Taken directly out of the methodology section of our DA Pam CAP plan-

SLP has created Compliance Action Plans (CAPs), which are ready to be used in the field for DA Pam 385-64 compliance. We are ready to go to your installation. Also, check out the Ground Resistance Testing section. 

Testing accomplished under DA Pam 385-64 with consideration of NFPA 780 and IEEE-81.

Earth Resistance Testing-Ground testing device-AEMC 4620 utilized for 3-point fall of potential ground testing

and bonding.

Standards of Testing Utilized:

F–1. General requirements LPS will be visually inspected and tested as specified in table 16–1 for electrical

resistance and adequacy of grounding. Any system will be considered deficient if the required resistance value

cannot be met. Any system found to be deficient will be repaired. If the deficiency cannot be corrected

immediately, the LPS test/maintenance/ace personnel must record the deficiency on the test record and

initiate the following actions: a. Notify the installation safety office. b. If the deficient system protects an AE

storage structure, the custodian of the contents must be notified. c. Interim control measures will be

developed based on a risk assessment in accordance with AR 385–10. The risk assessment must consider

ceasing operations in and around the building and rewarehousing the contents for storage facilities. A decision

not to rewarehouse the contents of a storage magazine is justified only when the risk of rewarehousing

exceeds the risk associated with the deficient LPS. When the use of the facility continues, maintenance

to achieve the required resistance must be accomplished as soon as possible.

F–2. Visual inspection of lightning protection subsystem Components of the subsystem will be inspected for the

following: a. Subsystem will meet the requirements specified in NFPA 780. b. Components will not be broken.

c. Components will be in good repair. d. Components will be free of corrosion. Discoloration of materials is not

considered corrosion. e. Components will be free of breaks, cuts, and damage that will affect equipment

integrity. f. Bonding straps will not have more than 50 percent of the wire strands broken, and the remaining

portion of the strap will meet the minimum strap thickness and width/cross-section requirements of table

16–4. g. Components will not be weakened by vibration. h. Components will be securely fastened to their

mounting surfaces and are protected against accidental mechanical displacement as required. i. There

have not been additions or alterations to the protected facility which would require additional protection

or testing.

F–3. Electrical testing of lightning protection subsystems a. Test instruments. Electrical tests consist of

measuring the bonding resistance of the lightning protection subsystem components. The instrument must

be capable of measuring resistance up to 1 ohm +10 percent. The manufacturer’s instruction manual will be

followed to ensure proper use of the instrument. b. Requirements for the bonding test are as follows:

(1) The bonding test (see figure F–1) consists of firmly attaching one lead of the ohmmeter to the down

conductor where it enters the earth. The earth electrode system will be disconnected when practical.

The other lead will then be firmly attached to:

(a) The other down conductor where it enters the earth (see figure F–1).

(b) Each component of the lightning protection subsystem.

(c) Each component of all other subsystems on the facility.

(d) All large metal bodies (a surface area equal to or greater than 400 square inches) that are bonded to the

lightning protection subsystem.

(2) Read the meter. If the meter reading is one (1) ohm or less, the lightning protection subsystem is

acceptable. Record the reading. If the meter reading exceeds one ohm, the lightning protection subsystem is

not acceptable.

(3) If lightning protection down conductors are not accessible, the air terminal base may be used as an alternate

reference test point for the meter test lead. The air terminal selected should be the same one used to do the

3-point fall of potential test, which validates the system’s resistance to earth.

Requirements:

15-2 Building

f. Each magazine will be provided with appropriate means of lightning protection in accordance with chapter 1

6, Section IV

16–5. Electrical service lines in ammunition and explosives areas a. Each service line will be run underground

from a point at least 50 feet away from the building. The exterior line side of the main disconnecting switch or

circuit breaker must have suitable lightning arrestors. See paragraph 8–14 and table 8–1 for separation distance

for electrical lines. b. Surge (lightning) arresters will be required and installed as specified in NFPA 70,

Article 280.

16–6. Low voltage utility lines Local telephone service and similar low voltage intercom or alarm systems must

also comply with the same underground routing for the last 50 feet. Surge protection, even for lines that run

underground, will be provided to shield against any severe electrical surges from a nearby lightning strike or

excessive power through the line from other outside sources, such as broken power lines. Surge suppression

for incoming conductors must include suppression at the entrance to the building from each wire to ground.

16–11. Ordnance grounds

Ordnance grounds are used to ensure that electric currents do not flow between

ordnance components when they come in contact or are assembled. These currents can be produced by

common mode voltages induced in-ground loops, ESD of one component into another, and potential

differences created in the facility's ground system due to direct lightning strikes or near misses.

a. Ordnance grounds are electrically separated from all other ground systems (and objects connected to other

grounding systems). At former Navy installations, ordnance grounds and ground subsystems may be

connected to the secondary ground girdle at a single point.

b. Where they exist, ordnance grounds will be maintained.

16–13. Ammunition and explosives facility grounding

a. AE facilities will be provided with a ground system to provide personnel, equipment, and facility protection.

Personnel safety is provided by low impedance grounding and bonding for personnel, equipment, DA PAM

385–64 • 24 July 2023 131 metallic objects, and piping to prevent voltages sufficient to cause a shock hazard

or initiate AE within the facility.

b. A facility ground system is composed of the earth electrode subsystem and one or more of the following

subsystems:

(1) Static electricity charge dissipation subsystem.

(2) Ordnance ground subsystem.

(3) Instrument ground subsystem.

(4) Lightning protection subsystem.

(5) Structural ground subsystem.

(6) Fault protection subsystem.

(7) Power service grounds subsystem.

c. The AE facility grounding system at all Army installations will be visually inspected and electrically tested at

the required intervals for values specified in table 16–1. (1) General requirements are as follows:

(a) The garrison or installation safety officer, unless an alternate officer is specifically designated by the

garrison or SC, will maintain the inspection and test reports and/or records for the last six inspection cycles

(12 years for records on a 24-month interval cycle).

(b) Personnel responsible for maintenance, inspection, and testing must

be familiar with the fundamentals described in NFPA 780 and herein as they relate to AE facilities to ensure the

requirements of this pamphlet are met.

(2) All required maintenance will be performed on all grounding systems.

(3) Results of all electrical tests will be recorded. Any unacceptable conditions will be reported to the appropriate

office for resolution. d. Grounding system material will be in accordance with NFPA 70, Article 250.

16–14. Earth electrode subsystem

The earth electrode subsystem establishes the electrical connection between the facility and the earth. This

connection is necessary for static electricity dissipation, useful in power fault protection, and aids in minimizing

electronic noise from communications and instrumentation. It is a network of electrically interconnected rods

and/or cables installed to establish a low resistance contact with the earth. Electrodes are usually buried or

driven beneath the earth’s surface. Older garrisons or installations may also find that buried metal plates,

cones, pipes, grids, wells, and/or grounded railroad tracks are used as the earth electrode subsystem. Only

ground rods, ground loops, combinations, variations, and saltwater grounds are authorized for new construction

or major renovation projects. a. Earth electrodes will be placed at uniform intervals about the protected facility

as required; the grouping of earth electrodes on one side of a facility is prohibited. Earth electrodes will be set

not less than 3 feet or more than 8 feet from the structure. The type and size of the earth electrode subsystem

will depend on local soil conditions. Test borings and/or soil resistance tests performed in the areas before

construction will be used for deciding on an adequate earth electrode system. All connections will be tested for

electrical resistance, and the entire earth electrode subsystem will be tested to ensure that resistance to earth

meets the requirements of table 16–1. b. The subsystem must be tailored to reflect the characteristics of the

site and requirements of the facility. It must be properly installed, and steps must be taken to ensure that it

continues to provide a low resistance connection to earth throughout the facility's life. To achieve these

objectives:

(1) Before beginning the design, conduct a survey of the site where the earth electrode subsystem is to be

installed. Through this survey, determine the resistance of the soil, identify significant geological features,

gather information on architectural and landscape features which may influence the design of the

subsystem, and review local climate effects. (If possible, conduct this survey in advance of the final site

selection to avoid particularly troublesome locations.)

(2) As the site survey's first step, measure the soil's resistance at several points over the area of the planned

facility. Even the smallest facility, in so far as the earth electrode subsystem is concerned, will affect an area at

least 15 meters by 15 meters (50 feet by 50 feet). For larger facilities, the area is assumed to extend at least

6 meters (20 feet) beyond the basic building or structural outline, the ground floor plan. The soil resistance

must be known over the area encircled or covered by the earth electrode subsystem.

(3) Design an earth electrode subsystem appropriate for the site. DA PAM 385–64 • 24 July 2023 132

(4) Install the subsystem in accordance with the recommended procedures.

(5) Finally, measure the resistance to earth of the subsystem to verify that it meets the goals or design

specifications.

c. Only ground rods, ground loops, combinations, and variations thereof, and saltwater grounds are authorized

for new or renovation projects.

(1) Acceptable resistances to earth values are easiest to achieve when ground rods are driven to the depth

determined by the soil resistance test.

(2) A ground loop (counterpoise) subsystem will be installed if one of the following conditions are met:

(a) The minimum numbers of ground rods are driven to the depth determined by the soil resistance test, and the

required resistance to earth value is not achieved. (b) For grounding systems other than lightning protection

drive, as a minimum, two additional ground rods (see table 16–2 for minimum ground rod requirements) to the

depth determined by the soil resistance test.

(c) For grounding systems for LPS drive, as a minimum, one additional ground rod (see table 16–2 for minimum

ground rod requirements) to the depth determined by the soil resistance test.

(d) The results of the soil resistance test and cost analysis may indicate that installing ground rods would not be

cost-effective due to the need for excessively long ground rods. The results of the soil resistance test and cost

analysis must be kept on file.

(3) Access to the earth electrode subsystem will be provided by installing one or more grounding wells at

each new facility or at facilities undergoing a major renovation. Acceptable types of grounding wells are

shown in figure 16–1.

16–15. Bonding

(3) Soft soldering is not permitted for interconnections between elements of lightning protection networks by

either the NFPA 780 or the Underwriter’s Master Labeled System and is therefore not permitted at

Department of the Army activities.

Continued...

(1) New installation or renovation requirements are as follows:

(a) Ground rods will meet the requirements of NFPA 70 except when bonded to a lightning protection sub-

system. They then will not be less than three-quarters of an inch in diameter and 10 feet in length. Rods

will be copper-clad steel, solid copper, or stainless steel. Ground rods will be free of paint or other non-

conductive coatings. Ground rods will be located clear of paved surfaces, walkways, and roadways. Rods

will be driven so that the tops are at least 12 inches below the finished grade and located 3 to 8 feet beyond

the perimeter of the building foundation. Mustow topsoil over bedrock or dense coral may make it impractical

to bury ground rods or a counterpoise to the required level below grade. In these instances, using extended

down conductors or buried open plates, as described in chapter 4 of NFPA 780, provides an acceptable

alternative to the vertical burial of 10’ long rods. Protect threaded area of rods when driving the rods into the

ground. Threaded couplings will be used when it is necessary to drive multiple lengths of ground rods into the

earth.

(b) Ground rod quantity requirements. See table 16–2.

(2) For visual inspection requirements, see table 16–1 and appendix D, paragraph D–2.

(3) For electrical test requirements, see table 16–1 and appendix D, paragraph D–4.

(4) For Existing ground loop systems built under

Navy specifications (see figure 16–6.)

Section V Lightning Protection

16–19. Fundamental principles of lightning protection

a. NFPA 780 (2023 edition), “Standard for the Installation of Lightning Protection Systems,” will be the

guidance for LPS employed to protect army AE facilities and sites.

b. The fundamental principle for protecting life and property against lightning is allowing a lightning discharge

to enter or leave the earth without damage or loss. A low impedance path should be offered, which the

discharge current will follow in preference to all alternative high impedance paths offered by building materials

such as wood, brick, tile, stone, or concrete. When lightning follows the higher impedance paths, damage may

be caused by the heat and mechanical forces generated during the discharge passage. Most metals, being

good electrical conductors, are virtually unaffected by either heat or mechanical forces if they are large enough

to carry the current that can be expected. The metal path must be continuous from the earth electrode system

to the air terminal. Care should be exercised in selecting metal conductors (see table 16–4) to ensure the

integrity of the lightning conductor for an extended period. In most atmospheres, a nonferrous metal such as

copper or aluminum will provide a lasting conductor free of the effects of rust or corrosion.

c. Parts of structures most likely to be struck by lightning are those that project above surrounding parts, such

as chimneys, ventilators, flagpoles, towers, water tanks, spires, steeples, deck railings, antennas, shaft-houses,

gables, skylights, dormers, ridges, and parapets. The roof edge is the part most likely

to be struck on flat-roofed buildings.

d. An LPS consists of three basic parts that provide the low impedance metal path required:

(1) A system of air terminals or overhead wires on the roof and other elevated locations;

(2) A system of earth electrodes, and

(3) A conductor system (down conductor) connecting the air terminals to the earth electrode system.

e. Properly located and installed, these basic components described in paragraph 16–19.d improve

the probability that lightning discharge will be conducted harmlessly between the air and ground terminals.

16–20. Locations requiring a lightning protection system

a. LPS will be installed on all facilities and/or locations used for development, manufacturing, testing, handling,

storage, inspection, holding, or maintenance of AE.

b. An LPS will be required at a demilitarization or disposal site when:

(1) Personnel are required to work or remain at the site during the approach of or during a lightning storm.

(2) The respective commander can determine whether an LPS is necessary to protect personnel or equipment

based on a thoroughly documented risk assessment. The documentation will be maintained in records at the

appropriate safety office. c. Underground storage with metal or structural parts that have less than 2 feet of

earth cover will be protected as an AGS. d. NFPA 780, Section 8.1.1, currently exempts AE structures that

contain HD 1.4 AE or a structure containing an HC/D with a NEW of less than 25 pounds from LPS

requirements. However, this is not authorized by current DoD and Army guidance

16–21. Locations NOT requiring lightning protection

Under conditions specified in the following subparagraphs, lightning protection may be omitted from certain AE

facilities. If lightning protection is not installed on a facility, the reasons for not protecting the facility must be

documented and kept with DDESB/USATCES ESP documentation. Bonding and surge suppression require-

ments still apply.

a. An LPS may be omitted on facilities equipped with an adequate lightning warning system (see table 16–4)

when all the following conditions can be met—

(1) Operations can be terminated before the storm strikes;

(2) All personnel can be evacuated to IBD; and

(3) The expected damage due to a lightning strike will not seriously affect the garrison or installation mission.

b. An LPS may be omitted on facilities without a lightning warning system where—

(1) Personnel are not expected to sustain injury; and

(2) The resulting economic loss of or to the facility, it contents, or surrounding facilities is minimal.

c. Lightning protection may be omitted on facilities that—

(1) Contain only AE that cannot be initiated by lightning;

(2) As determined by USATCES and approved by DDESB; and

(3) No fire hazard exists.

16–22. Requirements for lightning protection systems

a. Army installation SCs; Army activity Commanders, when storing AE on a DoD installation under the control of

another Military Service; or an Army Commander’s designated representative who has the appropriate authority

are required to ensure the adequacy of LPS for existing AE facilities or accept the risk associated with a waiver

or exemption of LPS requirements. To meet this condition, the following requirements must be met:

(1) A Facility Engineer (FE) has determined that the LPS is compliant with or equivalent to the criteria

in DESR 6055.09, NFPA 780, and this pamphlet and, therefore, is adequately protective.

(a) The Army Commander or Army Commander's designated representative must have verified the FE

to be a qualified person in compliance with AR 385–10 (a qualified FE). AR 385–10 and NFPA 70e indicate that

a qualified person is "... one who has demonstrated skills and knowledge related to the construction and

operation of electrical equipment and installations, and has received safety training to identify and avoid the

hazards involved."

(b) At a minimum, the qualified FE making the determination must have successfully completed at

least one of the following DAC courses:

1. Ammo-28 Army Electrical Explosives Safety (4E–F32/645–F16 (MC));

2. Army Electrical Explosives Safety (CERT) (4E–F33/645–F17 (DL));

3. Navy Electrical Explosive Safety (CERT) (4E–F35/645–F19 (DL)); or

4. Air Force Electrical Explosive Safety (CERT) (4E–F38/645–F22 (DL)).

(2) The Army Commander or Army Commander’s designated representative must:

(a) Accept the risk associated with waiving or exempting LPS requirements for the AE facility and document in

DA Form 7632; and

(b) Approve actions taken to mitigate the risk.

b. A qualified FE will review LPS test and inspection reports and ensure that necessary maintenance is

being conducted and repairs made. The installation’s Safety Office or the Army activity storing munitions

on a DoD installation under the control of another Military Service will maintain records that document

tests, inspections, and repairs for at least six inspection cycles.

c. RESSs will include a statement that:

(1) The design and installation of LPS meet the criteria of DESR 6055.09, NFPA 780, and this pamphlet or

provides equivalent protection as verified by a qualified FE; or

(2) The requirement for an LPS has been waived or exempted with the associated risk accepted by the

Army Commander or Commander’s authorized representative.

d. USATCES approval of a RESS is the Army’s acceptance of the adequacy and protectiveness of the

LPS. USATCES concurrence with the risk the Army Commander or Commander’s authorized representative

provides is the Army’s concurrence with the risk being accepted.

16–26. Lightning warning systems

a. Lightning warning systems provide a positive, reliable means of continuously monitoring and recording

atmospheric voltage gradient. They can detect atmospheric conditions that may produce lightning in the

vicinity. Lightning warning systems installed and properly maintained can detect thunderstorms up to 200

miles away and indicate the direction of approach.

b. Locations relying on a lightning warning system instead of LPS will establish specific procedures for

terminating AE operations at the approach of a thunderstorm. These procedures will be based on the

sensitivity of the operation involved and the time required to terminate operations safely. At the minimum, the

lightning warning system must allow termination of AE operations and evacuation before the storm is 10 miles

from the location.

c. Location without lightning warning systems will also be required to develop detailed procedures for evacu-

ating

AE facilities at the approach of a storm. These procedures will address at a minimum:

(1) The decision to terminate an operation and/or evacuate on a case-by-case basis pending an evaluation of

the risks to operations and support personnel.

(2) Procedures must identify a responsible individual who has the authority to decide when an evacuation is

necessary. Following are some examples of facilities that should be evacuated in the event of a probable

electrical storm:

(a) All operations involving EIDs and exposed explosives or propellants.

(b) Buildings containing explosives, dusts, or vapors, whether, or not equipped with approved LPSs and

locations within ILD of these facilities.

(c) Outdoor operations with unpackaged munitions or ammunition operations being conducted without lightning

protection. 16–27. Structural grounds On all new construction and extensive renovation, the structural steel in

all AE facilities will be bonded to the facility grounding system. No greater than 1-ohm resistance will exist

between the structural steel and the grounding system. Testing must be performed in accordance with

appendix F. 16–28. Grounding For details on grounding, use table 16–4 and Section III.

16–29. Surge protection

a. An LPS for AE structures will use surge protection for incoming conductors meeting the requirements of

NFPA 780.

b. Power and communication lines will enter the facility in underground shielded cables or in metallic conduits

which enter the ground at least 50 feet from the facility. In addition, intrusion detection systems and other

metallic lines will run underground for at least the last 50 feet up to the structure. Surge suppression for

incoming conductors must include suppression at the entrance to the building from each wire to ground.

The use of low-pass filters will be considered for added protection on specific critical electronic loads as

determined by the user.

c. Fiber optic cables do not need to run underground before entering the building.

d. Steam, water, and air conditioning lines may run above-ground as long as they are bonded to the

structure’s LPS before entering the structure. If these lines are not bonded to the LPS, they will run the last

50 feet to the building underground.