Attachment 6 - AFI 32-1065.pdf

BY ORDER OF THE

SECRETARY OF THE AIR FORCE

AIR FORCE INSTRUCTION 32-1065

12 JANUARY 2015

Civil Engineering

GROUNDING SYSTEMS

COMPLIANCE WITH THIS PUBLICATION IS MANDATORY

ACCESSIBILITY: Publications and forms are available for downloading or ordering on the e-Publishing website at www.e-publishing.af.mil.

RELEASABILITY: There are no releasability restrictions on this publication.

OPR: AF/A4CX

Supersedes: AFI32-1065, 1 October 1998

Certified by: AF/A4CX

(Col Valerie L. Hasberry)

Pages: 49

This instruction implements AFPD 32-10, Installations and Facilities. It assigns maintenance responsibilities and requirements for electrical grounding systems on Air Force installations.

This includes systems for equipment grounding, lightning protection, and static protection. This instruction also implements the maintenance requirements of DoD 6055.09-M, Volume 2, Ammunition Explosives Safety Standards, Enclosure 4, Lightning Protection, February 2008, for potentially hazardous explosives facilities. This instruction applies to all personnel, to include

Air Force Reserve Command (AFRC) units and the Air National Guard (ANG). This publication may be supplemented at any level, but all direct Supplements must be routed to the Office of

Primary Responsibility (OPR) of this publication for coordination prior to certification approval.

The authorities to waive wing/unit level requirement in this publication are identified with a Tier

(“T-0, T-1, T-2, T-3”) number following the compliance statement. See AFI 33-360, Publications and Forms Management, for a description of the authorities associated with the Tier numbers. Sub mit requests for waivers through the chain of command to the appropriate Tier waiver approval authority, or alternately, to the Publication OPR for non-tiered compliance items. Refer recommended changes and questions about this publication to the OPR using the

AF Form 847, Recommendation for Change of Publication; route AF Forms 847 from the field through the appropriate functional chain of command. Ensure that all records created as a result of processes prescribed in this publication are maintained in accordance with (IAW) Air Force

Manual (AFMAN) 33-363, Management of Records, and disposed of IAW the Air Force

Records Information Management System (AFRIMS) Records Disposition Schedule (RDS).

The use of the name or mark of any specific manufacturer, commercial product, commodity, or service in this publication does not imply endorsement by the Air Force.

FA301024R0013

Attachment 6 http://www.e-publishing.af.mil./

2 AFI32-1065 12 JANUARY 2015

SUMMARY OF CHANGES

This document has been substantially revised and must be completely reviewed. Major changes include the addition of Tier wavier authority requirements, updated office symbols, and updated references.

AFI32-1065 12 JANUARY 2015 3

Section A—Maintenance Policy 3

1. Responsibilities

Table 1. Scheduled Maintenance for Grounding Systems

2. Codes and Specifications

3. Required Maintenance

4. Recordkeeping and Review

5. Forms

6. Personnel Qualifications

7. Developing Procedures

Section B—Grounding Resistance and Continuity Tests and Visual Inspections 17

8. Testing Requirements

9. Visual Inspections of Lightning Protection Systems

10. Visual Inspection of Facility Grounds

Section C—Grounding and Lightning Protection Requirements 18

11. Introduction

12. Testing and Inspecting Static and Lightning Protection Systems and Grounding: 19

Figure 1. Example Sketch of Test Points (Typical)

13. Static Protection

14. Lightning Protection Systems

15. Surge Protection

Attachment 1—GLOSSARY OF REFERENCES AND SUPPORTING INFORMATION 26

Attachment 2—BASIC REQUIREMENTS FOR GROUNDING SYSTEMS (T-0) 30

Attachment 3—(T-0) BASIC BONDING REQUIREMENTS 34

Attachment 4—LIGHTNING PROTECTION SYSTEMS (T-0) 42

Attachment 5—MAINTENANCE GUIDELINES FOR EXPLOSIVES FACILITIES (T-0) 44

Attachment 6—TESTING REQUIREMENTS (T-0) 45

Section A—Maintenance Policy

1. Responsibilities.

4 AFI32-1065 12 JANUARY 2015

1.1. Air Force Director of Civil Engineers (AF/A4C). Establish policy for Grounding

Systems.

1.2. Air Force Civil Engineer Center (AFCEC).

1.2.1. Establishes standards and criteria for design, maintenance, repair, and management of grounding and bonding systems IAW mandatory requirements of UFC 3-

520-01 Interior Electrical Systems, UFC 3-550-01, Exterior Electrical Power

Distribution, UFC 3-575-01 Lightning and Static Electricity Protection Systems, and

UFC 3-580-01 Telecommunications Building Cabling Systems Planning and Design. (T-

0)

1.2.2. Reviews emerging and evolving technologies and evaluates for applicability to the

Air Force. (T-1)

1.2.3. Evaluates grounding and bonding training conducted internal to the Air Force, conducted by the Defense Ammunitions Center (DAC), and conducted by the private sector. (T-1)

1.2.4. Assists major commands (MAJCOMs) and Direct Reporting Units (DRUs) and installations with inspection of grounding and bonding systems and with troubleshooting electrical issues which are suspected to stem from grounding and bonding issues and discrepancies.. (T-1)

1.2.5. Assists Air Force Safety Center and Inspector General personnel with determination of equivalency of grounding and bonding protection systems. (T-1)

1.3. The Base Civil Engineer (BCE).

1.3.1. Maintain lightning and grounding systems specifically identified in Table 1 according to the procedures in this instruction. (T-0)

1.3.2. Make sure that user organizations identified in Table 1 are aware of their maintenance responsibilities. (T-1)

1.3.3. Train users to perform their responsibilities to inspect and maintain lightning and grounding systems as identified in Table 1 when requested. On Installations where the electrical utility system is owned by a private entity, consult with the private/system owner. (T-1)

AFI32-1065 12 JANUARY 2015 5

Table 1. Scheduled Maintenance for Grounding Systems.

Facility or

System

Action

Required

Frequency of Action

Responsible

Organization Reference Comments

1. Exterior

Electrical

Distribution

a. Visual inspection of electrical distribution equipment fencing, pole grounds, pad mounted equipment grounds and neutrals.

5 years Base Civil

Engineer

AFJMAN

32-1082, Facilities

Engineering electrical

Exterior

Facilities

UFC 3-550-

01, Exterior

Electrical

Power

Distribution

UFC 3-501-

01, Electrical

Engineering

1. Any and all

Inspections should follow

NETA MTS

guidance

2. It is not necessary to perform the

5-year inspection of the system in a single year;

however at the end of 5 years documentation must show that the entire system has been inspected.

3. If utility is privatized, this does not apply;

however safety and operational discrepancies and damage should be reported when observed.

b. Physical continuity of grounds for separately derived systems

2 years Base Civil

Engineer This AFI

Purpose is to ensure that ring currents are not established by the existence of grounds for multiple systems and equipment.

6 AFI32-1065 12 JANUARY 2015

2. Electrical

Substation

(if base owned or totally/partiall y maintained by the base)

a. Continuity check across gate opening

(1 ohm or less)

5 years Base Civil

Engineer

AFJMAN

32-1082;

NETA MTS

b. Ground resistance measurement of entrance gate (5 ohms or less)

3. Exterior

Lightning

Arresters and/or surge suppressive devices on

Primary

Distribution

Lines (even if privately owned).

Visual 5 years Base Civil

Engineer

AFJMAN

32-1082

Purpose is to ensure reliability to the AF mission.

Discrepancies should be reported, in writing, to the owner if other than AF.

4. General

a. Facility

Service

Entrance -visual inspection

When electrical work is performed at facility

Engineer

NFPA 70

(NEC), Art

250, NFPA 70

(NEC)B,

UFC 3-575-

01, Lightning and Static

Electricity

Protection

Systems

Tag or mark in a conspicuous place, to indicate visual inspection date and initials of inspector

AFI32-1065 12 JANUARY 2015 7

b. Verify bonding of other systems to facility grounds

Upon new installation, installation or upgrade of other systems requiring grounding, and prior to contract acceptance

Base Civil

Engineer

NFPA 70

(NEC)

Purpose is to ensure the integrity of the single point facility ground.

c. Visual inspection of lightning protection system

1-2 years, as determined by

MAJCOM

EE based on facility type

Base Civil

Engineer

This AFI

NFPA 780

UFC 3-575-

Purpose is to note mechanical damage, lightning damage or discrepancies caused by repair, renovation, or addition.

d. Facility ground resistance check (25 ohms or less)

5 years

This AFI

5. POL

Facilities

a. Resistance measurement on static grounds

(10,000 ohms or less)

Upon installation and when observed to be physically damaged

Base Civil

Engineer

UFC 3-460-

03, 21

January

2003, Maintenance of Petroleum

Systems

8 AFI32-1065 12 JANUARY 2015

b. Visual inspection and mechanical check of ground conductor connections

(pull test)

Quarterly, or before each use

Annually

User

BCE

UFC 3-460-

03, 21

January

2003, Maintenance of Petroleum

Systems, Para 10.3.20

c. Inspection of connection to grounding electrode

Annually BCE

UFC 3-460-

03, 21

January

2003, Maintenance of Petroleum

Systems, Para 10.3.20

d. Facility

Service -visual inspection

When electrical work is performed at facility

BCE

(NEC), Art

250, (NEC)B,

Tag or mark in a conspicuous place, to indicate visual inspection date and initials of inspector

6. Fuels Lab

a. Visual inspection and continuity validation of equipment grounds

Monthly User

AFI 91-203

para

36.5.4.2.2. &

36.5.4.2.3.

b. Visual inspection of facility grounds

Monthly User AFI 91-203

7. Aircraft

Parking Apron

Grounds and

Hangar Floor

Static

Grounds

Resistance measurement on static grounds

(10,000 ohms or less)

When installed or repaired

Base Civil

Engineer

UFC 3-575-

01, 1 Jul 12

AFI32-1065 12 JANUARY 2015 9

8. LOX

Storage

Resistance measurement on static ground

(10,000 ohms or less)

When installed, physically damaged, or repaired

Base Civil

Engineer This AFI

9. Rail Car

Off-loading

Spur

Visual inspection of rail bonding

Annually (If the rail car enters an explosive facility, test for continuity every two years)

Base Civil

Engineer This AFI

10.

Communicati ons (&

TEMPEST)

Facilities

Resistance measurement at service entrance (10 ohms or less is design objective. If

10 ohms cannot be obtained after compliant installation of a ground loop, a reading of 25 ohms or less is acceptable.)

Quarterly for first year after installation;

then every 21 months (see

Note for this item.)

Base Civil

Engineer

(NEC)

Communicatio ns facilities require tiered surge suppression – protection at the main distribution panel and any sub- panel serving sensitive communication s equipment, HVAC, and at communication s equipment.

Note: User has requested 21 months in order to comply with their references.

10 AFI32-1065 12 JANUARY 2015

11.

Communicati ons

Equipment

Checks involving in-house electronic equipment ground

Determined by user from

T.O. and equipment manufacturer

User

MIL-HDBK-

419A

Communicatio ns facilities require surge suppression devices (SPDs) on both the line and load sides of the main distribution panel, the line and load sides of any panel serving sensitive comm.

equipment, and at the communication s equipment itself.

Note: For sensitive communication s equipment inside non-comm facilities, SPDs are required on the line and load sides of the panel serving sensitive communication s equipment.

AFI32-1065 12 JANUARY 2015 11

12.

Hazardous

Explosives

Area

(Weapons)

a. Visual inspection of static bus bars, grounding conductors, and bonds

Before using equipment each day and every 6 months

Annually (for nuclear facilities)

AFMAN 91-

201, Para

5.13.3.2 and

5.23.4.2.3.3.

b. Resistance to ground for equipment bonding straps

(10,000 ohms or less)

Before each use User

AFMAN 91-

201, Para

5.13.1

c. Continuity across bonds, between bus bars, conductors, and bonding straps (less than 1 ohm)

3 months or according to specific item

T.O.

After system modification s

AFMAN 91-

201, 5.24.2.1

NFPA 780,

Ch 8 ground resistance check (25 ohms or less)

24 months Base Civil

NEC

5.13.1 e.

Conductive floor grounding check

Upon installation and when damage is noted.

Base Civil

Engineer

AFMAN 91-

201, Para

5.19.1

f. Visual inspection of

Surge

Suppressors

6 months and after a lightning strike annually

AFMAN 91-

201, Para

5.23.4.2.3.3.

12 AFI32-1065 12 JANUARY 2015

g. See nonhazardou s explosives requirements

12g, 13e, 13f, 13g, and

13h.

This Block is

Intentionally

Blank

This Block is

Intentionally

Blank

This Block is

Intentionally

Blank

13. Non-

Hazardous

Explosive

Area

(Weapons)

a. Visual inspection of static bus bar, conductor and bonds

Quarterly

Annually

AFMAN 91-

5.13.4

Intent of

“quarterly” is every 90 days, +/- 5 days.

b. Resistance to ground for equipment bonding straps

(10,000 ohms or less)

Before each use User

AFMAN 91-

201 Para

5.13

c. Continuity check from equipment to static bus bar

(1 ohm or less)

24 months User

AFMAN 91-

201 Para

5.13 ground resistance check (25 ohms or less)

24 months Base Civil

Engineer This AFI

e. Visual inspection of lightning protection system components

12 months Base Civil

Engineer This AFI

AFMAN 91-

201 refers to

AFI 32-1065

AFI32-1065 12 JANUARY 2015 13

f. Resistance measurement on lightning protection earth to ground system (25 ohms max)

24 months Base Civil

Engineer

AFMAN 91-

201, Para

5.24.2.2 ;

This AFI

AFMAN 91-

201 refers to

AFI 32-1065

g. Continuity validation on air terminals, bonds, and conductor connections

(1 ohm or less)

24 months Base Civil

Engineer

201; this AFI

h. Static bus bar continuity to ground (1 ohm or less)

24 months Base Civil

Engineer

201; this AFI

14. Protective

Aircraft

Shelter Vault

a. Facility

Single Point

Ground system resistance check

24 months Base Civil

Engineer This AFI

b. Visual inspection of grounding system

12 months Base Civil

Engineer This AFI

c. Continuity between arch and ground

(1 ohm or less)

24 months Base Civil

Engineer This AFI

d. (HAS)

Validate door hinge continuity (1 ohm or less )

24 months Base Civil

14 AFI32-1065 12 JANUARY 2015

e. (HAS)

Continuity between vault lip

(flange) and ground

(conduit) (1 ohm or less)

24 months Base Civil

Engineer This AFI

f. Continuity of installed

(permanent) bonds between metal masses and steel support

When notified of damage

Base Civil

Engineer This AFI

g. Visual inspection of permanent bonds between metal masses and steel support

Annually Base Civil

Engineer This AFI

15. Medical

a. Resistance validation

(25 ohms or less)

5 years Base Civil

Engineer

NFPA 99,

Standard

Health Care b.

Effectiveness of grounding system by voltage and impedance measurement s

Before acceptance of new facility or after service entrance modification

Base Civil

Engineer

AFI 41-203,

Electrical

Safety in

Medical

Treatment

Facilities;

NFPA 99

c.

Verification of continuity of receptacle grounding circuits

Annual

(semi-annual for critical care areas)

Base Civil

AFI 41-203

AFI32-1065 12 JANUARY 2015 15

16. Airfield

Lighting Vault

Single Point

Facility

Ground

Resistance check (25 ohms or less)

2 years Base Civil

Engineer This AFI

17. EMP

Hardened

Facilities

(These facilities may have special requirements

) Otherwise, resistance check (25 ohms or less)

2 years

DNA-A-86-

60, Vol 1-3

18. PMEL

a. Visual inspection of equipment bonds

Before each use User This AFI

b. Continuity check from equipment to static bus bar

(1 ohm or less)

Determined by user from

T.O. and equipment manufacturer

User

c. Checks involving in-house electronic equipment grounds

Determined by user from

T.O. and equipment manufacturer

User

d. Continuity and resistance test of facility ground (10 ohms or less)

5 years

Engineer This AFI

AFMAN 32-

16 AFI32-1065 12 JANUARY 2015

19. Special

Intelligence, Cyber, SCIF, UAS and

Other Special-

Use Facilities

a. TBD by

Authority

Having

Jurisdiction

(AHJ)

b. TBD by

AHJ

User

20. Surge

Protective

Devices

a. Visual inspection

After unscheduled power outages

User This AFI

b. Visual inspection Quarterly

Base Civil

Engineer This AFI

If utility is privatized, this does not apply; however safety and operational discrepancies and damage should be reported when observed.

As defined in NEC Article 500

Also known as Hardened Aircraft Shelter (HAS), as determined by current Security Forces

AFIs.

Base Civil Engineers will perform if separate medical facility maintenance branch does not exist, under Memorandum of Agreement.

Note: All incoming services should be verified for continuity by the service provider every 5 years (i.e., gas, telephone, signal lines, CATV).

1.3.4. Review the lightning protection system on each facility at least annually or after repair actions (including facility repairs and construction additions by contractors) have been completed.

1.4. Users. Users will maintain lightning and electrical grounding systems as identified in

Table 1.

2. Codes and Specifications. Follow applicable codes and specifications in Attachment 1 unless modified in this instruction, or deviations are justified due to local conditions. (T-0)

3. Required Maintenance. Perform required maintenance at the frequencies specified in Table

1. When possible, plan for and schedule maintenance when facility users will be least affected.

(T-0)

4. Recordkeeping and Review.

4.1. Inspectors and testers must compile and maintain records of their inspections and tests to include (T-0):

AFI32-1065 12 JANUARY 2015 17

4.1.1. A sketch of the grounding and lightning protection system showing test points, and where services enter the facility. Sketch should also show the location of the probes during the ground resistance test. (Separate sketches are suggested for static, earth ground, and lightning protection systems on large complex facilities.)

4.1.2. Date action was performed.

4.1.3. Inspector's or tester’s name.

4.1.4. General condition of air terminals, conductors, and other components.

4.1.5. General condition of corrosion protection measures.

4.1.6. Security of attachment for conductors and components.

4.1.7. Resistance measurements of the various parts of the ground terminal system.

4.1.8. Variations from the requirements of this instruction.

4.1.9. Discrepancies noted and corrective actions taken.

4.1.10. Dates of repairs.

4.2. Review records for deficiencies; also analyze the data for undesirable trends. If test values differ substantially from previous or original tests obtained under the same test procedure and conditions, determine the reason and make necessary repairs. (T-0)

4.3. Keep test and inspection records for a minimum of six inspection cycles. (T-1)

5. Forms. Suggest the use of Air Force general purpose forms (3100 series) to record tests. Use the format listed in MIL-HDBK-419A, Grounding, Bonding, and Shielding for Electronic

Equipments and Facilities for communications facilities. Provide copies of completed forms to the facility user. For munitions facilities maintained by host nation civil engineers, the using agency must receive a copy of the completed forms. (T-1)

6. Personnel Qualifications. Workers maintaining, repairing, modifying, and testing grounding systems must be thoroughly familiar with test equipment operation; lightning protection, grounding, and bonding theory and practices; referenced codes and standards; and specific requirements and procedures in this instruction. Attachments 2 through 5 provide information suitable for use in training and familiarization. (T-0)

7. Developing Procedures. The organization performing inspections and tests must develop procedures based on the requirements in this instruction. (T-0)

Section B—Grounding Resistance and Continuity Tests and Visual Inspections

8. Testing Requirements. See Attachment 6 for resistance and continuity test requirements for typical systems. Instruments must be able to measure 10 ohms +10 percent for ground resistance tests, and 1 ohm +10 percent for continuity testing. Only instruments designed specifically for earth-ground systems are acceptable for ground resistance testing. Follow the manufacturer’s instruction manual except as modified herein when using the instruments. Earth ground resistance should be less than 25 ohms unless specified different in this document. Periodic tests should be made at approximately the same time each year to minimize confusion resulting from

18 AFI32-1065 12 JANUARY 2015

seasonal changes (see Attachment 2). If the resistance measured during continuity tests is greater than 1 ohm, check for deficiencies and repair, then retest. When per- forming a continuity test over very long lengths of conductors (more than 20m with no parallel paths), readings above one ohm but less than 3 ohms may occur. This is acceptable. The MAJCOM electrical engineer may modify the test procedures due to local conditions, as long as the intent of the test is still achieved. (T-0)

9. Visual Inspections of Lightning Protection Systems. Inspect all visible parts of the system.

(T-0) Pulling or tugging on conductors and connections to insure soundness is a necessary part of these inspections, but be careful not to damage the system in the process. Visual/physical inspection must determine if (T-0):

9.1. The system is in good repair.

9.2. There are loose connections that might cause high resistance joints.

9.3. Corrosion or vibration has weakened any part of the system.

9.4. Down conductors, roof conductors, and ground terminals are intact.

9.5. Braided bonding wires are excessively frayed (cross sectional area reduced by half).

9.6. Ground wires on lightning protection masts are damaged by lawn mowers or other equipment.

9.7. Conductors and system components are securely fastened to mounting surfaces.

Relocate connections as necessary to better protect against accidental displacement.

9.8. Additions or alterations to the protected structure require additional protection.

9.9. Surge suppressive (overvoltage) devices appear damaged.

9.10. The system complies with applicable sections of NFPA 780, Standard for the

Installation of Lightning Protection Systems (Attachment 4) (T-0).

10. Visual Inspection of Facility Grounds. Unless otherwise specified by references in Table

1., conduct visual inspections as follows. Inspect all visible and accessible parts of the system.

Determine if they are in good condition and the installation meets NEC requirements

(Attachment 2) (T-0). Typical items to check:

10.1. The system is in good repair.

10.2. There are no loose connections.

10.3. The system neutral is grounded at the service entrance (this includes the connection to the grounding electrode).

10.4. Separately derived systems are properly grounded.

10.5. Flashover protection is installed on insulating fittings on underground metallic pipelines entering the facility.

10.6. Grounding systems within the facility are bonded together at ground level or below.

Section C—Grounding and Lightning Protection Requirements

AFI32-1065 12 JANUARY 2015 19

11. Introduction. This section covers requirements for grounding and lightning protection systems, including systems installed on or in areas such as explosives buildings, magazines, operating locations and shelters. Use these requirements when inspecting to determine compliance and when repairing or modifying systems. See AFMAN 91-201, Explosive Safety

Standards (T-1).

12. Testing and Inspecting Static and Lightning Protection Systems and Grounding:

12.1. Procedures. Use Attachment 4 and Attachment 5 as a guide for establishing proper maintenance procedures and a check during self-inspections.

12.2. Inspection and Testing. Inspect the static and lightning protection systems and grounding for buildings and facilities visually and electrically according to Sections A, Maintenance Policy and B, Grounding Resistance and Continuity Tests and Visual

Inspections, and the special requirements in this section (T-0).

12.3. Records. Keep records of test and inspections for explosives facilities for a minimum of six inspection cycles (see paragraph 4) (T-0). Figure 1 is an example sketch of a grounding and lightning protection system with test points.

20 AFI32-1065 12 JANUARY 2015

Figure 1. Example Sketch of Test Points (Typical).

AFI32-1065 12 JANUARY 2015 21

13. Static Protection

13.1. Equipment Grounding. The best methods to eliminate or reduce the hazard from static electricity are bonding and grounding. Bonding minimizes potential differences between conductive objects. Grounding minimizes potential differences between objects and the ground. Inspect and test facilities for compliance with NFPA 77, Static Electricity, which contains the minimum acceptable static grounding and bonding requirements for Air Force activities, except as modified herein (T-0).

13.1.1. Bonding and grounding wires must be large enough to withstand mechanical damage. Minimum size for existing bonds is AWG No. 8. Make repairs with wires no smaller than AWG No. 6 copper. Static grounds for portable or movable equipment must use braided cable for added flexibility. (T-0)

13.1.2. Static grounds must be 10,000 ohms or less, unless otherwise stated. Static electricity creates extremely small (milliamps) currents, so even this large resistance is small enough to bleed off static charges. But because the static grounding system must be connected to the facility grounding system, resistances of less than 25 ohms are common.

(T-0)

13.2. Static Bus Bars. Static bus bars are usually 2- by 1/4-inch copper bars installed on the interior wall of the facility. Bond static bus bars directly to each lightning protection down conductor where it crosses the down conductor if separation between the two is within NFPA

780 bonding distance and the bus or down conductor cannot be relocated. They must also be connected directly to the facility grounding electrode system. See Attachment 6 for testing requirements. Use static bus bars only for static grounding. Do not connect telephone grounds, electrical conduit or intrusion systems to this bus. Static bus bars must not be used as a grounding medium for these systems. As a general rule, do not connect a static bus to any facility metal body or use this bus to ground structural components of a facility;

however, coincidental connections of the bus bar through its anchoring/mounting system are acceptable as is the mounting of the static bars on the skin of a metal structure. Portable grounding straps from equipment to the static grounding bus are not real property. Visual inspections and continuity checks for these straps are the responsibility of the user. (T-0)

13.3. Belting Requirements. On equipment such as belt-driven compressors and conveyor belts, if static electricity is a hazard, use non-static-producing belting. Belting must have a resistance not exceeding 1,000,000 ohms when measured according to IEEE STD 142, chapter 3. (T-0)

13.4. Conductive Floor Grounds. If the facility requires conductive floors, the resistance of the floor must be less than 1,000,000 ohms. Additionally, the resistance between the floor and ground connections must not be less than 25,000 ohms. This requirement protects personnel from electric shock hazard and allows bleed off of static buildup in people and operating equipment. See Attachment 6 for testing requirements. The testing and using agency must keep a record of test results. (T-0)

14. Lightning Protection Systems. AFMAN 91-201 identifies explosives facilities that require lightning protection systems. Many other structures housing critical or sensitive supplies or

22 AFI32-1065 12 JANUARY 2015

equipment also require protection. The following requirements will be used as a guide for facilities that require lightning protection. (T-1)

14.1. General. Systems must comply with NFPA 780 and AFM 88-9, Chapter 3, Electrical

Design Lightning and Static Electricity Protection (except as modified herein). (T-0) Early streamer emission systems or charge dissipation systems are not permitted. Parts and materials must carry the Underwriters Laboratories (UL) label or equivalent. (T-0)

Otherwise, such components must be approved by the MAJCOM electrical engineer in charge of lightning protection. (T-2) Facilities in foreign countries may use host nation codes and standards if they offer equivalent protection, as determined by the MAJCOM electrical engineer with concurrence from HQ AFCEC/COSM and approval of the DoD

Explosive Safety Board (DDESB). (T-0) Otherwise, the Status of Forces Agreement (SOFA) must permit their use. Where the SOFA requires compliance with host nation codes, translate those required codes into English, make them available to all appropriate personnel, and perform necessary training. Maintain all installed systems according to this instruction. If not required, remove the LPS system with coordination through the using agency. (T-0)

14.2. Bonding Requirements. Adequate bonding is more important than grounding. Bonding ensures all metallic objects are at equal potentials, preventing dangerous flashovers. Inspect and test facilities for compliance with NFPA 780 and Attachment 3 of this instruction. (T-0)

14.3. Grounding Resistance. Low resistance is desirable but not essential for lightning protection. For most facilities, resistance to ground should be less than 25 ohms. If this cannot be achieved where only ground rods are used (no ground loop conductor), install a ground loop conductor. The resistance to ground of a ground loop system is acceptable even if greater than 25 ohms. See Attachment 2.

14.4. Lightning Protection For Explosives Facilities. Use the basic practices in Attachment

4, with the following additions:

14.4.1. The system must be designed for a 30.5-meter (100-foot) striking distance. (T-0)

14.4.2. Installation of ground wells (hand holes) at corner ground rods is recommended to aid access for testing.

14.4.3. Replace existing bolted connectors on down conductors and roof conductors needing repair with high compression or exothermic-weld type connectors. Connections to air terminals are an exception, but they must be tight and in good repair. Bolted connections to aluminum bodies (such as vents) and to metal bodies for the purpose of bonding are also acceptable. Brazing to metal bodies is allowed but not recommended due to the possibility of a cold weld with inadequate strength. (T-0)

14.4.4. Structural elements of a facility may serve as air terminals, down conductors, or the earth electrode.

14.5. Explosives Facilities with Large Perimeters. New explosives facilities (including igloos) with a perimeter over 91.4 meters (300 feet) that require lightning protection and do not use the structural steel as the air terminals must use either a mast system or an overhead wire system. See Attachment 4 for requirements. Since these systems provide better protection, and maintenance is easier, consider using this type of protection for other kinds of facilities. The MAJCOM may waive this requirement (overhead or mast system). (T-2)

AFI32-1065 12 JANUARY 2015 23

14.6. Protective Aircraft Shelters (PAS) (also known as Hardened Aircraft Shelter (HAS)).

PASs with interior steel arches or interconnected rebar (i.e., floor rebar that is connected to wall rebar) and grounded ventilators of metal at least 4.78 millimeters (0.188 inch) thick do not need air terminals. Metal ventilators less than 4.78 millimeters (0.188 inch) thick must be protected by an air terminal. All metal bodies in the PAS must be properly bonded and grounded. See Attachment 3. An adequate grounding system is also required. (T-0)

14.7. Air Force-approved inspectors, with authority to recommend acceptance of LPSs that protect explosives facilities and communications facilities, are limited to: (T-1)

14.7.1. Nationally recognized inspection agencies who have a minimum 10 years’ experience in inspection of LPS for explosives facilities on DoD or DoE installations and who have exhibited accuracy in identification of discrepancies, evidenced by no modifications having been required to the system during the warranty period (see UFC 3-

575-01).

14.7.2. Air Force personnel who have minimum 6 years’ experience in LPS maintenance and have taken an advanced lightning protection systems senior inspector course.

15. Surge Protection 15. Surge Protection is required IAW NFPA 780.(T-0) Surge protective devices (SPDs), formerly referred to as TVSS (transient voltage surge suppression), protect equipment from transient voltages resulting from lightning and switching surges and protect the upstream distribution system from the rapid switching effects of electronics. SPDs are most effective when used in the form of tiered protection. Tiered protection means providing protection at main distribution panels, at secondary or sub-panels and at the equipment point of use. For protection of non-real property installed equipment, refer to the equipment manufacturers’ requirements for surge protection.

15.1. Minimum Requirements for Surge Protective Devices for weapons storage areas

(WSAs), munitions storage areas (MSAs) and communications facilities are:

15.1.1. Standard, published, minimum 15-year unlimited replacement warranty on product (SPD). The entire unit shall be replaced upon detection of the failure of any mode. (T-1)

15.1.2. All mode (10 modes), directly connected protection elements (l-n, l-g, l-l, n-g)

(T-1)

15.1.3. All steel enclosure, with UL-approved fasteners. (T-1)

15.1.4. Internal over-current fusing on each phase for self-protection from failed component(s), and an internal disconnect for each phase. (T-1)

15.1.5. Individual component level thermal fusing(T-1)

15.1.6. Bi-polar protection (T-1)

15.1.7. The SPD shall contain continuous, self-monitoring devices with indicator lamps for each mode. These may be located inside enclosed areas such as mechanical rooms if an indicator lamp is provided in a visible area. It would be preferable for the indicator lamp to be installed in a location that can be seen from a vehicle, allowing maintenance

24 AFI32-1065 12 JANUARY 2015

personnel to drive large areas and quickly identify devices which have operated.

Indicator lamps that can be seen in this way will also allow maintenance personnel to assess whether a group of SPDs in a single area have operated. (T-1)

15.1.8. Cable connection between a bus and SPD shall be minimum No. 10 AWG for installation at main distribution panels and sub-panels. (T-1)

15.2. Igloos or Earth Covered Magazines (ECMs): up to 60A service

15.2.1. Visible indicators of SPD operation on exterior of facilities. Drive-by visual inspections may be an effective means of inspecting SPDs.

15.2.2. 60kA/mode to allow the following:

15.2.3. 180kA/phase peak service surge current

15.2.4. Non-modular. The entire unit shall be replaced upon detection of the failure of one mode of operation. Ease of installation shall not be traded for possible minimized protection level. (T-1)

15.3. Maintenance Facilities: 400-600A service (T-1)

15.3.1. Visible indicators of SPD operation on exterior of facilities. Drive-by visual inspections may be an effective means of inspecting SPDs

15.3.2. 180kA/mode to allow the following:

15.3.3. 240kA/phase peak service surge current

15.3.4. Non-modular. The entire unit shall be replaced upon detection of the failure of one mode of operation. Ease of installation shall not be traded for possible minimized protection level. (T-1)

15.4. Communications Facilities: up to 1800A

15.4.1. Visible indicators of SPD operation on exterior of facilities or audible alarm

15.4.2. 200kA/mode (this will allow the following requirement)

15.4.3. 600kA/phase peak service surge current

15.4.4. Non-modular. The entire unit shall be replaced upon detection of the failure of one mode of operation. Ease of installation shall not be traded for possible minimized protection level.

15.5. General Requirements: (T-1)

15.5.1. Nominal discharge current test @ 20kA (UL testing allows 10kA or 20kA, but testing at 10kA is not allowed for Air Force facilities).

15.5.2. Unit Type (UL 1449.2006, 9/29/09):

15.5.2.1. Type 1 unit in front of service panel

15.5.2.2. Type 1 or 2 unit on load side of service panel (not needed for igloos)

AFI32-1065 12 JANUARY 2015 25

15.6. SPDs shall be provided on proprietary equipment by the communications provider or the tenant communications agency or group. (T-1)

JUDITH A. FEDDER, Lieutenant General, USAF

DCS/Installations, Logistics & Mission Support

26 AFI32-1065 12 JANUARY 2015

Attachment 1

GLOSSARY OF REFERENCES AND SUPPORTING INFORMATION

References

Code of Federal Regulations

7 CFR 1724.50 – Compliance with National Electrical Safety Code

14 CFR 420.71 – Lightning Protection

29 CFR 1910 – Electrical Standards – Final Rule

30 CFR 56.12069 – Lightning Protection for Telephone Wires and Ungrounded Conductors

GAO Publications

GAO-005-682R, Federal Real Property: Lightning Protection Systems for Federal Buildings

DoD Publications

DoD 6055.09M, DoD Ammunition and Explosives Safety

D0D Explosives Safety Board Technical Paper 22, Lightning Protection for Explosives Facilities

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

Federal Information Processing Standards (FIP) Pub 94, Guidelines on Electrical Power for ADP

Installations. (Available from National Technical Information Center, US Department of

Commerce, Spring- field VA 22161.)

MIL-STD188-124, Grounding Bonding and Shielding for Common Long Haul/Tactical

Communications Systems, (1992)

Air Force Publications

AFI 32-1063, Electrical Power Systems

AFI 91-203, Air Force Consolidated Occupational Safety Instruction

AFI 41-203, Electrical Safety in Medical Treatment Facilities

AFMAN 91-201, Explosive Safety Standards

AFJMAN 32-1082, Facilities Engineering, Electrical Exterior Facilities

AFM 85-16, Maintenance of Petroleum Systems

AFM 88-9, Chapter 3, Electrical Design Lightning and Static Electricity Protection

Other

ANSI C2, National Electrical Safety Code (IEEE). (Copies available from The Institute of

Electrical and Electronics Engineers, 345 East 47th Street, New York NY 10017.)

DNA-A-86-60, V1-3, DNA EMP Engineering Handbook for Ground-Based Facilities

IEEE STD 142, IEEE Recommended Practice for Grounding for Industrial and Commercial

Power Systems (Green Book)

AFI32-1065 12 JANUARY 2015 27

IEEE STD 446, Recommended Practice for Emergency and Standby Power (Orange Book)

NFPA 70, The National Electrical Code

NFPA 77, Static Electricity

NFPA 99, Standard Health Care Facilities

NFPA 780, Standard for the Installation of Lightning Protection Systems

Cold Regions Research and Engineering Laboratory (U.S.), Electrical Grounding in Cold

Regions

NETA MTS, Standard for Maintenance Testing Specifications for Electrical Power Equipment and Systems

Additional References

IEEE STD 81, IEEE Guide for Measuring Earth Resistivity, Ground Impedance, and Earth

Surface Potentials of a ground System

IEEE STD 1100, IEEE Recommended Practice for Powering and Grounding Sensitive

Electronic Equipment (Emerald Book)

Notes:

Available from The Institute of Electrical and Electronic Engineers, 345 East 47th Street, New

York NY 10017.

Available from National Fire Protection Association, 1 Batterymarch Park, Quincy MA

022699990.

Available electronically at: http://acwc.sdp.sirsi.net/client/search/asset/1012700

Abbreviations and Acronyms

AHJ—Authority Having Jurisdiction

ANG—Air National Guard

ANSI—American National Standards Institute

AWG—American wire gauge

BBF—basic bonding formula

BCE—Base Civil Engineer

DDESB—Department of Defense Explosive Safety Board

DoD STD—Department of Defense Standard

EMP—electromagnetic pulse

FIPS—Federal Information Processing Standard

IAW—In Accordance With

IEEE—Institute of Electrical and Electronics Engineers http://acwc.sdp.sirsi.net/client/search/asset/1012700

28 AFI32-1065 12 JANUARY 2015

IG—isolated ground

LOX—liquid oxygen

MAJCOM—major command

MIL HDBK—Military Handbook

MOV—metal oxide varistor

NBN—no bonding needed

NEC—National Electrical Code

NFPA—National Fire Protection Association

PAS—Protective Aircraft Shelter (also known as Hardened Aircraft Shelter (HAS))

POL—petroleum, oils, lubricants

PMEL—Precision Measurement Equipment Laboratory

SDS—separately derived system

SOFA—Status of Forces Agreement

T.O.—Technical Order

WS3—Weapon Storage and Security System

Terms

Air Terminal—The component of the lightning protection system intended to intercept lightning flashes, placed on or above a building, structure, or tower. A building’s grounded structural elements may be used as an air terminal. Sometimes air terminals are referred to as lightning rods.

Bonding—An electrical connection between an electrically conductive object and a component of a lightning protection system that is intended to significantly reduce potential differences created by lightning currents.

Conductor, Bonding—A conductor used for equalization potential between metal bodies and the lightning protection subsystem.

Catenary System—A lightning protection system consisting of one or more overhead wires.

Each overhead wire forms a catenary between masts, and serves the function of both a strike termination device and a main conductor.

Conductor, Main—A conductor intended to carry lightning currents from the point of interception to ground terminals.

Copper Clad Steel—Steel with a coating of copper bonded on it.

Down Conductor, Lightning—The conductor connecting the roof conductors or overhead ground wire to the earth ground subsystem.

AFI32-1065 12 JANUARY 2015 29

Ground Loop—A conductor, buried 3 to 8 feet from a structure, encircling the structure interconnecting ground electrodes. The conductor may be connected to buried copper or steel plates or ground rods.

These are installed to establish a low resistance contact with earth. (Also referred to as counterpoise, loop conductor, or closed loop systems.)

Facility Ground System—The electrically interconnected system of conductors and conductive elements that provides multiple current paths to earth. The facility ground system can include the earth electrode subsystem, lightning protection subsystem, signal reference protection subsystem, fault protection subsystem, static ground subsystem, as well as the building structure, equipment racks, cabinets, conduit, junction boxes, raceways, duct work, pipes, and other normally non-current-carrying metal elements.

Ground—The electrical connection to earth primarily through an earth electrode subsystem.

This connection is extended throughout the facility by the facility ground system.

Ground Terminal—The portion of a lightning protection system such as a ground rod, ground plate, or ground conductor that is installed for the purpose of providing electrical contact with the earth.

Inherent Bond—Where metal bodies located in a steel-framed structure are electrically bonded to the structure through the construction.

Integral System—A system which uses air terminals mounted directly on the structure to be protected.

Lightning Protection System—A complete system consisting of components (such as air terminals, interconnecting conductors, ground terminals, surge suppression devices, and other connectors or fittings) and subsystems required to assure a lightning discharge will be safely conducted to earth.

Mast System—A lightning protection system using masts that are remote from the structure to provide the primary protection from a lightning strike.

Overhead Wire System—System using conductors routed over the facility, at a specified height, designed to provide the required zone of protection. Also known as overhead shield wire system and catenary system.

Side Flash—Electrical arcing between metal objects caused by difference of potential from a lightning discharge.

Strike Termination Device—A component of a lightning protection system intended to intercept lightning flashes and connect these flashes to a path to ground. Strike termination devices include air terminals, masts, permanent parts of structures, and overhead wires in catenary systems.

TEMPEST—Unclassified name for investigation/study of compromising emanation.

Zone of Protection—Space below and adjacent to a lightning protection subsystem that is likely to avoid direct lightning discharges.

30 AFI32-1065 12 JANUARY 2015

Attachment 2

BASIC REQUIREMENTS FOR GROUNDING SYSTEMS (T-0)

A2.1. Types of Grounds. There are five basic types of grounding systems which must be inspected if present in a facility: static grounds, equipment grounds, electrical system grounds, lightning grounds, and signal reference grounds.

A2.1.1. Static Grounds. A static ground is a connection between a piece of equipment and earth to drain off static electricity charges before they reach a sparking potential. Typically, static grounding involves connecting large metal objects such as fuel tanks or aircraft to earth through a ground rod. Static grounds are not part of an electrical power system. But if an equipment grounding conductor is adequate for power circuits, it is also adequate for static grounding.

A2.1.2. Equipment Grounds. Equipment grounding involves interconnecting and connecting to earth all non-current-carrying metal parts of an electrical wiring system and equipment connected to the system. The purpose of grounding equipment is to ensure personnel safety by reducing any charge in an equipment item to near zero volts with respect to ground.

Equipment ground must be capable of carrying the maximum ground fault current possible without causing a fire or explosive hazard, until the circuit protective device clears the fault.

An example is the bare copper wire or green insulated conductor connected to the frames of electric motors, breaker panels, and outlet boxes. The equipment ground is connected to an electrical system ground (neutral) only at the electrical service entrance of a building and should not exceed 25 ohms to ground.

A2.1.3. Electrical System Ground. The purpose of electrical system grounds is to stabilize voltage to ground and give a low impedance path for fault currents. One wire or point of an electrical circuit in an electrical system ground is connected to earth. This connection is usually at the electrical neutral (though not always), and is called the "system ground."

Examples of electrical system grounds are generator or transformer neutral points connected to earth, and the grounded neutral of an interior wiring system. The resistance of most electrical system grounds below 600 Vac should not be more than 25 ohms. Medium voltage systems (1-15kV) frequently are grounded through a resistor (or reactor) and may exceed 25 ohms. This limits ground fault current to a manageable level.

A2.1.4. Lightning Grounds. The purpose of lightning grounds is to safely dissipate lightning strokes into the earth. They are part of a lightning protection system which usually includes air terminals (lightning rods), down conductors, arresters, and other connectors or fittings required for a complete system. The sole purpose of a lightning protection system for a facility is to protect the building, its occupants, and contents from the thermal, mechanical and electrical effects of lightning.

A2.1.5. Signal Reference Grounds. The purpose of a signal reference ground is to provide a low impedance signal reference system for electronic equipment to minimize noise-induced voltages and thereby reduce equipment malfunctions. Common configurations include planes and grids. See FIPS Pub 94, Guidelines on Electrical Power for ADP Installations, for details.

AFI32-1065 12 JANUARY 2015 31

A2.1.6. Subsystem Grounds. Each of the grounding systems described above may be a subsystem of a total facility grounding system. All grounds (and subsystems) must be bonded together according to NFPA 780 and NFPA 70, The National Electrical Code. MIL-HDBK-

419A contains example sketches of grounding subsystem interconnections.

A2.2. NEC Grounding Requirements. Electrical systems and circuit conductors are grounded to limit voltages during lightning and to facilitate overcurrent device operation in case of a ground fault. The NEC allows the system neutral to be grounded and limits the location of this neutral to earth connection to the source side of the service entrance disconnect or at a separately derived system (NEC, articles 250-23 and 250-26). Since the neutral will carry current under normal operating conditions, the NEC often refers to it as the grounded conductor. If a building service is at less than 1000 volts, a neutral conductor (if required by NEC, article 250-5) must be run to each service entrance from the servicing transformer and bonded to the disconnecting panel enclosure. In contrast to the neutral, the equipment ground conductor (green insulated or bare wire) is referred to as the grounding conductor. The grounding conductor is used to ground metallic enclosures and motor frames, and must be connected to neutral only on the source side of the service entrance disconnect.

A2.2.1. Facility Ground. The NEC requires a premises wiring system to have a grounding electrode at each service. This electrode may be of several different types or systems. Each of the types listed below must be bonded together to form the grounding electrode system.

Where none of the listed electrodes are present, ground rods or ground plates must be used.

Ground rods must be at least 2.44 meters (8 feet) in length (10 feet for lightning protection;

see Attachment 4) and no closer than 1.83 meters (6 feet) from other rods or plates. Ground rods or plates must not be aluminum. The Air Force also prohibits stainless steel ground rods.

A2.2.1.1. Where a metal underground water pipe (uncoated) is in direct contact with the earth for 3.05 meters (10 feet) or more, do not bond around insulation flanges installed for cathodic protection. If the underground water pipe is the only electrode available, ground rods must supplement it.

A2.2.1.2. The metal frame of a building where the building is effectively grounded.

A2.2.1.3. An electrode encased by at least 51 millimeters (2 inches) of concrete, made of at least 6.1 meters (20 feet) of one or more steel reinforcing bars, located within and near the bottom of a concrete foundation or footing in direct contact with the earth. This is known as a Ufer ground.

A2.2.1.4. A ground ring encircling the building at least 0.76 meters (2.5 feet) deep. The ground ring must be at least 6.1 meters long and use at least AWG No. 2 copper (1/0 copper for lightning protection ground ring conductor; see Attachment 4).

A2.2.2. Separately Derived Systems (SDS). A separately derived system is a premises wiring system where power is derived from a generator, transformer, or converter. An SDS has no direct electrical (metallic) connection, including the neutral, to the supply conductors originating in another system.