Att 11 - 64_Electrical Safety_010325.pdf

NIST S 7101.64, Ver. 1a (Uncontrolled Copy in Print) Page 1 of 81

ELECTRICAL SAFETY 1

NIST S 7101.64 3

Approval Date: 09/19/2024 4 Effective Date1: TBD 5

CONTENTS 6

1. PURPOSE ................................................................................................................................ 2 7

2. BACKGROUND ..................................................................................................................... 2 8

3. APPLICABILITY ................................................................................................................... 3 9

4. REFERENCES ........................................................................................................................ 4 10

5. APPLICABLE NIST DIRECTIVES ....................................................................................... 5 11

6. REQUIREMENTS .................................................................................................................. 6 12

a. General Electrical Safety Requirements for Any Workspace or Work Activity ................. 6 13

b. Provision of Temporary Electrical Power.......................................................................... 12 14

c. Work on Electrical, Electronic, and Electro-Mechanical Equipment and Circuits ........... 13 15

d. Establishment of an Electrically Safe Working Condition, i.e., achieving Mode 0 ......... 31 16

e. Provision of an Energized Electrical Work Permit ............................................................ 33 17

f. Additional Requirements for Energized Electrical Work Greater than 600 V (High-18 Voltage) ..................................................................................................................................... 36 19

g. Establishment of Boundaries using Barricades.................................................................. 40 20

h. Employment of a Two-Person Work Rule......................................................................... 41 21

i. Personal Protective Equipment (PPE) and Other Protective Equipment ........................... 42 22

j. Listed or Labeled Electrical and Electronic Equipment .................................................... 45 23

k. Electrical Distribution Systems.......................................................................................... 48 24

l. Training .............................................................................................................................. 54 25

m. Electrical Incidents and Investigations ........................................................................... 56 26

n. Annual Audits .................................................................................................................... 57 27

o. Records Required by this Suborder ................................................................................... 57 28

7. ACRONYMS......................................................................................................................... 66 29

8. RESPONSIBILITIES ............................................................................................................ 67 30

9. AUTHORITIES ..................................................................................................................... 69 31

1 Please see Appendix A for revision history.

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10. DIRECTIVE OWNER ....................................................................................................... 69 32

11. APPENDICES ................................................................................................................... 69 33

1. PURPOSE 35

The purpose of this suborder is to establish the requirements and associated roles and 36 responsibilities to protect NIST staff from exposure to electrical hazards while working on or 37 around electrical, electronic, and electro-mechanical equipment and circuits. This suborder 38 supersedes NIST N 7101.64: Electrical Safety upon its effective date. 39

2. BACKGROUND 42

NIST workspaces vary from research laboratories to office environments to industrial-like 43 settings. In addition, the type of work performed in these spaces varies greatly which yields 44 the full spectrum of electrical safety hazards ranging from a mild electrical shock or burn to 45 arc flash or electrocution. While some electrical safety requirements to ensure a safe 46 workspace are straightforward, e.g., see Section 6.a, the complexity of some electrical safety 47 hazards observed at NIST presents a challenge to communicating the necessary requirements 48 effectively and efficiently. For those cases, this suborder provides a formal approach to 49 identifying general safe work practices related to the characteristics of the electrical hazards 50 NIST staff may encounter as they perform their official duties. To facilitate this effort, NIST 51 adopted a best practice developed by the Department of Energy (DOE)2 of using various 52 parameters to make an electrical hazard assessment for the work to be performed: 53

• Electrical hazard categories – Five broad categories based on dissimilar electrical 55 sources; 56

• Electrical hazard classes – Four classes derived from possible injury mechanisms that 57 could occur when workers encounter varying levels of energy from different sources; 58 and 59

• Modes of electrical work – Four different modes focused on the type of work to be 60 performed. 61

These parameters are discussed in detail in Appendix B. Using this information collectively 63 throughout Section 6 allows NIST staff to correctly identify the minimum applicable 64 requirements such as control measures, type of personal protective equipment (PPE), and 65 training qualifications requirements for a given scenario. 66 The requirements of this suborder do not supersede the requirements for conducting a hazard 68 assessment per NIST S 7101.20 Hazard Review. 69

2 DOE Handbook 1092.

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3. APPLICABILITY 70

a. The requirements of this suborder apply to NIST employees and covered associates who may 71 be exposed to electrical hazards while performing work on electrical, electronic, and electro-72 mechanical equipment or circuits at NIST worksites. 73

NOTE: Some requirements may not be applicable at worksites not under NIST 75 jurisdiction. For questions or concerns, please contact the NIST Authority Having 76 Jurisdiction (AHJ) regarding applicability of a requirement. 77

b. The requirements of this suborder apply to NIST non-R&D contractors who may be exposed 79 to electrical hazards while performing work on electrical, electronic, and electro-mechanical 80 equipment or circuits at NIST worksites. 81

(1) The non-R&D contractor is required to exchange their electrical safety program with 83

NIST if they will be engaged in work covered by this suborder. 84

(2) The NIST Contracting Officer's Representative (COR) shall ensure NIST identifies 86 requirements that are applicable to the non-R&D contractor and ensure the non-R&D 87 contractor follows the NIST requirements. 88

c. The requirements in this document apply to the development, operation, and maintenance of 90 electrical, electronic, and electro-mechanical equipment and circuits including design of 91 future systems and equipment. Research that includes the development and use of 92 specialized electrical, electronic, and electro-mechanical equipment for specific projects or in 93 support of those projects shall comply with the requirements of this suborder to the extent 94 feasible. In cases where it is not feasible to comply with one or more of these requirements, 95 a request for variance3 shall be submitted for review and approval to the AHJ. 96

d. This suborder does not specify the requirements for the control of hazardous energy 98 (lockout/tagout - LOTO). All lockout/tagout operations, including lockout/tagout of live 99 electrical conductors, must comply with the requirements of NIST S 7101.56. In general, 100 workers should assume that all electrical conductors and circuit parts are energized until they 101 have been de-energized, verified to have zero volts, locked, and tagged in accordance with 102 the approved LOTO process. However, where required, additional requirements of this 103 suborder must be met during all electrical work, including electrical lockout/tagout (i.e., 104 Mode 1 electrical work as discussed in Appendix B) and verification of zero voltage. 105

3 Please see NIST PR 7101.00: Procedure for Requesting Safety-Related Variances and Waivers for details regarding the variance process.

NIST S 7101.64, Ver. 1a (Uncontrolled Copy in Print) Page 4 of 81

4. REFERENCES 109

a. ANSI Z87.1, Practice for Occupational and Educational Eye and Face Protection, latest 110 edition. 111

b. ANSI Z89.1, Requirements for Protective Headwear for Industrial Workers, latest edition. 113

c. ASTM D120, Standard Specification for Rubber Insulating Gloves, latest edition. 115

d. ASTM D178; Standard Specification for Rubber Insulating Matting, latest edition. 117

e. ASTM D1048 Standard Specification for Rubber Insulating Blankets, latest edition. 119

f. ASTM D1049; Standard Specification for Rubber Insulating Covers, latest edition. 121

g. ASTM D1050; Standard Specification for Rubber Insulating Line Hose, latest edition. 123

h. ASTM D1051; Standard Specification for Rubber Insulating Sleeves, latest edition. 125

i. ASTM F696, Standard Specification for Leather Protectors for Rubber Insulating Gloves and 127

Mittens, latest edition. 128

j. ASTM F711, Standard Specification for Fiberglass-Reinforced Plastic (FRP) Rod and Tube 130 Used in Live Line Tools, latest edition. 131

k. ASTM F1505, Standard Specification for Insulated and Insulating Hand Tools, latest edition. 133

l. ASTM F1506, Standard Performance Specification for Flame Resistant and Arc Rated 135

Textile Materials for Wearing Apparel for Use by Electrical Workers Exposed to Momentary 136 Electric Arc and Related Thermal Hazards, latest edition. 137

m. ASTM F2413, Standard Specification for Performance Requirements for Protective (Safety) 139

Toe Cap Footwear. 140

n. ASTM F2178 Standard Specification for Arc Rated Eye or Face Protective Products. 142

o. Department of Energy Handbook 1092, “Handbook for Electrical Safety” (DOE-HDBK-144 1092). https://www.standards.doe.gov/standards-documents/1000/1092-BHdbk-145 2013/@@images/file. 146 http://www.astm.org/Standards/D120.htm http://www.astm.org/Standards/F696.htm http://www.astm.org/Standards/F696.htm https://www.astm.org/f0711-17.html https://www.astm.org/f0711-17.html https://www.astm.org/f1505-16r21.html http://compass.astm.org/EDIT/html_annot.cgi?F1506+15 http://compass.astm.org/EDIT/html_annot.cgi?F1506+15 http://compass.astm.org/EDIT/html_annot.cgi?F1506+15 https://www.astm.org/f2413-18.html https://www.astm.org/f2413-18.html https://www.standards.doe.gov/standards-documents/1000/1092-BHdbk-2013/@@images/file https://www.standards.doe.gov/standards-documents/1000/1092-BHdbk-2013/@@images/file

NIST S 7101.64, Ver. 1a (Uncontrolled Copy in Print) Page 5 of 81

p. OSHA 29 CFR 1926.957 Subpart V, Electric Power Transmission and Distribution 148

q. OSHA 29 CFR 1910.301 Subpart S, Electrical 150

r. OSHA 29 CFR 1926.400 Subpart K, Electrical 152

s. National Fire Protection Association (NFPA) 70, National Electric Code, latest edition. 154

t. NFPA 70B, Standard for Electrical Equipment Maintenance, latest edition 156

u. NFPA 70E, Electrical Safety in the Workplace, latest edition 158

v. NFPA 79, Electrical Standard for Industrial Machinery, latest edition. 160

w. NFPA 790 Standard for Competency of Third-Party Field Evaluation Bodies, latest edition 162

x. NFPA 791, Recommended Practice and Procedures for Unlabeled Electrical Equipment 164 Evaluation, latest edition 165

y. Underwriters Laboratory (UL) 508, Industrial Control Equipment, latest edition. 167

z. UL 508A, Industrial Control Panels; latest edition. 169

aa. UL 60950-1, Standard for Safety, Information Technology Equipment – Safety; Part 1: 171

General requirements; latest edition. 172

bb. UL 61010-1, Standard for Safety, Electrical Equipment for Measurement, latest edition. 174 Control, and Laboratory Use; Part 1: General Requirements, latest edition. 175

5. APPLICABLE NIST DIRECTIVES 178

a. NIST S 7101.20: Work and Worker Authorization Based on Hazard Reviews 179

b. NIST S 7101.21: Personal Protective Equipment (PPE) 181

c. NIST S 7101.23: Safety Education and Training 183

d. NIST S 7101.24: Incident Reporting and Investigation 185

e. NIST S 7101.28: Non-R&D Contractor Safety Program (under development) 187 https://www.osha.gov/laws-regs/regulations/standardnumber/1926/1926.957 https://www.osha.gov/pls/oshaweb/owadisp.show_document?p_table=STANDARDS&p_id=10135 https://www.osha.gov/pls/oshaweb/owadisp.show_document?p_table=STANDARDS&p_id=10915 https://www.nist.gov/oshe/safety-programs/work-and-worker-authorization-based-hazard-reviews-hazard-review https://www.nist.gov/oshe/safety-programs/personal-protective-equipment-ppe https://www.nist.gov/oshe/safety-programs/safety-education-and-training-set-program https://www.nist.gov/oshe/safety-programs/incident-reporting-and-investigation

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f. NIST S 7101.55: Hearing Protection 188

g. NIST S 7101.56: Control of Hazardous Energy (Lockout/Tagout) 190

h. NIST S 7101.57: Permit-Required Confined Spaces 192

i. NIST S 7101.73: Out of Service 194

j. NIST PR 7101.00: Procedure for Requesting Safety-Related Variances and Waivers 196 (Internal link only) 197

6. REQUIREMENTS 200

a. General Electrical Safety Requirements for Any Workspace or Work Activity 201

(1) Electrical Cord Plugs of Any Kind 203

(a) When in use, an electrical cord plug of any kind (e.g., on an extension cord or 205 associated with a power cord to a computer or piece of lab equipment) shall be fully 206 inserted into an electrical outlet such that the plug’s metal prongs are not exposed. 207

(b) A damaged plug (e.g., broken, cracked, or missing prongs or ground pins) of any kind 209 shall be removed from service immediately. 210

i. If the cord or equipment the plug is connected to can be discarded, it shall be 212 discarded immediately. 213

ii. If the cord or equipment the plug is connected to is to be repaired, it shall be 215 immediately tagged out of service in accordance with the requirements of 216 NIST S 7101.73 until the repair is complete. 217

(c) Three-prong to two-prong plug adapters shall not be used in lieu of proper circuit 219 grounding. 220

i. During the course of a work activity, when it is required for the purpose of 222 ground loop isolation, a “break-out” box or other type of isolation device shall 223 be developed that will provide ground loop isolation with a visible indication 224 that the ground has been inhibited. 225 https://www.nist.gov/oshe/safety-programs/hearing-protection-program https://www.nist.gov/oshe/safety-programs/control-hazardous-energy-lockouttagout-or-loto https://www.nist.gov/oshe/safety-programs/permit-required-confined-spaces https://www.nist.gov/oshe/safety-programs/out-service-oos https://nistsafety.nist.gov/SafetyWeb/DocumentCenter/ViewDoc/2412

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(2) Electrical Cords of Any Kind 229

(a) When plugged into outlets, the tension on an electrical cord of any kind (e.g., an 231 extension cord or power cord to a computer or piece of lab equipment) shall be 232 minimized to the extent possible and not exceed manufacturers recommendations for 233 tension. 234

(b) An electrical cord of any kind shall be protected from damage. 236

i. An electrical cord of any kind shall not be pinched, bent, or similarly 238 deformed such that the insulation or conductors are compromised. This does 239 not apply to compression connections. 240

ii. A cord guard shall be used to protect an electrical cord of any kind positioned 242 across a walkway from wear and tear caused by foot and other traffic. 243

(i) The cord guard shall be secured to prevent tripping. 245

(ii) An electrical cord of any kind shall not be taped (e.g., gaffer tape) to 247 the floor in any location where there is foot or other traffic. The 248 electrical cord may be taped down in locations where there will not be 249 foot or other traffic (e.g., under tables or on the floor directly adjacent 250 to a wall). 251

(c) An electrical cord of any kind shall not be securely fastened to building surfaces as 253 permanent installations. 254

(d) A damaged cord of any kind (e.g., a cord that is pinched, is missing insulation, has 256 exposed conductors) shall be removed from service immediately. 257

i. If the cord or equipment the cord is connected to can be discarded, it shall be 259 immediately discarded. 260

ii. If the cord or equipment the cord is connected to is to be repaired, it shall be 262 immediately tagged out of service in accordance with the requirements of 263 NIST S 7101.73 until the repair is complete. 264

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(3) Supplemental Power Devices 269

(a) Supplemental power devices shall be labeled and listed by a Nationally Recognized 271

Testing Laboratory (NRTL)4, e.g., Underwriters Laboratories. Examples of 272 supplemental power devices are relocatable power taps (RPTs), surge suppressors, 273 power strips, uninterruptible power supplies (UPS), power distribution units (PDUs) 274 and extension cords. 275

i. An unlisted supplemental power device may be used in a laboratory or R&D 277 workspace provided it is first evaluated per NFPA 791, as discussed in 278 Section 6.j. 279

ii. An acceptable RPT shall meet the following requirements5: 281

(i) Is listed for commercial or industrial applications; 283

(ii) Has a master circuit breaker; and 285

(iii) Has a master power switch. 287

(b) Only a supplemental power device that is grounded shall be used. Please see Section 289

6.a(1)(c). 290

(c) When not in use, a supplemental power device shall be stored according to the 292 manufacturer’s safety instructions. 293

(d) A supplemental power device shall be used according to the manufacturer’s safety 295 instructions. 296

(e) A supplemental power device shall be connected directly to a permanently installed 298 electrical outlet, i.e., “daisy chaining” or “piggybacking” to other supplemental power 299 devices is not permitted. 300

(f) The cord of a supplemental power device shall not be routed through walls, floors, 302 windows, doorways, or ceilings. 303

4 https://www.osha.gov/nationally-recognized-testing-laboratory-program/current-list-of-nrtls 5 In general, acceptable RPTs shall be NRTL listed for the application and used in accordance with the NRTL listing.

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(g) A supplemental power device may be secured in place in accordance with the 305 requirements of their NRTL listing. 306

(h) A supplemental power device shall not be modified in any manner including for the 308 purpose of mounting except as specified by the manufacturer using manufacturer 309 supplied or recommended parts. 310

(i) A supplemental power device shall not be opened unless the operator’s manual 312 provided by the manufacturer allows and includes instructions for doing so. 313

(j) Extension cords shall not be used as a substitute for permanent wiring and shall be 315 unplugged and properly stored after temporary use. 316

i. Temporary use is defined by NFPA 70 as no longer than 90 days. 318

ii. An extension cord may be used in a laboratory or R&D workspace for the 320 duration of the experiment or research effort. 321

iii. An extension cord may be used for the duration of construction, remodeling, 323 maintenance, repair, or demolition of building structures, components, or 324 similar activities, please see Section 6.b(1). 325

(k) A damaged supplemental power device shall be removed from service immediately. 327

i. If the supplemental power device can be discarded, it shall be immediately 329 discarded. 330

ii. If the supplemental power device is to be repaired, it shall be immediately 332 tagged out of service in accordance with the requirements of NIST S 7101.73 333 until the repair is complete. 334

(4) Appliances 336

(a) An appliance shall be labeled and listed by an NRTL and used in accordance with 338 listing instructions. 339

i. Unlisted appliances may be approved for used in a laboratory or R&D 341 workspace provided it is first evaluated per NFPA 791, as discussed in 342 Section 6.j. 343

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(b) Manufacturer’s safety instructions shall be followed for appliance use. 345

(c) An electrical appliance that has a current load greater than 12 amperes (power loads 347 greater than 1440 Watts), e.g., space heater, refrigerator, microwave oven, shall be 348 plugged directly into: 349

i. A permanently installed electrical outlet (i.e., wall receptacle); or 351

ii. A relocatable power tap (RPT) meeting the requirements in Section 353

6.a(3)(a)ii. 354

(d) An electrical appliance with a heating element, e.g., portable electric space heater, 356 coffee pot, toaster, toaster oven, shall be plugged directly into: 357

i. A permanently installed electrical outlet (i.e., wall receptacle); or 359

ii. A RPT meeting the requirements in Section 6.a(3)(a)ii. 361

(e) Manufacturer’s clearance requirements shall be maintained around an electrical 363 appliance with a heating element, e.g., coffee pot, toaster, toaster oven. 364

(f) When in use, a toaster, toaster oven, or other cooking appliances (e.g., microwave) 366 shall be attended, i.e., the individual using the appliance shall remain in the space 367 where the appliance is located while it is in use. 368

(g) Ground fault circuit interruption (GFCI) protection shall be used (as per NFPA 70) 370 when cord-and-plug connected equipment and tools are used in wet or damp locations 371 and supplied by a 125V 15A or 20A circuit. 372

NOTE: NFPA 70 requires GFCI protection when an outlet is within 6 feet of a 374 water source. If the outlet is not GFCI protected, a GFCI plug is required to be 375 used with the appliance. Wet or Damp locations are defined in NFPA 70. 376

(5) Electrical Equipment and Tools 378

(a) Electrical equipment and tools shall be labeled and listed by an NRTL and used in 380 accordance with listing instructions. 381

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i. Unlisted electric equipment and tools may be approved for use in a laboratory 383 or R&D workspace provided they are first evaluated per NFPA 791, as 384 discussed in Section 6.j. 385

(b) Electrical equipment and tools that have current loads greater than 12 amperes (power 387 loads greater than 1440 Watts) shall be plugged directly into: 388

i. A permanently installed electrical outlet (i.e., wall receptacle); or 390

ii. A RPT meeting the requirements in Section 6.a(3)(a)ii. 392

(c) Ground fault circuit interruption (GFCI) protection shall be used when cord-and-plug 394 connected equipment and tools are used in wet or damp locations and supplied by a 395 125V 15A or a 20A circuit. 396

NOTE: NFPA 70 requires GFCI protection when an outlet is within 6 feet of a 398 water source. If the outlet is not GFCI protected, a GFCI plug is required to be 399 used with the electrical equipment or tool. 400

(6) Permanently Installed Electrical Outlets (i.e., Wall Receptacles and Pendant Power 402

Outlets) 403

(a) The load on permanently installed electrical 120V outlets shall not exceed: 405

i. 12 amperes (1440Watts) for a 15-amp circuit; or 407

ii. 16 amperes (1920 Watts) for a 20-amp circuit. 409

NOTE: Most circuits in offices and office-like spaces at NIST are 20-ampere 411 circuits, but some are 15-ampere circuits. If you wish to attach more than a 412 12-ampere (1440 W) load and you are not sure if the circuit is 20-ampere 413 circuit, contact the OFPM Service Desk: 414

• Boulder: 303-497-3191 416

• Gaithersburg: 301-975-6928 417

(b) Electrical outlets with broken, missing, and/or cracked cover plates shall be: 419

i. Marked out of service in accordance with the requirements of NIST S 7101.73 421 until the repair is complete; and 422

NIST S 7101.64, Ver. 1a (Uncontrolled Copy in Print) Page 12 of 81

ii. Submitted in an M-slip, or reported as soon as possible to the OFPM Service 423 Desk for repair or replacement at the following numbers: 424

• Boulder: 303-497-3191 426

• Gaithersburg: 301-975-6928 427

(c) Per the requirements of Section 6.k(1), permanently installed electrical outlets located 429 in wet or damp locations, and specifically within 6 feet of a water source6, shall have 430 GFCI protection. 431

(7) Electrical Panels 433

(a) The working space around electrical panels7 shall be kept clear as outlined in NFPA 435

70, Article 110. 436

i. Electrical panels supplied by 150 volts or less shall have a minimum of 36 438 inches (0.91 m) of clearance in the direction of the panel. 439

ii. Electrical panels supplied by greater than 150 volts shall have a minimum of 441 42 inches (1.07 m) of clearance in the direction of the panel. 442

(b) Moveable objects (e.g., furniture, equipment, materials) shall not be placed in front of 444 electrical panels. 445

(c) The working space shall permit at least a 90-degree opening of hinged panels. 447

i. Only OFPM or OFPM Director-authorized individuals shall operate breakers 449 inside of electrical panels. 450

b. Provision of Temporary Electrical Power 452

(1) Means of providing temporary electrical power (e.g., use of extension cords) shall only 454 be permitted for the following types of work: 455

(a) Renovation; 457

(b) Construction; 459

6 Emergency eyewashes and safety showers are not considered water sources.

7 It is presumed that electrical panels in NIST offices and office-like spaces are supplied by 150 volts or less.

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(c) Maintenance; 461

(d) Repair; 463

(e) Testing; and 465

(f) In laboratory and R&D workspaces, please see Section 6.a.(3)(j)ii. 467

(2) When used in wet or damp locations and on construction sites, the method to provide 469 temporary electrical power shall have ground fault circuit interrupter protection (GFCI). 470

c. Work on Electrical, Electronic, and Electro-Mechanical Equipment and Circuits 472

NOTES: 474

• Prior to reviewing Section 6.c, the reader must have an understanding of the 475 content contained in Appendix B. 476

• The requirements found in Section 6.c must be incorporated into the appropriate 477 risk assessment (e.g., hazard review or job hazard analysis) in accordance with the 478 requirements of NIST S 7101.20. 479

• Those conducting the risk assessment must be qualified, per the appropriate table 480 in Section 6.c, and have a thorough understanding of the work planned to 481 appropriately analyze for hazards and identify subsequent control measures. If 482 they do not, a subject matter expert with the appropriate knowledge, skills, and 483 abilities must be consulted, in accordance with NIST S 7101.20. 484

• As part of the risk assessment process, electrical hazards should be categorized 485 based upon the energy source, type, and other characteristics. Section 6.c is laid 486 out as follows: 487

− Section 6.c(1): General work requirements regardless of hazard category 488 or hazard class. 489

The remaining sub-sections of Section 6.c provide general control measures, 490 worker qualifications, and PPE type corresponding to specific hazard 491 category, hazard class, and mode of electrical work. 492 − Section 6.c(2): Alternating current (AC) sources, equipment, or systems 493 that use 50-60 Hz; 494 − Section 6.c(3): Direct current (DC) power sources; 495 − Section 6.c(4): Capacitors; 496 − Section 6.c(5): Batteries; and 497 − Section 6.c(6): Radiofrequency. 498

• Special care must be taken during the risk assessment process to ensure all 499 electrical hazards are identified as more than one may be present in performance 500

NIST S 7101.64, Ver. 1a (Uncontrolled Copy in Print) Page 14 of 81 of the work. Example – a single piece of equipment may have multiple energy 501 sources and the combination of hazards associated with those sources must be 502 addressed by the appropriate controls in total. 503

• The requirements for the control measures identified in Sections 6.c(2) through 504 6.c(6) are found in subsequent sections: 505

− Section 6.d: Establishment of an electrically safe working condition; 506 − Section 6.e: Provision of an energized electrical work permit; 507 − Section 6.f: Additional requirements for energized electrical work greater 508 than 600 V (High-Voltage) 509 − Section 6.g: Establishment of boundaries using barricades; 510 − Section 6.h: Employment of a two-person work rule; and 511 − Section 6.i: PPE and other protective equipment. 512

(1) General Requirements for Any Hazard Category or Hazard Class 514

(a) Work on electrical, electronic, and electro-mechanical equipment and circuits shall be 516 planned and authorized in accordance with the requirements of NIST S 7101.20. 517

(b) Work on electrical, electronic, and electro-mechanical equipment and circuits should 519 be performed under electrically safe working conditions, i.e., de-energized state or 520 Mode 0. Section 6.d provides requirements for establishing this condition. 521

(c) Work may be performed on electrical, electronic, and electro-mechanical equipment 523 and circuits in an energized state, i.e., energized electrical work. 524

i. Energized electrical work may be performed provided one of the following 526 conditions are met: 527

(i) Energized electrical conductors and circuit parts to which workers 529 could be exposed operate at less than 50 V AC or 100V DC and no 530 other electrical hazards8, e.g., potential for electrical burns or 531 explosion, exist; 532

(ii) It can be demonstrated to the responsible organizational unit (OU) line 534 management that de-energizing would introduce additional hazards, 535 would introduce increased risk, or could cause significant property 536 damage or loss of critical data; 537

8 Per DOE Handbook, Table E-1

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(iii) It can be demonstrated to the responsible OU line management that 539 performing the work in a de-energized state is infeasible (not just 540 inconvenient) due to equipment design or operational limitations; or 541

(iv) The equipment is being operated as intended, e.g., breakers, service 543 disconnects, and the equipment, circuits, and upstream protective 544 devices are known to be properly installed and maintained9. 545

NOTE: Where it cannot be determined that the upstream protective 547 devices are properly installed and maintained, they should only be 548 operated with caution using appropriate PPE as determined by the 549 hazard review process. 550

ii. Energized electrical work may be performed with and without an energized 552 electrical work permit (EEWP) depending on the criteria noted in 6.c(1)(c) iii 553 and iv below. 554

iii. Energized Electrical Work Not Requiring an EEWP 556

(i) The following energized electrical work may be performed without an 558

EEWP: 559

• Performing diagnostics, testing, troubleshooting, or voltage 561 measuring (e.g., taking readings or measurements of electrical 562 equipment with approved test equipment that do not require 563 making any physical changes to the equipment); 564

• Performing thermography and visual inspections if the 566 restricted approach boundary is not crossed; 567

• Performing tasks involving access to and egress from an area 569 with energized electrical equipment or circuits if no energized 570 electrical work is performed and the restricted approach 571 boundary is not crossed; or 572

• Performing general housekeeping and miscellaneous non-574 electrical tasks if the restricted approach boundary is not 575 crossed and all automatic/remotely activated controls are 576 inhibited. 577

9 “Properly installed and maintained” is defined by requirements found in NFPA 70E, NFPA 70B.

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(ii) Staff performing energized electrical work without an EEWP shall: 578

• Be a qualified individual; 580

• Be trained on the appropriate safe work practices associated 582 with the task(s); and 583

• Use the appropriate PPE as determined by the method used to 585 authorize the work, please see Section 6.c(1)(a). 586

iv. Energized Electrical Work Requiring an EEWP 588

(i) In addition to the types of work identified in Tables 6.1 through 6.5 590 below, activities requiring a qualified person to work within the 591 restricted approach boundary shall be conducted in accordance with 592 the requirements of an authorized EEWP, please see Section 6.e. 593

(d) NIST staff members performing work on electrical, electronic, and electro-595 mechanical equipment or circuits shall: 596

i. Make a concerted effort to eliminate all unsafe conditions, behaviors, or 598 attitudes in their own work and that of others they are working with; 599

ii. Consider participating in a pre-job briefing to understand thoroughly the work 601 to be performed, including each worker’s part in the work, hazards associated 602 with the job, required control measures, and any other special precautions; 603

NOTE: Performing EEW using an EEWP requires a pre-job briefing. 605

iii. Be trained in and use all applicable control measures including required 607 protective devices; 608

iv. Never distract the attention of another individual while they are performing 610 electrical work; 611

v. Report all incidents and injuries to their supervisor; and 613

vi. Have their condition evaluated immediately by a medical professional if they 615 receive an electrical shock or are exposed to an arc flash. 616

NIST S 7101.64, Ver. 1a (Uncontrolled Copy in Print) Page 17 of 81

(e) When a new NIST staff member performs electrical work, or an existing NIST staff 618 member performs work not previously performed, they shall work under the 619 supervision of an experienced NIST staff member who will explain in detail the 620 specific hazards of the work to be performed and the safety rules and procedures 621 necessary to ensure their safety; 622

i. The new NIST staff member performing electrical work or the existing NIST 624 staff member performing work not previously performed shall remain 625 supervised until the experienced NIST staff member believes they have the 626 knowledge, skills, and abilities to perform the work without supervision. 627

NOTE: Per NIST S 7101.20, authorization of a staff member to perform 629 work is the responsibility of the supervisor. The supervisor may rely on 630 others to assist in determining if the staff member is authorized to perform 631 work, e.g., the "experienced NIST staff member". 632

(2) Work Involving Hazard Category A: AC Sources, Equipment, or Systems that Use 50-60 634

Hz 635 Table 6.1 provides the minimum control measures, PPE, and training qualifications 636 required when staff will be performing tasks involving Hazard Category A sources given 637 different hazard classes and modes of electrical work. This information shall be 638 incorporated into the appropriate hazard review or job hazard analysis. 639

NOTES: 641

• Most small appliances, hand tools, and portable laboratory equipment 642 running from 120V wall supply falls under Hazard Category A, Hazard 643 Class 2.a. 644

• UPSs fall under Hazard Category A, Hazard Class 2.a, but must be 645 evaluated for Hazard Category B and D as well. 646

• Larger facility and laboratory equipment may use up to 480 V (Hazard 647 Category A, Hazard Class 3.a and 3.b). Often, if it is a large switchgear, or 648 has significant available fault current, it may be Hazard Class 4. 649

NIST S 7101.64, Ver. 1a (Uncontrolled Copy in Print) Page 18 of 81

Table 6.1: Minimum requirements for work involving Hazard Category A 651 Hazard Class Hazard Sub-Class Electrical Work

Mode Two-person work rule Qualifications Control Measures 1 PPE2

Hazard Class 1.a <15 V All Alone Limited-Scope Qualified None No specific ES PPE

Hazard Class 1.b 15–50 V All Alone Limited-Scope Qualified None No specific ES PPE

Hazard Class 2.a 50-250V Single Phase

0 Alone

Limited-Scope Qualified

LOTO and ZVV Minimum ES PPE 1 Alone LOTO and ZVV

Shock PPE 2 Alone Barricade 3 Alone EEWP

Hazard Class 2.b 208-300V Single Phase without arc flash hazard

0 Alone

Limited-Scope Qualified

LOTO and ZVV Minimum ES PPE 1 Alone LOTO and ZVV

Shock PPE 2 Alone Barricade 3 Alone EEWP

Hazard Class 3.a 3-phase 208-300V with arc flash hazard

0 Alone

Comprehensive Qualified

LOTO and ZVV Minimum ES PPE 1 Alone LOTO and ZVV Shock PPE;

Arc Flash PPE 2 Alone Barricade 3 Alone EEWP

Hazard class 3.b 3-phase 301-750V

0 Alone

Comprehensive Qualified

LOTO and ZVV Minimum ES PPE 1 Standby Person LOTO and ZVV Shock PPE;

Arc Flash PPE 2 Safety Watch Barricade 3 Safety Watch EEWP

Hazard class 4 3-phase >750V

0 Alone

High-Voltage Qualified

LOTO and ZVV Minimum ES PPE 1 Safety Watch LOTO and ZVV Shock PPE;

Arc Flash PPE 2 Safety Watch Barricade 3 Safety Watch EEWP

Table notes:

1. Control Measures:

a. These control measures are in addition to those determined during the risk assessment conducted in accordance with the requirement of NIST S 7101.20.

b. LOTO and ZVV: Lockout/Tagout and Zero Voltage Verification. Please see Section 6.d for requirements to establish this electrically safe working condition.

c. EEWP: Please see Section 6.c.

d. Barricade: Please see Section 6.g.

e. Hazard Class 3 and 4 assume potential arc flash hazard exists.

f. The two-person work rule requirements for Standby Person or Safety Watch noted in the table above only apply per OSHA 1910.269 or when direct incident energy exposure is > 40 cal/cm^2. Otherwise, Standby Person or Safety Watch is not required, although it is recommended as a good practice. Exceptions to OSHA 1910.269 are provided in 1910.269(l)(2)(ii).

2. PPE

a. “No specific ES PPE” means no specific electrical safety PPE is required, but the worker is required to wear other PPE as determined by the risk assessment.

b. “Minimum ES PPE” means the worker is required to wear (1) a long sleeve shirt and pants that are NOT made from a flammable synthetic material, e.g., acetate, nylon, polyester, polypropylene, or spandex either alone or in blends; (2) safety glasses; and (3) hearing protection per the requirements of NIST S 7101.55.

c. “Shock PPE” means PPE is determined by performing a shock risk assessment using methods covered in Article 130 of NFPA 70E.

d. “Arc Flash PPE” means PPE is determined by performing an arc flash risk assessment as discussed in NFPA 70E.

NIST S 7101.64, Ver. 1a (Uncontrolled Copy in Print) Page 19 of 81

(3) Work Involving Hazard Category B: DC Power 653 Table 6.2 provides the minimum control measures, PPE, and training qualifications 654 required when staff will be performing tasks involving Hazard Category B sources given 655 different hazard classes and modes of electrical work. This information shall be 656 incorporated into the appropriate hazard review or job hazard analysis. 657

NOTES: 659

• DC power supplies need to be evaluated for both DC (Hazard Category B) 660 and Capacitance (Hazard Category C). 661

NIST S 7101.64, Ver. 1a (Uncontrolled Copy in Print) Page 20 of 81

Table 6.2: Minimum requirements for work involving Hazard Category B 663

Class Hazard Sub-Class Electrical Work

Mode Two-person work rule Qualifications Control Measures1 PPE2

Hazard Class 1.a <15 V, < 100 W All Alone Limited-Scope Qualified None No specific ES PPE

Hazard Class 1.b < 100V, ≤1KW; or >100V, ≤40mA All Alone Limited-Scope Qualified None No specific ES PPE

Hazard Class 2.a

≤ 15V, >1KW

0 Alone

Limited-Scope Qualified None No specific ES PPE 1 Alone 2 Alone 3 Alone

Hazard Class 2.b

15-100V, >1KW

0 Alone

Limited-Scope Qualified None No specific ES PPE 1 Alone 2 Alone 3 Alone

Hazard Class 2.c ≥100-400V, 40 mA-500 A

0 Alone

Comprehensive Qualified

LOTO and ZVV Minimum ES PPE 1 Alone LOTO and ZVV

Shock PPE 2 Alone Barricade 3 Alone EEWP

Hazard Class 2.d >400V, 40-200 mA

0 Alone

Comprehensive Qualified

LOTO and ZVV Minimum ES PPE 1 Alone LOTO and ZVV

Shock PPE 2 Alone Barricade 3 Alone EEWP

Hazard Class 3.a 100-400V, >500 A

0 Alone

Comprehensive Qualified

LOTO and ZVV Minimum ES PPE 1 Alone LOTO and ZVV Shock PPE;

Arc Flash PPE 2 Alone Barricade 3 Alone EEWP

Hazard Class 3.b ≥400v, 200 mA- 500 A

0 Alone

Comprehensive Qualified

LOTO and ZVV Minimum ES PPE 1 Standby Person LOTO and ZVV Shock PPE;

Arc Flash PPE 2 Safety Watch Barricade 3 Safety Watch EEWP

4 Hazard Class 4 >400 V, >500 A

0 Alone

Comprehensive Qualified

LOTO and ZVV Minimum ES PPE 1 Standby Person LOTO and ZVV Shock PPE;

Arc Flash PPE 2 Safety Watch Barricade 3 Safety Watch EEWP

Table notes:

1. Control Measures:

a. These control measures are in addition to those determined during the risk assessment conducted in accordance with the requirement of NIST S 7101.20.

b. LOTO and ZVV: Lockout/Tagout and Zero Voltage Verification. Please see Section 6.d for requirements to establish this electrically safe working condition.

c. EEWP: Please see Section 6.c.

d. Barricade: Please see Section 6.g.

e. The two-person work rule requirements for Standby Person or Safety Watch noted in the table above only apply per OSHA 1910.269 or when direct incident energy exposure is > 40 cal/cm^2. Otherwise, Standby Person or Safety Watch is not required, although it is recommended as a good practice. Exceptions to OSHA 1910.269 are provided in 1910.269(l)(2)(ii).

a. “No specific ES PPE” means no specific electrical safety PPE is required, but the worker is required to wear other PPE as determined by the risk assessment.

NIST S 7101.64, Ver. 1a (Uncontrolled Copy in Print) Page 21 of 81

b. “Minimum ES PPE” means the worker is required to wear (1) a long sleeve shirt and pants that are NOT made from a flammable synthetic material, e.g., acetate, nylon, polyester, polypropylene, or spandex either alone or in blends; (2) safety glasses; and (3) hearing protection per the requirements of NIST S 7101.55.

c. “Shock PPE” means PPE is determined by performing a shock risk assessment using methods covered in Article 130 of NFPA 70E.

d. “Arc Flash PPE” means PPE is determined by performing an arc flash risk assessment as discussed in NFPA 70E.

NIST S 7101.64, Ver. 1a (Uncontrolled Copy in Print) Page 22 of 81

(4) Work Involving Hazard Category C: Capacitors 665 Tables 6.3a and 6.3b provides the minimum control measures, PPE, and training 666 qualifications required when staff will be performing tasks involving Hazard Category C 667 sources given different hazard classes and modes of electrical work. This information 668 shall be incorporated into the appropriate hazard review or job hazard analysis. 669

NIST S 7101.64, Ver. 1a (Uncontrolled Copy in Print) Page 23 of 81

Table 6.3a: Minimum requirements for work involving Hazard Category C - Capacitors < 400 V 672

Class Hazard Sub-Class Electrical

Work Mode Two-person work rule Qualifications Control Measures1 PPE2 Stored Energy Removal3

1 Hazard Class 1.b 100-399 V, < 10 J All Alone Limited-Scope Qualified None No specific ES

PPE None

Hazard Class 2.a <100 V, 100 J – 999 J

Alone

Limited-Scope Qualified;

Capacitor Safety Qualified LOTO and ZVV Safety Glasses

None 1 Hard Ground Hook 2 Hard Ground Hook 3 Hard Ground Hook

Hazard Class 2.b 100-399 V, 10 J – 99 J

0 Alone Comprehensive Qualified;

Capacitor Safety Qualified

LOTO and ZVV Minimum ES PPE None 1 Alone LOTO and ZVV Shock PPE Hard Ground Hook 2 Alone Barricade Shock PPE Hard Ground Hook 3 Alone EEWP Shock PPE Hard Ground Hook

Hazard Class 3.a < 100V, 1 kJ – 9.9 kJ

0 Alone Comprehensive Qualified;

Capacitor Safety Qualified

LOTO and ZVV Minimum ES PPE None 1 Alone LOTO and ZVV Shock PPE Soft ground hook > 1 kJ 2 Alone Barricade Shock PPE Soft ground hook > 1 kJ 3 Alone EEWP Shock PPE Soft ground hook > 1 kJ

Hazard class 3.b 100-399 V, 100 J – 9.9 kJ

0 Alone Comprehensive Qualified;

Capacitor Safety Qualified

LOTO and ZVV Minimum ES PPE None 1 Alone LOTO and ZVV Shock PPE Soft ground hook > 1 kJ 2 Alone Barricade Shock PPE Soft ground hook > 1 kJ 3 Alone EEWP Shock PPE Soft ground hook > 1 kJ

Hazard class 4.a < 100 V, ≥ 10 kJ

0 Alone Comprehensive Qualified;

Capacitor Safety Qualified

LOTO and ZVV Minimum ES PPE None 1 Standby Person LOTO and ZVV Shock PPE Remote soft ground 2 Safety Watch Barricade Shock PPE Remote testing 3 Safety Watch EEWP Shock PPE Remote testing

Hazard class 4.b 100-399V, ≥ 10kJ

0 Alone

Comprehensive Qualified;

Capacitor Safety Qualified

LOTO and ZVV Minimum ES PPE None

1 Standby Person LOTO and ZVV Shock PPE;

Arc Flash PPE Remote soft ground

2 Safety Watch Barricade Shock PPE;

Arc Flash PPE Remote testing

3 Safety Watch EEWP Shock PPE;

Arc Flash PPE Remote testing

Table notes:

1. Control Measures:

a. These control measures are in addition to those determined during the risk assessment conducted in accordance with the requirement of NIST S 7101.20.

b. LOTO and ZVV: Lockout/Tagout and Zero Voltage Verification. Please see Section 6.d for requirements to establish this electrically safe working condition.

c. EEWP: Please see Section 6.c.

d. Barricade: Please see Section 6.g.

e. The two-person work rule requirements for Standby Person or Safety Watch noted in the table above only apply per OSHA 1910.269 or when direct incident energy exposure is > 40 cal/cm^2. Otherwise, Standby Person or Safety Watch is not required, although it is recommended as a good practice. Exceptions to OSHA 1910.269 are provided in 1910.269(l)(2)(ii).

NOTE: For Hazard Class 4, Modes 2 and 3, work should be avoided or performed remotely.

NIST S 7101.64, Ver. 1a (Uncontrolled Copy in Print) Page 24 of 81

a. “No specific ES PPE” means no specific electrical safety PPE is required, but the worker is required to wear other PPE as determined by the risk assessment.

b. “Minimum ES PPE” means the worker is required to wear (1) a long sleeve shirt and pants that are NOT made from a flammable synthetic material, e.g., acetate, nylon, polyester, polypropylene, or spandex either alone or in blends; (2) safety glasses; and (3) hearing protection per the requirements of NIST S 7101.55.

c. “Shock PPE” means PPE is determined by performing a shock risk assessment using methods covered in Article 130 of NFPA 70E.

d. “Arc Flash PPE” means PPE is determined by performing an arc flash risk assessment as discussed in NFPA 70E.

3. Stored Energy Removal - a method used to discharge lower-energy capacitors or apply a safety ground on higher-energy capacitors.

a. “Remote soft ground” means using engineering methods to discharge and verify the capacitors without worker exposure (e.g., a capacitor remote dump or discharge system). Refer NFPA 70E (latest version) Annex R for additional information.

b. “Remote testing” means using sensors and instruments that are placed during a Mode 0 condition, then observed from a safe location during Mode 2 work.

c. Ratings for ground hooks should exceed maximum stored energy values.

NIST S 7101.64, Ver. 1a (Uncontrolled Copy in Print) Page 25 of 81

Table 6.3b: Minimum requirements for work involving Hazard Category C – Capacitors ≥ 400 V 674

Class Hazard Sub-Class Electrical Work

Mode Two-person work rule Qualifications Control

Measures1 PPE2 Stored Energy Removal3

Electro-static Discharge (ESD) All Alone Limited-Scope Qualified None No specific ES PPE None Hazard Class 1 ≥ 400 V, < 10 J

All Alone Limited-Scope Qualified None No specific ES PPE Hard ground

2 Hazard Class 2 ≥ 400 V, 10 J – 49 J

0 Alone Comprehensive Qualified;

Capacitor Safety Qualified

LOTO and ZVV Minimum ES PPE

1 Alone LOTO and ZVV Shock PPE Hard ground 2 Standby Barricade Shock PPE 3 Safety Watch EEWP Shock PPE

Hazard Class 3.a ≥ 400 V, 50 J – 999 J

0 Alone Comprehensive Qualified;

Capacitor Safety Qualified

LOTO and ZVV Minimum ES PPE 1 Standby Person LOTO and ZVV Shock PPE Hard ground 2 Safety Watch Barricade Shock PPE 3 Do not proceed with this mode of work

Hazard Class 3.b ≥ 400 V, 1 kJ – 9.9 kJ

0 Alone High-Voltage Qualified;

Capacitor Safety Qualified

LOTO and ZVV Minimum ES PPE

1 Standby Person LOTO and ZVV Shock PPE Soft ground hook rated appropriately

2 Safety Watch Barricade Shock PPE 3 Do not proceed with this mode of work

4 Hazard Class 4 ≥ 400 V, > 10 kJ

0 Alone

High-Voltage Qualified;

Capacitor Safety Qualified

LOTO and ZVV Minimum ES PPE

1 Alone LOTO and ZVV Shock PPE;

Arc Flash PPE;

Hearing protection

Soft ground hook rated appropriately

2 Standby Person Barricade Shock PPE;

Arc Flash PPE;

Hearing protection

Remote testing

3 Do not proceed with this mode of work Table notes:

1. Control Measures:

a. These control measures are in addition to those determined during the risk assessment conducted in accordance with the requirement of NIST S 7101.20.

b. LOTO and ZVV: Lockout/Tagout and Zero Voltage Verification. Please see Section 6.d for requirements to establish this electrically safe working condition.

c. EEWP: Please see Section 6.c.

d. Barricade: Please see Section 6.g.

e. The two-person work rule requirements for Standby Person or Safety Watch noted in the table above only apply per OSHA 1910.269 or when direct incident energy exposure is > 40 cal/cm^2; otherwise, Standby Person or Safety Watch is not required, although it is recommended as a good practice. Exceptions to OSHA 1910.269 are provided in 1910.269(l)(2)(ii).

2. PPE

a. “No specific ES PPE” means no specific electrical safety PPE is required, but the worker is required to wear other PPE as determined by the risk assessment.

b. “Minimum ES PPE” means the worker is required to wear (1) a long sleeve shirt and pants that are NOT made from a flammable synthetic material, e.g., acetate, nylon, polyester, polypropylene, or spandex either alone or in blends; (2) safety glasses; and (3) hearing protection per the requirements of NIST S 7101.55.

c. “Shock PPE” means PPE is determined by performing a shock risk assessment using methods covered in Article 130 of NFPA 70E.

d. “Arc Flash PPE” means PPE is determined by performing an arc flash risk assessment as discussed in NFPA 70E.

3. Stored Energy Removal - a method used to discharge…