832571250 PWS Appendix C - Electrical Safety Program.pdf

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EFFECTIVE DATE: 19 APRIL 2023

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Table of Contents

1. PURPOSE

2. SCOPE

2.1. Arrangement

3. REFERENCES

4. DEFINITIONS AND ACRONYMS

4.1. SHALL/SHALL NOT, Should/should not, and May Statements

4.2. Definitions

4.3. Acronyms

5. RESPONSIBILITIES

5.1. Supervision/Management

5.2. Employees

5.3. Contractors

6. REQUIREMENTS

6.1. General Safety Requirements

6.2. Circuit Breakers and Switches

6.3. Interlocks

6.4. Ground Fault Circuit Interrupters (GFCIS)

6.5. Energized Electrical Work

6.5.1. Energized Electrical Work Criteria

6.5.2. Energized Electrical Work Permit Exemption

6.6. Two-person Rule

6.7. Training

6.7.1. Emergency Actions

6.7.2. Contractors

6.8. Personal Protective Equipment

6.8.1. Protective Apparel and Equipment

6.8.2. Insulated Glove Usage

6.8.3. Insulated Line Hose, Sleeves, Mats and Blankets

6.8.4. Insulated Tools and Equipment

6.8.5. Emergency Situations and Electrical Shocks

6.9. Design, Inspection and Restoration

APPENDIX C: DISA FACILITIES ENGINEERING

ELECTRICAL SAFETY PROGRAM

HAW RAISED FLOOR AND CRAH UPGRADE

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Appendices

APPENDIX 1 : DISA Energized Electrical Work Permit APPENDIX 2 : Arc Flash Hazard Identification for Alternating Current (AC) and Direct Current (DC)

Systems APPENDIX 3 : Arc Flash PPE Categories for Alternating Current (AC) Systems APPENDIX 4 : Arc Flash PPE Categories for Direct Current (DC) Systems APPENDIX 5 : Personal Protective Equipment (PPE) APPENDIX 6 : Electrical PPE Worksheet APPENDIX 7 : Shock Protection Approach Boundaries to Exposed Energized Electrical Conductors or

Circuit Parts APPENDIX 8 : Selection of Arc-Rated Clothing and Other PPE When the Incident Energy Analysis

Method Is Used APPENDIX 9 : Figure 3 - Energized Electrical Work Permit Flow Chart

Attachments

ATTACHMENT A Revision Log

ATTACHMENT B Electrical Safety Program Document Proposal/Clarification Form

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1. PURPOSE

This Defense Information Systems Agency (DISA) electrical safety program establishes and documents the safety precautions and responsibilities appropriate to the risk associated with electrical hazards for safe execution of electrical work from 50 to 600 volts of both Direct Current (DC) and nominal Alternating Current (AC). In addition, systems operating at fewer than 50 volts AC or DC where there is increased hazard from electrical arcing, burns, or high current capacity, are also covered. All work within the scope of this program SHALL comply with the facility work practices for general electrical safety and safety-related maintenance activities. Personal Protective Equipment (PPE), energized work and training requirements are addressed in this plan.

2. SCOPE

This program applies to all employees and contractors at the Facility, who plan, perform, supervise and/or execute electrical work, or work in the vicinity of electrical systems.

This electrical safety program is based on the safety-related work practice requirements outlined in Occupational Safety and Health Administration (OSHA) 29 CFR 1910, Safety and Health Standards for General Industry, 29 CFR 1926, Safety and Health Regulations for Construction Industry, the National Fire Protection Association (NFPA) 70, National Electrical Code® (NEC), NFPA 70E®, Standard for Electrical Safety in the Workplace®, and Site-specific requirements.

2.1. ARRANGEMENT

Arrangement of this program is established with Mandatory Rules and Permissive Rules and are defined as follow:

a. Mandatory Rules are actions within this program that are specifically required or prohibited and are identified using the terms SHALL or SHALL NOT.

b. Permissive Rules are actions within this program that are allowed but not a requirement and can be substituted with alternate methods and are identified using the terms Should or Should Not.

3. REFERENCES

The current revision of the reference, including all issued updates, must be followed.

DEFENSE INFORMATION SYSTEMS AGENCY (DISA)

DISA Facilities Engineering Circular

ASTM INTERNATIONAL (ASTM)

ASTM F496 Standard Specification for In-Service Care of Insulating Gloves and Sleeves

NATIONAL FIRE PROTECTION ASSOCIATION (NFPA)

NFPA 70 National Electrical Code®

NFPA 70E Standard for Electrical Safety in the Workplace®

U.S. NATIONAL ARCHIVES AND RECORDS ADMINISTRATION (NARA)

29 CFR 1910 Safety and Health Standards for General Industry

29 CFR 1926 Safety and Health Regulations for Construction

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4. DEFINITIONS AND ACRONYMS

4.1. SHALL/SHALL NOT, SHOULD/SHOULD NOT, AND MAY STATEMENTS

The word SHALL identifies those mandatory requirements or actions. The word Should indicates a recommendation that is based on standards and good safety and business practices. The word may indicates when permission is granted, but the action is neither a recommendation or a requirement. May statements often provide a suggested or possible course of action when a consistent methodology is not required. For emphasis, SHALL/SHALL NOT appear in boldface throughout this document.

4.2. DEFINITIONS

Approved. Acceptable to the authority having jurisdiction.

Arc Flash Boundary. When an arc flash hazard exists, an approach limit from an arc source at which incident energy equals 1.2 cal/cm² (5 J/cm²).

Arc Flash Hazard. A source of possible injury or damage to health associated with the release of energy caused by and electric arc.

Arc Rating. The value attributed to materials that describes their performance to exposure to an electrical arc discharge. The arc rating is expressed in cal/cm² and is derived from the determined value of the arc thermal performance value (ATPV) or energy of breakopen threshold (EBT) (should a material system exhibit a breakopen response below the ATPV value). Arc rating is reported as either ATPV or EBT, whichever is the lower value.

Arc-rated Clothing. Clothing or equipment indicates that is has been tested for exposure to an electrical arc. Flame-resistant clothing without an arc rating has not been tested for exposure to an electric arc. All arc-rated clothing is also flame resistant.

Arc-Resistant Equipment. Equipment designed to withstand the effects of an internal arcing fault and that directs hot gases, plasma, and other products of an arc-flash out of the enclosure so that a worker is not exposed when standing in from of the equipment with all doors and covers closed and latched, reducing the risk of arc-flash exposure. Arc-resistant equipment does not protect the worker when the doors and covers are not properly closed and latched.

ATPV or Arc Thermal Performance Value. As defined in ASTM F1959/F1959M, Standard Test Method for Determining the Arc Rating of Materials for Clothing is the incident energy (cal/cm²) on a material or a multilayer system of materials that results in a 50 percent probability that sufficient heat transfer through the tested specimen is predicted to cause the onset of a second degree skin burn injury based on the Stoll curve.

Authority Having Jurisdiction (AHJ). An organization, office or individual responsible for enforcing the requirements of a code or standard, or for approving equipment, materials, an installation, or procedure.

Circuit Breaker. A device designed to open and close a circuit by nonautomatic means and to open the circuit automatically on a predetermined overcurrent without damage to itself when properly applied within its rating.

De-energized. Free from any electrical connection to a source of potential difference and from electrical charge; not having a potential different from that of the earth. This does not describe a safe condition.

Disconnecting Means. A device, or group of devices, or other means by which the conductors of a circuit can be disconnected from their source of supply.

Enclosed. Surrounded by a case, housing, fence, or wall(s) that prevents persons from unintentionally contacting energized parts.

Electrical Hazard. A dangerous condition such that contact or equipment failure can result in electric shock, arc flash burn, thermal burn, or arc blast injury.

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Electrical Safety Program. A documented system consisting of electrical principles, policies, procedures, and processes that directs activities appropriate for the risk associated with electrical hazards.

Electrical Supervisor (or Electrical Foreman). As used within this document, an Electrical Supervisor or Electrical Foreman SHALL have experience as an electrician, lineman, or engineer.

Energized. Electrically connected to, or is, a source of voltage.

Exposed (as applied to energized electrical conductors or circuit parts). Capable of being inadvertently touched or approached nearer than a safe distance by a person. It is applied to electrical conductors or circuit parts that are not suitably guarded, isolated or insulated.

Fault Current. The amount of current delivered at a point on the system during a short-circuit condition.

Fault Current, Available. The largest amount of current capable of being delivered at a point on the system during a short-circuit condition. The available fault current varies at different locations within the system due to the location of sources and system impedances. Reference Figure 1.

ac or dc supply source

Available fault current

Equipment with a short circuit current rating

Overcurrent protective device with an interrupting rating

Available fault current

Available fault current

Source

OCPD

Load

Equipment

Figure 1: Available Fault Current

Ground Fault. An unintentional, electrically conductive connection between an ungrounded conductor of an electrical circuit and the normally non-current-carrying conductors, metallic enclosures, metallic raceways, metallic equipment, or earth.

Ground-Fault Circuit Interrupter (GFCI). A device intended for the protection of personnel that functions to de-energize a circuit or portion thereof within an established period of time when a current to ground exceeds the values established for a Class A device. Class A GFCI trips when the current to ground is 6 milliamps (mA) or higher and do not trip when the current to ground is less than 4 mA.

Incident Energy. The amount of thermal energy impressed on a surface, a certain distance from the source, generated during an electrical arc event. Incident energy is typically expressed in calories per square centimeter (cal/cm2).

Incident Energy Analysis. A component of an arc flash risk assessment used to predict the incident energy of an arc flash for a specified set of conditions.

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Insulated. Separated from other conducting surfaces by a dielectric (including air space) offering a high resistance to the passage of current.

Interrupting Rating. The highest current at rated voltage that a device is identified to interrupt under standard test conditions.

Labeled. Equipment or materials to which has been attached a label, symbol, or other identifying mark of an organization that is acceptable to the authority having jurisdiction and concerned with product evaluation, that maintains periodic inspection of production of labeled equipment or materials, and by whose labeling the manufacturer indicates compliance with appropriate standards or performance in a specified manner.

Listed. Equipment, materials, or services included in a list published by an organization that is acceptable to the authority having jurisdiction and concerned with evaluation of products or services, that maintains periodic inspection of production of listed equipment or materials or periodic evaluation of services, and whose listing states that either the equipment, material, or service meets appropriate designated standards or has been tested and found suitable for a specified purpose.

Limited Approach Boundary. An approach limit at a distance from an exposed energized electrical conductor or circuit part within which a shock hazard exists.

Nationally Recognized Testing Laboratory. An independent testing laboratory. UL, (Underwriters Laboratory), FM (Factory Mutual), and CSA (Canadian Standards Association) are the main approved testing laboratories that can approve electrical components in accordance with OSHA requirements.

Near. Conditions where contact with exposed energized components is possible by slipping, tripping, falling, actions of others, or inadvertent action of reasonable probability. For electrical panels, with exposed electrical components at 50V or greater, breaking the plane of the panel with any tool (except insulated meter probes) or body part is considered “near.”

Permanent GFCI. A GFCI breaker installed in a power panel, or an outlet type GFCI installed in an outlet box. The GFCI will have a gang type configuration, meant to be installed in an outlet box.

Portable GFCI. A GFCI listed and identified for portable use, and usually has a pigtail on one or both of the male and female connectors. The GFCI is commonly enclosed in a molded case.

Qualified Person. 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 the hazards and reduce the associated risk.

Raceway. An enclosed channel of metal or nonmetallic materials designed expressly for holding wires, cables, or bus bars, with additional functions as permitted in the National Electrical Code. Raceways include, but are not limited to, rigid metal conduit, rigid nonmetallic conduit, intermediate metal conduit, liquid-tight flexible conduit, flexible metallic tubing, flexible metal conduit, electrical nonmetallic tubing, electrical metallic tubing, underfloor raceways, cellular concrete floor raceways, cellular metal floor raceways, surface raceways, wireways, and busways.

Restricted Approach Boundary. An approach limit at a distance from an exposed energized electrical conductor or circuit part within which there is an increased likelihood of electric shock, due to electrical arc-over combined with inadvertent movement.

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Any point on an exposed, energized electrical conductor or circuit part

Restricted approach boundary

Limited approach boundary

Arc flash boundary

Limited space

Restricted space

Figure 2: Limits of Approach

Risk. A combination of the likelihood of occurrence of injury or damage to health and the severity of injury or damage to health that results from a hazard.

Risk Assessment. An overall process that identifies hazards, estimates the likelihood of occurrence of injury or damage to health, estimates the potential severity of injury or damage to health, and determines if protective measures are required.

Shock Hazard. A source of possible injury or damage to health associated with current through the body caused by contact or approach to energized electrical conductors or circuit parts.

Short-Circuit Current Rating. The prospective symmetrical fault current at a nominal voltage to which an apparatus or system is able to be connected without sustaining damage exceeding defined acceptance criteria.

Testing, Meter. Meter operational tests made before and after measuring a circuit to prove de energization must meet several criteria. Tests and the actual measurement must be on like sources, such as AC volts, DC volts, etc., for both autoranging and set range type meters. In addition, set range meters must have the operational test and actual voltage test done on the same range. For example, checking a 120V control circuit or outlet would be an acceptable operational test for a meter being used to test 480V, for most meters, as long as it gives a readable indication. Testing at the lower voltage is preferred, as it subjects the electrical worker to less risk. For voltages up through 600V, an operational test is required before making the actual voltage test for de-energization. For voltages over 600V, an operational test is required both before and after the voltage test for de-energization. Time, and movement of the meter between operational tests and the actual voltage tests should be minimized as much as possible.

Trained and Qualified Electrical Worker. A person with a demonstrated knowledge of the operation, installation and construction of electrical conductors, systems and circuit parts to be worked on, and a knowledge of the hazards involved. Determination of this designation (trained and qualified electrical worker) SHALL be the responsibility of an electrical supervisor with input from the employee. For new employees, the designation of Trained and Qualified Electrical Worker SHALL be determined by an electrical supervisor based on the following:

Observed performance under well controlled and supervised conditions.

Input from the employee.

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Voltage (of a Circuit). The greatest root-mean-square (rms) (effective) difference of potential between any two conductors of the circuit concerned.

Working Distance. The distance between a person’s face and chest area and a prospective arc source.

4.3. ACRONYMS

AC Alternating Current

ASTM American Society for Testing and Materials

CPR Cardiopulmonary Resuscitation

DC Direct Current

DoD Department of Defense

GFCI Ground Fault Circuit Interrupter

IRT Infrared Thermography

LO/TO Lock Out/Tag Out

NEC National Electrical Code

NFPA National Fire Protection Association

OSHA Occupational Safety & Health Administration

PPE Personal Protective Equipment

UL Underwriters’ Laboratory

5. RESPONSIBILITIES

5.1. SUPERVISION/MANAGEMENT

Supervision/management SHALL ensure that employees assigned to perform electrical work in the facility and are exposed to an electrical hazard are trained and qualified to safely perform the work. Per NFPA definition, 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 the hazards and reduce the associated risk”.¹ Training SHALL include review and understanding of this electrical safety program and awareness of potential electrical hazards within the facility. Employees SHALL be required to maintain self-discipline and awareness of all facility modifications that introduce electrical hazards. Tools and PPE required for safe performance of work SHALL be stored and maintained according to manufacturer’s recommendations at all times. Supervision/ management SHALL ensure that work involving electrical conductors, systems and circuit parts is de-energized and locked out prior to starting any work exposing the employee to an electrical hazard. If energized electrical work is unavoidable, supervision/management SHALL justify and approve the work activity. A DISA Energized Electrical Work Permit (see Appendix 1) SHALL be in place for every job involving energized electrical work, as defined in section 6.5, unless under exception as identified in section 6.5.

5.2. EMPLOYEES

All workers who perform electrical work in the Facility must comply with the PPE and safe work requirements described by this plan. DISA SHALL notify all contractors performing electrical work in the Facility of the known hazards covered by this electrical safety program. All necessary information required for the contractor to perform their duties SHALL be made available to accomplish the necessary safety evaluations.

In the event that violations of this electrical safety program are observed by the facility or knowledgeable representatives, notification SHALL be made to the employee, their employer and through appropriate communication channels.

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5.3. CONTRACTORS

The contractor’s employer SHALL ensure that all hazards associated with assigned work are reviewed and communicated to the contractor performing the work. The contractor’s employer SHALL ensure that all workers who perform electrical work in the Facility must comply with the safe work requirements described by this plan at a minimum. The contractor’s company specific safety requirement SHALL NOT subtract from this plan. The contractor SHALL immediately report any unique or unanticipated electrical hazards encountered during the performance of their work in the Facility to the identified DISA Point of Contact familiar with the work. Corrective measures taken for any discovered electrical hazards SHALL be communicated to DISA for correction to prevent future occurrence.

6. REQUIREMENTS

This section defines the minimum safety requirements for documenting and performing work on or around electrical equipment and circuits at the Facility. The requirements include safety requirements of 29 CFR 1910, Safety and Health Standards for General Industry, 29 CFR 1926, Safety and Health Regulations for Construction, NFPA 70® National Electrical Code®, NFPA 70B Recommended Practice for Electrical Equipment Maintenance, and NFPA 70E®, Electrical Safety in the Workplace®. Electrical work SHALL be performed in the Facility by trained and qualified workers knowledgeable of the risk associated with electrical hazards.

6.1. GENERAL SAFETY REQUIREMENTS

All equipment and circuits SHALL be treated as energized until the equipment or circuit has been tested to verify no voltage or has been physically verified to be isolated, disconnect or physically separated from the power source with no ability to be re-connected. Lock Out/Tag Out (LO/TO) methods SHALL be used to provide indication of de-energization.

Items such as badge holders, watches, jewelry, tools, steel tape measures, body piercings and other conductive materials SHALL NOT be worn within the restricted approach boundary or placed on or around energized electrical equipment or circuits.

When working on or near exposed energized parts, approved electrical safety equipment and PPE SHALL be used. Some tasks such as operating high power switches while energized may require safety equipment even without exposed energized electrical components (Reference 6.8, and Appendix 3). Listed below are some examples of electrical safety equipment and alerting techniques that may be used:

Wear only approved protective clothing, or arc-rated (AR). See Section 6.8.1.

Appropriate class of rubber insulating gloves, and leather protectors. See Section 6.8.2.

Rubber insulating blankets and other approved insulating materials.

Voltage testers

Insulated fuse pullers.

Barricades and signs to alert and keep away non-job related, unprotected or unqualified personnel.

Electronic tools to locate wiring hidden in floors or walls.

Ground penetrating radar, to locate hidden cables or conduit

Infrared thermography (IRT), to identify potential overheated wires and connections.

Ultrasonic inspection, to detect ultra-high frequency emissions for potential problems

Control circuit devices, such as push buttons, selector switches, interlocks, building automation or remotely operated systems, SHALL NOT be used as the primary or sole means of safety isolation.

Ensure there is adequate lighting at job site. Utilize temporary lighting, if necessary.

Only non-conductive ladders are approved for electrical work per OSHA regulation 29 CFR 1926.951(c)(1).

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Ground fault indications and alarms on equipment SHALL be reported promptly to supervision/management, and addressed as soon as practical.

Capacitors SHALL be discharged and high capacitance elements SHALL be short-circuited and grounded.

Be aware of the possibility of multiple power sources to equipment, or in conduit. Interlocks between equipment and transfer switches are a likely situation to expect multiple power sources.

Before coming in direct contact with equipment and/or circuits thought to be de- energized, the following SHALL apply:

LO/TO protection or circuit disconnection is completed, as required.

Voltage tester SHALL be a contact type analog or digital multimeter, except as noted below, checked for correct range, then used to test equipment and/or circuits to be worked. Prior to testing of equipment and/or circuits, the voltage tester SHALL be operationally tested on a known energized source for response and to ensure operability. “Tic tracers”, “wiggies” or proximity type devices are not adequate for this test. The before and after voltage tests are still required.

A determination SHALL be made as to the use of grounding device(s) or insulated tools and safety equipment before coming in direct contact with equipment or circuits. This includes de-energized circuits and equipment that needs to be checked for stored or induced electrical energy.

Personnel SHALL NOT enter spaces containing exposed energized parts, unless sufficient illumination is provided to enable safe work.

Personnel required to work in close quarters without adequate work space SHALL use protective shields, barriers or insulating materials as necessary.

Determine the scope of a pre-job briefing after consideration of the following:

Job plan

Voltage(s)

Circuit loads

Accessibility

Complexity of job

Need for reference drawings, utility searches

Proximity to energized circuits or equipment

Understanding of distribution assignment and impacts to mission

6.2. CIRCUIT BREAKERS AND SWITCHES

When a protective device such as a circuit breaker trips or fails, operations personnel responsibilities are to:

Inform supervision/management and the point of contact for the equipment or system.

Attempt to safely determine the cause of the trip or failure. An electrician SHALL be consulted if the cause is not apparent, or 240V and above is involved.

Reset of the device one time is permitted if authorized by the Facility Manager or designee. Personnel who are not Trained and Qualified Electrical Workers SHALL NOT reset protective devices.

A protective device SHALL NOT be reset a second time unless the cause of the trip is understood and corrected, and has been authorized by the facility leadership.

Resetting protective devices may require arc flash protection PPE. Reference 6.8.1, and Appendix 3.

All actions taken in association with the tripped or failed device SHALL be documented and reported to facility leadership, as appropriate.

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6.3. INTERLOCKS

Only trained and qualified electrical workers, with approval of the site Facility Manager or his/her designee, may defeat an electrical safety interlock, or a mechanical interlock that restricts access to electrical equipment. The interlock SHALL be returned to its standard position at the completion of work for which it was defeated, unless directed otherwise in writing. Be aware of multiple power sources when working on electrical interlocks, especially between different pieces of equipment.

6.4. GROUND FAULT CIRCUIT INTERRUPTERS (GFCIS)

GFCI protection SHALL be provided for all 125 volt (nominal), single-phase 15, 20 and 30 amp receptacle outlets supplying power to portable hand held equipment used by employees in all outdoor applications, in wet or damp locations, and where workers are likely to be well grounded (i.e. mechanical rooms, electrical rooms, etc.) in accordance with 2020 NFPA 70, Article 590.6.

6.5. ENERGIZED ELECTRICAL WORK

Energized electrical work is defined as work performed on or near energized electrical conductors and circuit parts operating at 50 volts or greater. It is also where less than 50 volts is present and increased potential exposure to electrical burn or explosion hazards exist due to electrical arcing, as well as testing of a system thought to be de- energized, but not yet proven to be. (for example, a LO/TO effectiveness check) See “near” in Appendix 1.

Every effort SHALL be made to establish an electrically safe work condition by de-energizing electrical conductors, systems and circuit parts prior to work. The Facility LO/TO program SHALL be used to de-energize any control systems and equipment. Electrical conductors and circuit parts SHALL be de-energized before the employee works within the Limited Approach Boundary of those conductors or parts, unless the individual requesting the work can demonstrate that one of the criteria listed in section 6.5.1 apply. Energized electrical conductors and circuit parts that operate at less than 50 volts to ground need not be de-energized where the capacity of the source and any overcurrent protection between the energy source and the worker are considered and it is determined that there is no increased exposure to electrical burn or explosion from electrical arcing. An example of exposure to burn or arcing would be a UPS battery bank capable of a sustained arc of several hundred amps for several seconds, with no overcurrent protection between the batteries and the work area.

Work on, with, or near megger and high potential (hi-pot) testers, and electric fencing are not considered energized work, due to the extremely low current involved, although contact should be avoided due to startle reaction possibility. For other high voltage low current equipment, the following guidelines apply. If the current is above 5 milli-ampere (ma), or the energy above 10 joules, then energized electrical rules apply, including LO/TO, and the use of insulated tools rated for the voltage, and dielectric gloves per Section 6.8.2.

If the current is between 0.5 and 5 milliamps (ma), or the energy is between 0.25 and 10 joules, then startle reaction is possible, and should be mitigated by the use of insulated gloves and tools, avoiding contact, or removing or guarding objects likely to cause injury if a startle reaction occurs. Current and energy levels below 0.5ma, and 0.25 joules are of little concern.

Electrical conductors and circuit parts SHALL be considered energized unless they are one of the following.

Disconnected or a physical air gap created by cutting back the wires so they can’t be re-connected without splicing, labeled, and verified to be de-energized.

Isolated by a LO/TO and positively determined to be de-energized.

In both cases, a test to verify no voltage SHALL be made by a trained and qualified electrical worker. The voltage test SHALL be with a contact type multi-meter, or Volt-Ohm-Meter rated for the circuit being tested.

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CAUTION: “Tic tracers”, “wiggies”, or proximity type testers are not acceptable for voltage tests.

The meter must be tested on a known source before making the de-energization measurement, as well as after if the voltage is over 600v. See “Meter Testing” in Appendix 1 for more details.

NOTE: Neutral conductors may show little or no voltage indication even though they may be carrying significant current, since the neutral is grounded at the power panel or source.

Measurement with a clamp-on ammeter is recommended.

After the de-energization or effectiveness check with a contact type meter, other types of voltage indicators may also be used for testing, or subsequent checks for voltage. Before starting work, preliminary inspections and tests SHALL be conducted by a trained and qualified electrical worker to determine the actual condition and state of energization of the electrical conductors and circuit parts. Only qualified electrical workers SHALL be allowed to move energized wires or cables that are part of fixed building wiring. Physical strain SHALL NOT be placed on wires, cables or raceway that is energized or contains energized conductors, or that will be re-energized.

Energized electrical work approval authority and responsibility is vested in the site Facility Manager or his/her designee(s). All documentation generated by this program SHALL be retained for the purpose of review and audit by DISA Facilities Engineering.

An electrical supervisor or foreman (See Appendix 1 definition) or site facilities representative SHALL be present during all energized electrical work, at nominal 480V, to directly oversee the work, compensatory safety measures and PPE. A site facilities representative Should be present for energized work at lower voltages.

Authorized written justification for energized work, using the DISA Energized Electrical Work Permit, Appendix 1, SHALL be included as a part of the documentation for performance of energized electrical work.

This justification Should have input from the electrical craft. Where less than 50 volts is present but increased potential exposure to electrical burn or explosion exists due to electrical arcing and/or high current capacity, the task SHALL be considered energized work. An example would be a large UPS battery bank capable of a sustained arc of several hundred amps for several seconds with no overcurrent protection between the batteries and the work location. See definition of “near” in Appendix 1.

Temporary guards, isolation or insulation barriers, such as shields, insulating blankets or tape SHALL be used whenever reasonably possible to protect the worker from the possibility of shock. It is important that the protection be securely fastened in place, so that it cannot be accidentally dislodged or removed.

Anyone performing authorized energized electrical work SHALL have the area around the work cordoned off or barricaded, except as noted below, so that disturbances, distraction, accidental bumping or other physical contact, cannot occur. Bystanders, passers-by, and unprotected, unqualified co-workers SHALL be kept at a specified minimum distance, which is the greater of the Arc Flash Protection, or the Limited Approach Boundary, by these barricades. Conductive barricades SHALL NOT be used it could increase the likelihood of exposure to an electrical hazard. Where the arc flash boundary is greater than the limited approach boundary, barricades SHALL NOT be placed closer than the arc flash boundary. Qualified personnel SHALL NOT get closer to energized electrical components than the Arc Flash Boundary, unless wearing PPE for Arc Flash Protection. If these barricades do not provide sufficient warning, a person Should be posted to prevent unprotected personnel from entering the area.

An exception to the barricading requirement is allowed for continuously attended LO/TO configuration investigations, LO/TO installation, verification and effectiveness checks, not to exceed 480V nominal, as long as the exposure does not exceed 5 minutes. During this time the Limited Approach and Arc Flash Protection Boundaries required by NFPA 70E must still be enforced by an alternate means. If after 5 minutes, the energized electrical work is not complete, barricading or other alerting techniques must be set up as required in the preceding paragraph.

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The second person, when required by the two-person rule (see section 6.6), may only watch the person performing the energized electrical work, and not enforce the boundary. This boundary distance is the greater of the Shock Protection Approach Boundaries to Exposed Energized Electrical Conductors or Circuit Parts, given in the 2021 edition of NFPA 70E, Article 130, Table 130.4(E)(a) for Alternating-Current Systems and Table 130.4(E)(b) for Direct-Current Voltage Systems.

Bench type work in an electrical shop area is exempted from the barricade or cordoning off requirements, and unprotected personnel access Should be administratively controlled.

Conductors SHALL NOT be installed in, or removed from, raceways containing energized or potentially energized conductors. When conductors are removed from or installed in a raceway with all circuits de-energized (disconnected or under LO/TO), all conductors Should be meggered at their rated voltage before re-energizing any of the conductors, due to the possibility of insulation damage.

Racking in or installing breakers or motor control center “buckets” in or out of an energized MCC or switchgear, or operating switches or breakers on energized switchgear SHALL be considered energized work. The breaker being racked in or installed SHALL be “open” and any power or control wiring that would be subject to strain or damage must be disconnected. Beware that some large breakers have a “test” position when racked out, that disconnects the main power, but leaves control circuits energized for testing.

6.5.1. Energized Electrical Work Criteria

Work on energized electrical conductors and circuit parts may only be approved and performed for one of the following reasons:

For testing or calibration, when tests cannot be done with the circuit or equipment de-energized.

For troubleshooting, when the problem cannot be identified unless the circuit or equipment is energized. Where possible the equipment SHALL be de-energized while adjustments are made and then re-energized.

When the removal of the power could reasonably be expected to introduce additional or increased hazards, is not feasible due to equipment design or operating limitations, or poses a greater risk to mission critical operations than working on the exposed energized circuits or equipment. In such cases, preference SHALL be given to stopping work, initiating compensatory actions for the work to be done and de-energizing the work area.

NOTE: LOTO effectiveness checks, or pre-LO/TO verifications of correct isolation devices, which include voltage testing, and may include cycling of the isolation device, continuity checks, signal tracing or other methods, are exempt from the energized electrical work permit requirement, as long as no moving, de- terminating or re-terminating of wiring is required. All PPE requirements SHALL apply.

An energized electrical work permit may be repetitively used when incorporated into work that is routine, and not subject to change from job to job.

6.5.2. Energized Electrical Work Permit Exemption

Meter readings, or testing, without moving wires or terminals, and using insulated probes, are allowed without an energized electrical work permit per 2021 NFPA 70E, Article 130.2(C). Insulating gloves and other PPE as required by sections 6.8.1 and 6.8.2 SHALL be worn when performing energized work, regardless of whether a permit is required. All other work, troubleshooting, measurements or testing on or near energized electrical conductors and circuit parts, or equipment operating at greater than 50 volts SHALL be considered energized work and follow the requirements of section 6.5.1.

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NOTE: Energized electrical conductors and circuit parts can be observed and assessed by a qualified individual, as long as a safe distance is maintained. This distance is defined as being outside the Arc Flash Boundary for unprotected, qualified workers. The Arc Flash Boundary SHALL NOT be breached by any uninsulated tool or unprotected body part, and requires an energized electrical work permit, except as previously noted for voltage measurements. Protected qualified employees may work inside of the Arc Flash Boundary from energized electrical parts. Unqualified and unprotected personnel must remain outside of the Limited Approach Boundary, and Arc Flash Boundary, whichever is greater.

Reference sections 6.5, and 6.8 of this chapter, Figure 2 and the definition of “near”, “Arc Flash Boundary”, and “Limited Approach Boundary” in Appendix 1.

For telecommunications workers, energized work approval and presence of an electrical supervisor or foreman or site facilities representative is not required, if ALL of the following conditions are met.

(1) Only analog or digital communications signals (including “ringer” signals) and no other electrical hazards exist, that are not under a LO/TO.

(2) Energy release is not “unexpected”, as used in 29CFR1910.147(a)(1)(I). In other words, the worker is handling the conductors as if he/she expects them to be energized.

(3) Workers are isolated from ground, grounded objects, or wet locations by insulating gloves, mats or blankets rated for the voltage involved, and inspected before each use.

(4) Insulated tools are used, in good condition, and inspected before each use.

6.6. TWO-PERSON RULE

The two-person rule requires the presence of two trained and qualified electrical workers when working on or in close proximity to exposed energized electrical conductors and circuit parts. The two-person rule requires that the first person performs the work while the second person stands by to render assistance, or to summon help for the first person, in the event he/she is inadvertently shocked while performing the work.

The second person SHALL be qualified in cardiopulmonary resuscitation (CPR) and know the location of the isolation device(s) for the equipment being worked on. The second person SHALL NOT be assigned to additional duties or tasks while the energized electrical work is being performed. Isolators and verifiers required to work together due to configuration, or other multiple member crews may alternate being the worker or the second person, as long as the second person has no other duties at the time they are acting as the second person. Alternating two electricians may be used to advantage when performing work that requires both wire color recognition, and arc flash protection requiring when the green face shield is part of the PPE. One electrician may wear a clear face shield, and PPE for low risk work, identify or set up work for the other electrician who wears the green face shield and heavier PPE for higher risk work. They may alternate in their duties as worker and second person as required, to perform the work they are protected for.

6.7. TRAINING

The training requirements contained in this Section apply to workers exposed to an electrical hazard that is not reduced to a safe level while working on or near energized electrical conductors and circuit parts as a part of their job assignment. Qualified workers SHALL be trained in safety related work practices, emergency response procedures, and other requirements that pertain to their respective job assignments. Employees SHALL NOT be permitted to work in areas where they are likely to encounter an electrical hazard unless they have been trained to recognize and avoid these hazards.

6.7.1. Emergency Actions

Employees exposed to shock hazards, as part of their job assignment, SHALL be trained in methods of release of victims from contact with exposed energized electrical conductors or circuit parts. Employees SHALL be regularly instructed in methods of first aid and emergency response procedures, such as approved methods of resuscitation, if their duties warrant such training. Training of employees in approved

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UNCLASSIFIED Page 15 of 34 methods of resuscitation, including cardiopulmonary resuscitation, SHALL be provided in compliance with certification periods.

6.7.2. Contractors

Contractors who employ apprentice and licensed electricians SHALL be briefed on the Facility specific electrical safety requirements contained in this Program. In addition, written documentation Should be provided by the contractor verifying that the electrician(s) have successfully completed training in accordance with 29 CFR 1910.332, Training.

6.8. PERSONAL PROTECTIVE EQUIPMENT

6.8.1. Protective Apparel and Equipment

When working on or near exposed electrical conductors or circuit parts that are or might become energized, work practices SHALL be used to protect employees who might be exposed to the electrical hazards involved. Such work practices SHALL protect employees from arc flash and from contact with energized electrical conductors and circuit parts directly, with any part of the body, or indirectly through some other conductive object. The work practices used SHALL be suitable for the conditions under which the work is to be performed and for the voltage level of the energized electrical conductors and circuit parts.

Employees working in areas where there are electrical hazards SHALL use protective equipment that is designed and constructed for the specific part of the body to be protected, and for the work to be performed.

Some examples of Personal Protective Equipment (PPE) are listed below:

Hard hat (non-conductive with flame resistant liner)

Rubber insulating gloves rated for the voltage being worked

Leather protectors for insulating gloves

Arc-rated shirt, pants and coveralls

Arc-rated double layer switching hood

Safety glasses, goggles or face shield

Hearing protection

Voltage rated mats, sleeves, or blankets

Voltage rated tools

Leather or dielectric work shoes

Where it has been determined that work will be performed in areas where there are electrical hazards, Arc Rated (AR) clothing and Personal Protective Equipment (PPE) SHALL be used by the employee when working within the Restricted Approach Boundary (See definition in Appendix 1). The selection of PPE SHALL be based upon the incident energy exposure (in calories per square centimeter) associated with the specific task. To determine the incident energy exposure (Arc Flash PPE Category) of the task, the worker Should first review applicable Arc Flash Labeling on the system. If no current applicable labeling is applied, the method for determining appropriate Arc Flash PPE SHALL be determined by either, but not both, the Incident Energy Analysis Method (2021 NFPA 70E, Table 130.5(G)) or the Arc Flash PPE Categories Method (2021 NFPA 70E, Article 130.7(C)(15)). If the Incident Energy Analysis Method is used, the resultant arc flash PPE category from 2021 NFPA 70E, Table 130.7(C)(15)(a) SHALL NOT be permitted. The Arc Flash Incident Energy Analysis Method SHALL provide an incident energy value in J/cm² (cal/cm²). Arc Rated PPE SHALL be chosen based on this energy value and SHALL NOT have a rating less than the calculated value. Arc-rated clothing and other PPE requirements SHALL be permitted to be used with the incident energy analysis method of based on 2021 NFPA 70E, Table 130.5(G) located in Appendix 8.

If no analysis has been performed for the identified exposed energized electrical conductors and circuit parts, the Arc Flash PPE Categories Method is allowed. The work Should first determine if Arc Flash PPE is required. Reference Appendix 2 Arc Flash Hazard Identification for Alternating Current (ac) and Direct

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UNCLASSIFIED Page 16 of 34 current (dc) Systems. Where Appendix 2 indicates that Arc Flash PPE is not required, an Arc Flash is not likely to occur. Where Arc Flash PPE is required, Appendix 3 SHALL be used to determine the Arc Flash PPE category for alternating current (ac) equipment and Appendix 4 for direct current (dc) equipment.

If the planned task is not listed in Appendix 3, then a complete Arc Flash Risk Assessment must be performed when possible, in accordance with Article 130.5 and Annex F of 2021 NFPA 70E. The Arc Flash Risk Assessment will determine appropriate safety-related work practices, the Arc Flash Boundary distance and the necessary PPE to be used within the Arc Flash Boundary. This analysis must be performed by an electrical engineer, as analysis of fault currents is required. The Arc Flash Risk Assessment SHALL be updated for any major electrical modifications and SHALL be reviewed periodically not to exceed 5 years.

The results of the assessment SHALL be documented and retained for reference.

When the incident energy exposure (Arc Flash PPE Category) has been determined utilizing the Arc Flash PPE Categories Method, the recommended PPE can be found by referring to Appendix 5, Personal Protective Equipment (PPE). If Appendix 3 was used, select the chart that corresponds to the Arc Flash PPE Category for the task. If an Arc Flash Risk Assessment was performed, select the lowest Hazard Category Chart that bounds the calculated incident energy exposure. Appendix 6, Electrical PPE Worksheet, SHALL be used to document the incident energy exposure and determine the final PPE requirements for the task.

The appropriate representative SHALL evaluate the recommended PPE by considering any special circumstances that may influence the final PPE selection. This evaluation SHALL be conducted jointly with the employees who will perform the task. Examples of factors that may influence the decision include, but are not limited to:

The need to distinguish colors accurately may make it impossible to wear a tinted face shield or switching hood during all phases of the task.

The need for manual dexterity may make it desirable to reduce the number of gloves being worn.

Working on a ladder may increase the risk of a fall while wearing a switching hood.

Wearing a switching hood may create an unacceptable heat stress situation.

Awkward positions or cramped spaces may require modifications to the PPE being worn.

The appropriate representative SHALL document any mitigating factors considered in making the final PPE selection and indicate the PPE required for the task on Appendix 1. In addition, the appropriate representative SHALL document any special instructions for using the PPE on Appendix 1. Special instructions might be required when the specified PPE needs to be modified (or substitutions made) for some of the work steps included in the task. For example, the tinted face shield may need to be removed or replaced with a clear face shield for those steps that require color definition. The final PPE selected Should result in the least interference with the task, but still provide the necessary protection, to the extent possible.

The work method, location, and task may influence the protective equipment selected.

If the final PPE selected for the task is less than the PPE recommended in the Appendix 5 table, then document the reductions on Appendix 6. The Facility Manager or his/her designee(s) must approve the final PPE selection if it is less than the PPE recommended in the Appendix 5 table and SHALL indicate approval by signing the Energized Electrical Work Permit.

Additional copies of Appendix 6 SHALL be used for each energized work task that results in a different Hazard Category.