolted connection requires minimum 1,510 lbs clamp load, therefore, 3 disc washers will be needed.

Figure 1. Order of Assembly for Bolted Connections

4.2.4 Bonding Connections – Installation Requirements

Bonding connections shall be prepared and completed in accordance with the installation conditions and requirements provided herein.

4.2.4.1 Surface Preparation

Bonding surfaces shall be cleaned thoroughly and free of dirt, dust, grease, oxides, nonconductive films, and foreign material. Paint and other coatings at the location shall be removed to expose the base metal.

a. Surface Area To Be Cleaned. Clean mating surfaces at least 1/4-in. beyond each side of the smaller bonded area.

b. Clad Metals. Clean clad metal to a bright, shiny, smooth surface without penetrating the cladding. Wipe the cleaned area with solvent and allow the surface to air dry before completing the bond.

c. Aluminum Alloys. To create a bright finish after cleaning, apply a conductive coating with paint or resin finish to aluminum mating surfaces.

4.2.4.2 Completion of Bonding Connection

Clean surfaces with a solvent suitable for electrical work immediately prior to assembly. Mating surfaces shall be joined within 2 hours after cleaning if an intentional protective coating has been removed from the metal surface. If delays beyond 2 hours are necessary in corrosive environments, then the cleaned surfaces shall be protected with an appropriate coating that shall be removed prior to completion of the bond connection.

a. Refinishing of Bond. Areas around the bond connection shall be restored to match the original finish, unless not feasible.

b. Surface Plating or Treatments. Surface plating or treatments may be applied to the connection to improve abrasion resistance and corrosion protection, provided the treatment material enhances bond conductivity. Silver and other easily tarnished metals shall not be used to plate bonded surfaces, except where use of other metals may result in an unacceptable increase in surface contact resistance. In such cases, protect plating material by sealing exposed surfaces of the completed connection from the atmosphere.

4.2.4.3 Sealing and Finish Treatments for Bonding Connections All bonds shall be protected against weather, corrosive atmospheres, vibration, and mechanical damage. Under dry conditions, apply a compatible corrosion preventive or sealant within 24 hours of assembly of the bond materials.