Electrical Safe Work Practice

7/27/2019 Electrical Safe Work Practice

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ELECTRICAL SAFE WORK PRACTICE

PROCEDURE NUMBER: HES-206


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CPL HES 206 Electrical Safe Work Practice

Revised/Printed September 2010, Uncontrolled when printed HES 206 Electrical Safe Work Practice

CONTENTS

ELECTRICAL SAFE WORK PRACTICES HES-206

Section Title Page

1.0 Purpose 206 - 1

2.0 Scope 206 - 1

3.0 Roles and Responsibilities 206 - 2

4.0 Safe Work Processes 206 - 3

5.0 New Design, Modification, and Construction 206 - 40

5.1 Equipment Design Considerations 206 - 40

5.2 Substations 206 - 41

5.3 Guarding Live Parts 206 - 42

5.4 New Static Capacitor Banks 206 - 43

5.5 Lines 206 43

5.6 Perimeter Fence Grounding 206 475.7 Pipelines, Conveyors, and Metal Structures 206 47

5.8 Signage 206 47

5.9 Equipment Labeling, Marking, and Identification 206 48

6.0 Operation and Maintenance 206 - 49

7.0 Inspection and Testing of Insulating Rubber Products, Tools, and Mechanized Equipment

206 - 52

8.0 Employee Training 206 - 54

9.0 Facility Work 206 - 59

10.0 Power System and Electrical Installation Security (Locking) 206 - 61

11.0 References 206 - 62


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Appendices

Appendix A Clearance and Approach Boundaries Figures and Tables

Appendix B Limits of Approach

Appendix C Flame-Resistant Clothing Recommendations

Appendix D Sample Calculation of Flash Protection Boundary Dc, Arc in Open Air E ma ,and Arc in Cubic Box E mb

Appendix E Recommended Personal Protective Equipment

Appendix F Work Area Protection

Appendix G Job Briefing and Planning Checklist

Appendix H Energized Electrical Work Permit

Appendix I Substation Project Installation Safety Assessment Checklist

Appendix J Substation Inspection Checklist

Appendix K Electrical Control Room Inspection Checklist

Appendix L Test Procedure for Daily Inspection of Rubber Gloves

Appendix M Safety Tags

Appendix N Grounding Cable and Jumper Ratings

Appendix O Equipotential Grounding Techniques

Appendix P Principles of Electrical Safety

Appendix Q OSHA Regulations (Standards 29 CFR)

Appendix R Sample Procedures for Overhead Electrical Lines and Equipment

Appendix S Example of Flash Protection Labels for Electrical Equipment

Appendix T - Glossary


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1.0 Purpose

Most incidents and injuries related to electrical systems can be avoided by following the safework practices described in this document. In addition to the personal pain of suffering aninjury, incidents can result in lost time, medical costs, equipment damage, production loss,and legal costs.

2.0 Scope

2.1 Provisions and Responsibili ties

This document provides the minimum safety knowledge and procedures that allowindividuals and facilities to work with, or in proximity to, energized high- and low-voltagesources. (In the language of applicable safety standards, this is formally designated to beworking near or working on exposed live parts - See Appendix T - Glossary .) Individualsand facilities, however, are responsible for customizing this information to include detailsand activities specific to their locations.

2.2 Safety Considerations

This practice sets minimum safety rules and safe work recommendations for the design,operation, and maintenance of high- and low-voltage systems throughout Chevron Pipe LineCompany (hereinafter referred to as company) facilities. It is imperative that, at aminimum, these guidelines are met (or exceeded) to enhance employee safety. If more

stringent local governmental codes, accepted employee safety practices, or design criteriaexist, follow those codes or standards.

2.3 Personnel Covered by This Procedure

This document applies to all employees, contractors, and visitors while they are close toenergized conductors, energized exposed parts of electrical equipment, or conductors and equipment that potentially may become energized.

2.4 Activit ies Covered by This Procedure

This practice applies to new or modified high- and low-voltage installations. Existinginstallations need not be physically modified to comply with this document unless qualified

personnel consider the modifications necessary to protect affected persons from recognized hazards.


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Page 206-2 Revised/Printed September 2010, Uncontrolled when printed HES 206 Electrical Safe Work Practice

2.5 References

For the purpose of this practice, low voltage means 1,000 volts nominal or less phase-to- phase or conductor-to-conductor, and high voltage means voltages above 1,000 volts ac, phase-to-phase.

2.6 Limitations and Expectations

Knowledge of this practice by itself does not make a person a qualified electrical worker.Each site should establish guidelines for informal and formal training, as well as the levels of experience needed for workers in the electrical field or other workers whose job functionexposes them to a potential electrical hazard. (NFPA 70E, 110.3; NFPA 70E, 110.6)

3.0 Roles and Responsibil iti es

3.1 Location ManagementThe location manager or his or her designee is responsible for:

Appointing a qualified employee as the location resource who is knowledgeable aboutthe current version of this document and its associated references. The personappointed has the responsibility and authority for implementing this practice.

Designating, if desired, a qualified employee for each functional or operational areathat is responsible for meeting all administrative, design, construction, maintenance,and documentation requirements of this practice. This responsibility includes systemelectrical planning, operation, and control. This person is also responsible for obtaining, reading, understanding/interpreting, implementing, and maintainingmandated (under law) governmental codes, policies, and practices.

Approving the following:o Exceptions to the Live Parts Work Policy

o Energized Electrical Work Permits NFPA 70E, 130.1(A)

o Personal protective equipment (PPE)

o Test equipment

o The decision to barrier and insulate instead of de-energize

3.2 Task Supervisor or Person in Charge (PIC)

(NESC 421A (modified))

This individual should be a qualified employee, (See Appendix T - Glossary ) and isresponsible for:


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adopting precautions that are within the individuals authority to prevent accidents,and taking positive action to obtain necessary precautions for those concerns notwithin the individuals authority to assure employee safety.

ensuring that the site safety rules, training requirements, and operating procedures, ascontained in this or other practices, are observed by the employees under his or her direction.

preparing all the necessary documentation as required (e.g., switching procedures,confined space procedures, digging permits, welding permits, etc.).

preventing unauthorized persons from approaching places where electrical work requiring qualification is being performed.

ensuring that the tools or devices used are suited for the work at hand and thatapplicable tools have been inspected and tested as required.

3.3 Employee

The employee is the person most responsible for his or her own safety.

Qualified and authorized employees should remain knowledgeable about applicableelectrical safety concerns as contained in this practice or other practices.

Affected employees should be aware of electrical hazards, where electrical work is nottheir primary task, but where the opportunity for contact exists (i.e., during lockout/tagout,when working near open crane rails or motor control centers and switchgear, around cableladders, and resetting devices and equipment).

3.4 EscortThe escort is a qualified employee whose responsibility is to safeguard the people in his or her care and to assure that safety regulations are observed.

3.5 Contractors and Visitors

Contractors and visitors are to follow, at a minimum, all safety regulations of this facility ascontained in this practice.

4.0 Safe Work Practices4.1 Live Parts Work Policy


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4.1.1 General Policies

The companys general policy is that NO maintenance or construction/installationwork is performed on any conductors and/or exposed equipment parts at 50 voltsand above while energized. (NFPA 70E, 130.1; OSHA regulation 1910.333(a)(1))

If exposed live parts are not placed in an electrically safe work condition (i.e., for the reasons of increased or additional hazards or infeasibility), work to be

performed is considered energized electrical work and should only be performed as permitted by written permit. The energized electrical work permit could includethe following items:

a) A description of the circuit and equipment to be worked on and their location

b) Justification for why the work must be performed in an energized condition

c) A description of the safe work practices to be employed d) Results of the shock hazard analysis

e) Determination of shock protection boundaries

f) Results of the flash hazard analysis

g) The flash protection boundary

h) The necessary PPE to safely perform the assigned task

i) Means employed to restrict the access of unqualified persons from the

work area

j) Evidence of completion of a job briefing, including a discussion of any job-specific hazards

k) Energized Work Approval (authorizing or responsible management, safetyofficer, or owner, etc.) signature(s)

NOTE: See Appendix H for a sample of an energized electrical work permit.

Work performed by qualified persons on or near live parts related to tasks, such astesting, troubleshooting, voltage measuring, etc., can be performed without anenergized electrical work permit provided appropriate safe work practices and

personal protective equipment are provided and used.


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A hazard/risk evaluation procedure should be used before work is started on or near exposed live parts operating at 50 volts or more, or where an electrical hazard exists. For an example of such a procedure, see Annex F of NFPA 70E -2004.

Electrical equipment and lines should be considered energized unless put in anelectrically safe work condition (i.e., locked/tagged/tried, tested, and grounded in

accordance with section 4.9 and section 4.10 ).

All test equipment used should be approved by location management.

All tools and/or handling equipment that might make contact with exposed live parts should be insulated and of an approved design.

Non-current-carrying metal parts, such as transformer cases or circuit breaker housings, are considered energized to the highest voltage to which they areexposed until they are tested and known to be totally free of voltage, or unlessthey are grounded by an equipment grounding conductor. (NESC 420E[(modified])

While working within reach of exposed live parts, the employee should removeall jewelry and similar conductive apparel if such articles may inadvertentlycontact the exposed live parts. (NFPA 70E, 130.6; OSHA regulation1910.333(c)(8); OSHA regulation 1910.269(l)(6))

When fuses are installed or removed, with one or more terminals within theenclosure energized at more than 300 volts or with exposed parts energized atmore than 50 volts, tools and gloves rated for the voltage should be used. (OSHAregulation 1910.269(l)(7); NESC 420N; NFPA 70E, 130.7(D)(1))

Use only open devices designed to interrupt load current, if the circuit is under load. Test for the absence of load current when opening devices not designed tointerrupt load.

When work is performed in the proximity of covered (non-insulated) wires, thework should proceed using the same precautions as when working with exposed live parts.

Two employees must be present if repair work (see definition of Working On(Live Parts) in Appendix T - Glossary ) occurs inside the limited approach

boundary and a shock hazard exists. One of the two must be qualified and theother either qualified or authorized. (OSHA regulation 1910.269(l)(1)(i))

A shock hazard analysis should be performed to determine the voltage to which personnel will be exposed, boundary requirements, and the PPE necessary tominimize the possibility of electric shock.

A flash hazard analysis is recommended before a person approaches any exposed electrical conductor or circuit part not placed in an electrically safe work conditionto protect personnel from the possibility of being injured by an arc flash. The flash


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protection boundary, and the necessary PPE used by people while working withinthe boundary, is determined during this analysis.

4.1.2 Exceptions to General Policies

All exceptions, other than those listed below, should be approved by the location

manager or his or her designee and require a written documented plan. (NFPA70E, 130.1; FPN 1, 2, and 3; OSHA regulation 1910.269(o)(note))

A qualified person may perform the following simple jobs:o Use glow sticks or other high-voltage detectors

o Attach grounds

o Perform high-voltage phasing

o Take voltage readings

o Use hot sticks for switching operations

Electrical servicing activities (maintenance troubleshooting and diagnostictesting) that must be performed on energized electrical equipment requirethe worker to take special precautions. Such activities covered by this

practice include:o Voltage phasing

o Preventive maintenance observations and meter checks

o System component adjustment

o Voltage readings

o Troubleshootingo Resetting device overloads

When these activities, listed as exceptions, place the worker in close proximity toexposed live parts, appropriate PPE should be used. Such PPE, in addition to theminimum basic PPE requirements for electrical personnel, may include:

A face shield or flash hood.

Insulating gloves with leather protectors.

Flame resistant clothing or flash suit.

(NFPA 70E, 130.2; OSHA regulations 1910.269(l)(2)(i-iii), (L)(6)(i-iii))

The location management is responsible for approving the PPE selection for suchactivities.

4.1.3 Requirements for Live Parts Work


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Before starting any construction work or maintenance work, requiring activitiesother than the exceptions in section 4.1.2 Exceptions to General Policies , that will

place the worker(s) in close proximity to exposed live parts the:

Electrical equipment should be totally de-energized.

Work area should have an appropriate and be insulated.(NFPA 70E, 130.1; OSHA regulation 1910.333(a)(1))

The decision to barrier and insulate instead of de-energizing should be made bythe task supervisor or PIC and approved by the location manager or his or her designee.

Only persons qualified in the techniques required to work on exposed live partsshould do this work. Safety conditions outlined in this practice should be used for all work on or near live parts. (OSHA regulation 1910.269(l)(1))

When persons qualified for live part work must work on exposed live parts, theyshould insulate and use barriers, as appropriate. (NFPA 70E, 130.7(D); OSHAregulations 1910.333(a)(2) and(c)(2); OSHA regulations 1910.269(l)(2)(i-iii) and (l)(3)).

When used, install physical or mechanical (field fabricated) barriers no closer thanthe restricted approach boundary (distance). While the barrier is being installed,maintain the restricted approach boundary distance, or place the exposed live partsin an electrically safe work condition during the barrier placement. (NFPA 70E,130.7(D)(1)(i))

To cross the prohibited approach boundary and enter the prohibited space is

considered the same as making contact with exposed live parts. Any work onexposed live parts should use the procedures defined under Working Inside theProhibited Approach Boundary (see Appendix B Limits of Approach ). (NFPA70E, Annex C C.1.2.4; Appendix A, A-1.2.2-A-1.2.4)


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4.2 Working On or Near Energized Equipment

4.2.1 Hazards

When working on or near energized equipment, there are two primary hazards toconsider:

Flash hazard (relates to the thermal energy of an electrical arc).

Shock hazard.

The following activities could create an electrical arc:

a) Doing any switching with doors open on switchgear or motor starters

b) Installing or removing circuit breakers or motor starter contactors with theswitchgear bus energized

c) Installing or removing combination circuit breaker and motor starter cubicles, commonly referred to as "buckets"

d) Working on motor control centers with open doors (unless the power components at 480 or 600 volts are well guarded) or when removing or installing starters

e) Installing or removing safety grounds

f) Taking voltage measurements

g) Working on exposed live parts

4.2.2 Flash Hazard Analysis and Arc Flash Protective Equipment (NFPA 70E, 130.3)

Flash hazard analysis should be done before a person approaches any exposed electrical conductor or circuit part not placed in an electrically safe work condition.

Establish a flash protection boundary and require all personnel crossing the boundary to wear appropriate arc flash protective equipment. This requirement provides protection from vaporized metal, arc radiation, or hot gases should an arcflash occur on the equipment. (OSHA regulation 1910.269(l)(6)(i-iii))

The size of the flash protection boundary is determined by: The size of the source transformer or the available short-circuit megavolt

amperes (MVA)

The clearing time of the protective device (fuse or circuit breaker)upstream


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Refer to NFPA 70E-2004 section 130.3 to determine the flash protection boundary for a particular application.

NOTE: See Appendix D , sample calculation of flash protection boundary. The flash protection boundary may be calculated byusing the formulas in Appendix D.

4.2.3 Approach Distances

(NFPA 70E, 130.2; OSHA regulation 1910.269(l)(2); (Table A-6 ); OSHAregulation 1910.333(c)(3)(i-ii);(Table 5-5))

The approach distance to exposed live parts varies depending on a persons status: Affected persons (persons who are not authorized or qualified) should

adhere to the limited approach boundary (Ten (10)-Foot Rule) and notencroach on this distance from an exposed live part.

Authorized persons, who are specifically trained for a task, may work inside the limited approach boundary, but should never be allowed to work as close as the restricted approach boundary allowed for a qualified employee, as shown in Appendix A, Table A-6 .

Qualified persons may work up to the restricted approach boundarydistances listed in Appendix A, Table A-6. If a person is working near therestricted approach boundary for an extended period of time, it isrecommended that special precautions such as insulating and barricading

be used.

A covered conductor is considered to have no insulating strength whatsoever and should be treated as a non-insulated, exposed live part for the purpose of determining approach distance.

NOTE: Refer to Appendix B Limits of Approach .

4.2.4 Working on Live Parts

Only persons qualified in the techniques required to work on exposed live partsshould be used for this work. When such a person must work on exposed live

parts, he or she should insulate and use barriers, as appropriate. (OSHA regulation1910.269(l)(1); OSHA regulation 1910.333(c)(2); NFPA 70E, 130.2; Annex CC.1.2)

Any work on exposed live parts should follow the procedures defined inWorking Inside the Prohibited Approach Boundary (see Appendix B Limits of Approach ).


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Crossing the prohibited approach boundary and entering the prohibited space isconsidered the same as making contact with exposed live parts.

4.2.5 Insulated Armored High Voltage Cable

The Ten (10)-Foot Rule does not apply to armored insulated high-voltage cable.

Work activities may be performed adjacent to this type of cable while it isenergized. However, this type of cable should not be disturbed or moved while itis energized without a documented plan approved by the location manager or hisor her designee.

4.2.6 Insulated Non-Armored High Voltage Cable

This type of cable does not have the added protection of armor and the integrity of the insulation should be considered. The approval of the location manager or hisor her designee and a documented plan is recommended before work activitiesthat risk damaging the cable (e.g., tools dropped or swung) may be performed

within 10 of this type of cable while it is energized.

This type of cable should not be disturbed or moved while it is energized.

EXCEPTION: Insulated armored and non-armored high-voltage cables may be moved during special applications such as mining dragline and other moveable substation cables, ship unloader cable reels, and equivalent applications for mobile equipment.

4.2.7 Procedures for Climbing Structures While Working On or Near Live Parts

Fall prevention/protection should be used anytime an employee is working six (6)(180 cm) or more above the ground. Use the following precautions, as well asthose in the facilitys fall protection program (refer to company procedure HES-207, Fall Protection Program):

All small equipment and tools used aloft should be raised and lowered using a handline, a canvas bucket, or other suitable container.

Employees working overhead should take precautions to prevent tools or material from dropping and falling.

Employees on the ground should stay clear of overhead work to reduce the potential of being struck by falling objects.

(OSHA regulations 1910.269(g)(2) and Part 1926, subpart E)


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4.2.8 Live Parts Operating at 50 Volts or More

Electric lines and equipment should be considered energized unless they have been put in an electrically safe work condition, i.e., locked out or tagged out,tested for the absence of voltage, and grounded as required in this practice.

Operating voltages of equipment and lines should be determined before work isdone on or near energized parts. (NFPA 70E, 130.1)

Only qualified employees may work on, near, or in an area where exposed live parts operate at 50 volts or more.

Two qualified employees should be present to perform the following types of work:

Installation, removal, or repair of lines that are energized at more than 600volts

Installation, removal, or repair of de-energized lines if there is exposure tocontact with other parts energized at more than 600 volts

Installation, removal, or repair of any other equipment if the employee isexposed to parts energized at more than 600 volts

Work that uses mechanical equipment (other than insulated aerial lifts)near parts energized at more than 600 volts

(OSHA regulation 1910.269(l)(1)(i))

Two qualified employees do not need to be present to perform the following work functions:

Routine switching if employer verifies that site conditions allow thisfunction to be performed safely

Work using live-line tools, as long as the employee cannot make contactwith exposed live parts through inadvertent reach

Emergency repairs to the extent necessary to safeguard the general public

(OSHA regulation 1910.269(l)(1)(ii))

4.2.9 Insulating the Worker from Exposed Live Parts

Unless an approved insulating handle is used, no employees may approach or takeany conductive object closer to exposed live parts than the distances shown inAppendix A, Table A-6 except when:

The employee is insulated from the energized part. (Insulating gloves or insulating gloves and sleeves, rated for the voltage, are considered to beinsulation of the employee only from the energized part upon which work is being performed).


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The energized part is insulated from the employee and any other conductive object at a different potential.

The employee is insulated from any other exposed conductive objects at adifferent potential.

(NFPA 70E, 130.2(C); OSHA regulation 1910.269(l)(2))If insulating gloves are used to insulate the employee from the exposed live parts,insulating sleeves should also be used. However, sleeves are not required if:

Exposed live parts are insulated from the employee and these parts are not being worked upon.

The insulation is placed without exposure to the employees upper arms or to other exposed parts.

(OSHA regulation 1910.269(l)(3))

Employees may not enter any space that contains exposed live parts unlessadequate illumination is provided. (OSHA regulation 1910.333(c)(4); NFPA 70E,130.6(C))

The employer should assure that, to the extent that other safety-related conditions permit, the employee works in a position so that a slip or shock will not bring theemployee into contact with exposed live parts.

When an employee works in a confined or an enclosed space that containsexposed live parts, insulating materials, such as protective shields or barriers,should be used to prevent inadvertent contact. (NFPA 70E, 130.6 (F); OSHAregulation 1910.333(c)(5))

4.2.10 Working On or Near Installations Not Related to Power Generation, Transmissionand Distribution Insulated Tools and Insulating Gloves

The following applies to working on or near exposed live parts in installations notrelated to power generation, transmission, and distribution:

Employees should use insulated tools or handling equipment if the tools or handling equipment might make contact with such conductors or parts.

Tools used should be rated for the voltage involved. Commerciallyavailable insulated hand tools (pliers, screwdrivers) are typically rated up

to 1,000 volts ac.

(NFPA 70E, 130.7(D)(1); OSHA regulation 1910.335(a)(2)) Employees should wear insulated gloves with leather protectors. (NFPA

70E, 130.6(C)(6) and 130.7 (C)(13(c); 130.7(C)(6))


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EXCEPTION: If working on exposed live parts of circuits rated 50 through 300 volts (phase-to-phase), insulating rubber gloves are not required when all of the following conditions are satisfied:

Fine dexterity is necessary for the task.

Any insulated hand tools, test instruments and equipment, test probes, test clips, and test leads required

for the task are visually inspected for external defects and damage prior to each use.

The work on the exposed live parts does not expose theworker to accidental contact with other exposed live

parts in the vicinity of the task.

Leather gloves are used if necessary for arc flash protection.

NOTE: This exception does not apply to working on 277 volt phase-to-neutral circuits, since the system

phase-to-phase voltage rating is 480 volts(480Y/277 volts, three-phase, four-wire).

4.3 Equipment/Line Status

4.3.1 Basic Rule

Electrical equipment and lines should be considered energized until put in anelectrically safe work condition, i.e., disconnected from energized parts, tested,locked out and/or tagged out, and grounded in accordance with section 4.9Lockout/Tagout and section 4.10 Grounding. (NFPA 70E, 130.1; OSHAregulation 1910.269(l)(1); OSHA regulation 1910.333(a)(1))

4.3.2 Proper Work Environment

The preferred approach is to de-energize.

Equipment to be worked on should normally be tested, de-energized, locked outand tagged out according to established practices.

While low voltages do not typically require the formalized procedures and writtenswitching instructions required for high-voltage work, a disciplined, analyzed

procedure should be followed.

If the work to be done is extensive and complex, a formal written switching order should be followed to de-energize and lockout the equipment.


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Identify all potential voltage sources and make plans to positively control allconductors and isolating devices. Additionally:

a) Determine all possible voltage sources; check all drawings, diagrams,identification tags, etc.

b) Interview individuals familiar with the facility.c) Interrupt all load current and then open isolation devices.

d) Where possible, visually verify open disconnects.

e) Apply lockout/tagout devices according to procedure.

f) Use voltage detection devices adequately rated for the situation and determine that the voltage detector is operating properly before and after each test.

g) Apply ground connection devices rated for the available short-circuit duty

where: Conductors could become energized. Induced or stored energy could exist. The de-energized conductors could be contacted by energized

conductors.

(NFPA 70E, 120.1)

4.3.3 Testing and Verification Techniques for Isolation

Consider all circuits energized until a voltage test positively verifies them as de-energized. Use the test before touch concept. (NFPA 70E, 120.2(F); NFPA 70E120.1)

Recognize that after no voltage is verified, voltage can reappear on a de-energized system through such events as:

a) Backfeeds from voltage transformers or control power transformers.

b) Undocumented alternate sources.

c) Missed lockouts.

d) Equipment not operating at the time of test.

e) Lightning.

f) Induced voltage.

g) Energized line contacting a de-energized line.

h) Insulation failure.


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The following testing and verification techniques are recommended:

a) Test for absence of voltage on molded-case circuit breakers (1,000 voltsand less) because they cannot be visually verified.

CAUTION: Test for voltage both phase-to-ground and phase-to-phase.

b) Purchase panel boards (1,000 volts and less) pre-equipped with lockingdevices and use these devices for lock out.

c) Remove fuses from low-voltage switches that have covered blades, if applicable, after verifying there is no voltage.

d) Withdraw draw-out circuit breakers to the farthest position in the cubicle(with the line and load stabs disconnected) and completely remove thecircuit breaker if a ground-and-test device will be applied. (NFPA 70E,120.1)

e) Remove high-voltage motor starter (sometimes referred to as NEMA E2starter) contactor assemblies completely from their cubicles, to avoid accidental rolling of the contactor truck back onto the contact stabs.

f) Open isolation disconnects on circuit breakers within open-air switchyards. Remove any fuses for additional isolation.

g) Do not rely on control circuit isolation for lockout purposes. Provide primary circuit isolation on circuit breakers and motor starters (i.e.,withdraw, or rack out, circuit breakers or open disconnect switches).(OSHA regulation 1910.269(x)"Energy isolating device")

Any voltage testing procedure should include the following considerations: What voltage detector will be used and what will be done to verify proper

operation of the voltage detector before and after use.

A requirement to define the boundary of the work area. A requirement to test before touching every exposed conductor or circuit

part(s) within the defined boundary of the work area.

A requirement to retest for absence of voltage when circuit conditionschange or when the job location was left unattended.

Where there are no accessible exposed points to take voltagemeasurements, planning considerations must include alternate methods of verification.


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4.4 De-energizing/Re-energizing Lines and Equipment for Employee Protections

4.4.1 De-energizing Lines and Equipment (NFPA 70E, 120.1)

Verify an electrically safe work condition using the following process:a) Determine all possible sources of electrical supply to the specific

equipment. Check applicable up-to-date drawings, diagrams, and identification tags.

b) After properly interrupting the load current, open the disconnectingdevice(s) for each source.

c) Where it is possible, visually verify that all the blades of the disconnectingdevices are fully open or that draw-out-type circuit breakers are fullyremoved from cubicles.

d) Apply lockout/tagout devices in accordance with a documented and established policy.

e) Use an adequately rated voltage detector to test each phase conductor or circuit part to verify that they are de-energized. Before and after each test,determine that the voltage detector is operating satisfactorily.

f) Where the possibility of induced voltages or stored electrical energy exists,ground the phase conductors or circuit parts before touching them.

g) Where it could be reasonably anticipated that the conductors or circuit parts being de-energized could contact other exposed energized conductorsor circuit parts, apply ground-connecting devices rated for the availablefault duty.

h) Establish a work zone in accordance with section 4.8 Work Zone.

4.4.2 Re-energizing Lines and Equipment (OSHA regulations 1910.269(m)(3)(xiii);OSHA regulation 1910.269(m)(3)(x);OSHA regulation 1910.333(b)(2)(v))

Before re-energizing lines and equipment, complete the following steps: Remove all protective grounds.

CAUTION: Grounds left on equipment when re-energized present a short circuit hazard. A positive method of control should be used to assure removal before re-energizing (tags, leaving doors or covers open, leaving the ground cables clearly visible, use of magnetic ground signs, etc.).

Remove all personal safety locks and tags from points of disconnect.


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Clear all employees away from the lines and equipment. Re-energize lines and equipment following the facilitys procedures.

4.5 Power System Switching Procedures

4.5.1 Preparation

Written Switching Order (NFPA 70E, 130.1)

A written switching order is recommended before any switching is performed onthe high-voltage distribution power system (this recommendation does not includeswitching of individual motors). The switching order should be:

Written by a qualified employee. Reviewed by at least one other qualified employee. Signed and dated by both people before it is used.

See Appendix H for a sample Energized Electrical Work Permit form.

4.5.2 Job Briefing for Switching Procedures (NFPA 70E, 110.7)

Hold a job briefing before starting any switching. The PIC of the switching order and all employees involved in the switching should attend.

At a minimum, review the following items:

a) The reason switching is being performed

b) One line drawing and/or power system status board to assure that allinvolved understand what will occur

c) Each step of the switching order

d) The job assignments for all involved (who will do what)

e) Safety issues and required PPE

f) If required, review the:o Electrical clearance requirements and/or lockout/tagout issues.

o Location of safety grounds to be installed or removed and bywhom.

o Other issues (such as operational limitations).

4.5.3 During Switching


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During switching, follow the written switching order in the order the steps arewritten, check off each switching step when completed, and record the time of completion.

The following switching procedures are recommended:

a) The person receiving a switching command repeats the switchingcommand and confirms it with the person issuing the order beforeexecuting the command.

b) If switching commands are given by radio, use a unique switchingchannel. Cross-talk on the radio during switching could cause a switchingerror.

c) When the switching is complete, document the status of the power system.Use of a status board or pin board is one method of accomplishing this.

d) Document information on power system abnormalities to inform off-shift

personnel who may be involved in responding to power system problems.Post this information near a power system status board or pin board.

e) Post any issues involving open electrical clearances (or parts of the power system under lockout/tagout), the location of any safety grounds, and other

power system safety issues near the power system status board or pin board.

f) A second person stands clear and acts as a safety observer for the persondoing the switching. The safety observer assures that each step the switchoperator is about to perform is correct.

4.5.4 Job Briefings Prior to Work (NFPA 70E, 110.7; OSHA regulation1910.269(c)(1,2,3))

The PIC should conduct a job briefing before starting work on new installationsand modifications to existing installations.

He or she should conduct at least one job briefing before the start of each shift.Hold additional job briefings if changes occur during the course of the work thatcould affect personnel safety.

The job briefing includes the following at a minimum:

a) Hazards associated with the job

b) Work procedures involved

c) Special precautions

d) Energy source controls

e) PPE requirements


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f) Work zones

During the job briefing, each person involved should ask himself or herself thefollowing questions prior to starting the task:

Do I thoroughly understand the job?

Do I thoroughly understand my role and everyone elses role in the job? Am I aware of all the hazards I may possibly encounter? Am I knowledgeable about all safety rules and required personal protective

equipment applicable to this job?

Do I have safeguards in place to protect me from unexpected events?

A brief discussion is satisfactory if the work involved is routine and if theemployee, by virtue of training and experience, can reasonably be expected torecognize and avoid the hazards involved in the job.

A more extensive discussion is needed if the: Work is complicated or particularly hazardous. Employee (qualified or unqualified) cannot be expected to recognize and

avoid the hazards involved in the job.

As work progresses during the day after the initial job briefing, a person workingalone should plan and review his or her work as if a briefing were held beforeeach task.

Refer to the Job Briefing and Planning Checklist in Appendix G .

4.6 Personal Protective Equipment

(OSHA regulation 1910.269(g) subpart I; OSHA regulation 1910.132-138; OSHA regulation1910.335; NFPA 70E 130.7 and Table 130.7(C)(8))

The following PPE is recommended for protection from arc flash and shock hazards. SpecificPPE requirements will be designated during the job briefing before start of each job. (See theHazard Risk Category Classifications table in Appendix C.)

Recognizing that incident energy increases as the distance from the arc flash decreases,additional PPE is recommended for any parts of the body that are closer than the distance at

which the incident arc flash energy may have been determined. (NFPA 70E, 130.3(B))4.6.1 Clothing/Apparel

The employer should assure that employees who are exposed to exposed live partsare trained in the hazards of arcs and flames of arcs. (OSHA regulation1910.269(l)(6)(iii); NFPA 70E 130.3 (B), 130.7 Clothing/Apparel)


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Wear approved safety glasses with non-conductive sideshields at all times whenworking with or in close proximity to potentially energized conductors or exposed non-insulated parts. (See ANSI Z87.1).

Goggles and/or arc-rated face shields may also be needed for the task.

4.6.4 Hand Protection

Wear leather gloves for arc-flash protection when insulating rubber gloves are notapplicable. (NFPA 70E 130.7 (C)(13)(c))

Always use insulating rubber gloves with leather protectors (when required for shock protection) in the following situations:

When working on energized, or potentially energized, conductors or equipment

As an added means of protection any time while using live-line tools or test probes

During the installation or removal of safety grounds

(NFPA 70E, 130.7 (C)(6); ASTM D 120)

EXCEPTION: If working on exposed live parts of circuits or systems rated 50 through 300 volts (phase-to-phase), insulating rubber gloves may not be needed when all of the following conditions are satisfied: Fine dexterity is required for the task.

Any insulated hand tools, test instruments and equipment, test probes, test clips, and test leads required for the task are visually inspected forexternal defects and damage prior to each use.

The work on the exposed live parts does not expose theworker to accidental contact with other exposed live

parts in the vicinity of the task.

Leather gloves are used, if necessary, for arc flash protection.

NOTE: This exception does not apply to working on 277 volt phase-to-neutral circuits, because the

system phase-to-phase voltage rating is 480 volts(480Y/277 volts, three-phase, four-wire).


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(130.8(C)(12)(f) )

Only use gloves that have been dielectrically tested within the previous six (6)months. (ref. ASTM F496) (OSHA regulation 1910.137(b)(2)(viii))

Inspect and air test gloves before each use and immediately following any incidentthat can reasonably be suspected as having caused damage. Air testing is

performed by trapping air in the glove and examining for pin hole or other apparent leakage (see Appendix L - Test Procedure for Daily Inspection of Rubber Gloves ) (ASTM F496).

Store gloves in an approved glove bag or an equivalent protective location. If possible, store gloves with the cuffs down.

Do not exceed the rating on the glove as shown in Table 1 .

TABLE 1: Insulating Rubber Glove Ratings

Insulating Rubber Gloves

Class Maximum Use Voltage(AC)

Test Voltage (AC)

00 500 volts 2,500 volts

0 1,000 volts 5,000 volts

1 7,500 volts 10,000 volts

2 17,000 volts 20,000 volts

3 26,500 volts 30,000 volts

4 36,000 volts 40,000 volts

4.6.5 Hearing Protection (NFPA 70E 130.7 (C)(10))

Because electrical faults can result in intense sound levels, hearing protection inthe form of ear canal inserts should be used. See Appendix C, Table C-2 .

4.7 Tools

(NFPA 70E 130.7 (D); ASTM F711)

4.7.1 Live-line Tools (OSHA regulation 1910.269(j))


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Store live-line tools in a clean and dry location. Live-line tools should not be placed on the ground.

Wipe clean each live-line tool and visually inspect it for defects before use eachday. If, after wiping, the tool has contaminants that could affect its insulatingqualities or if its mechanical integrity is questionable, remove the tool from

service and have it repaired.

Following repair, retest the tool using the testing program procedures described below.

Testing Procedure (OSHA regulation 1910.269(j)(2)(iii))

Remove each live-line tool from service at least every two years and administer the following examination and tests:

a) Thoroughly examine the tool for defects.

b) If defects or contaminants that could affect the insulating qualities or mechanical integrity of the tool are found, the tool may be repaired and refinished or permanently removed from service.

c) If no defects are detected and no contaminants found, clean and wax thetool using only a wax approved for live-line tools.

d) Use a test method that tests the entire working length of the tool.

e) Tools made of fiberglass-reinforced plastic (FRP) should be tested withwet conditions applied over the entire working length of the tool.

f) If the tool is made of FRP, the test consists of applying 100,000 volts per foot (30 cm) of length for five (5) minutes. (ref. IEEE 978) (OSHAregulation 1910.269(j)(1)(I); IEEE Std. 978)

g) Other high voltage tests are acceptable if the employer can demonstratethat these are equivalent (such as IEEE Std. 978-1984).

4.7.2 Cord-connected Hand and Portable Power Tools

Use ground fault circuit interrupters when using cord-connected portable power tools or other cord-connected equipment. (NFPA 70E, 110.9 (B)(3))

Visually inspect cord-connected portable power tools, extension cords, and other cord-connected equipment before each use. Periodically inspect all extensioncords.

Observe the following precautions for any cord- and plug-connected equipmentnot supplied by premises wiring:

Use a tool equipped with a cord containing an equipment-groundingconductor connected to the tool frame and to a ground at the other end (if


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e) Assure that pressure is released before connections are broken, unlessquick acting, self-closing connectors are used. Do not kink hoses.

Employees may not use any part of their bodies to locate or attempt to stop ahydraulic leak.

4.7.4 Ladders and Platforms

(OSHA regulation 1910.21 through 30)

Use ladders and platforms that comply with Subpart D of 1910. Ladders and platforms should be:

Properly secured to prevent their dislodgement. Used only in applications for which they were designed. Capable of supporting without failure at least 2.5 times the maximum

working load.

Non-conductive when used for electrical tasks.

Do not exceed the working load for which the ladder or platform was designed.

4.8 Work Zone

Work zones may be needed to safeguard personnel from potential hazards. Use barricades, inconjunction with safety signs, to limit or prevent access to work areas where hazards mayexist. (NFPA 70E, 130.7 (E); OSHA regulations 1910.269(l)(2). (u)(4), (o)(3))

In some instances, it is appropriate to barricade or otherwise identify a work area as

containing electrical hazards not normally encountered during routine operation of theequipment and/or conductors. This process would normally be the case during maintenanceor renovations to existing installations and additions to installations where electricalequipment and/or conductors are located. Appropriate identification alerts employees of thehazards in their work areas. (OSHA regulations 1910.335(a)(2)(ii) and 1910.335(b))

4.8.1 Electrical Hazard Barricade Tape/Rope

Electrical hazard barricade tape/rope is used as a temporary hazard warning. Temporary means the duration of any work assignment where there is an

active effort to complete a permanent installation and employee safety is

not compromised by hazards other than electrical ones (e.g., a fallinghazard also exists).

Red is the recommended color. The red tape should be imprinted with wording such as Danger - Do not

Enter.

4.8.2 Area Protection


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Areas Accessible to Qualified Employees Only

Qualified employees should: Determine the size of the work zone. Consider the types and size of conductive materials and equipment to be

used in the area. Determine the limited approach boundary (Appendix A, Table A-6 ). Determine the flash protection boundary.

If the work exposes energized or moving parts that are normally protected: Display danger signs. Erect suitable barricades to restrict other personnel from entering the area.

When working in a restricted section that borders other sections (i.e., a portion of a substation, one section of switchgear, a row of transformers or breakers, or one

panel of a switchboard), a qualified employee should: Mark the work area conspicuously. Place barriers to prevent accidental contact with exposed live parts in

adjacent sections.

NOTE: Use designated work zones around look alike equipment.

Areas Accessible to Vehicular and Pedestrian Traffic

Use appropriate warning signs and barricades where vehicles and non-qualified pedestrian traffic may pass adjacent to electrical equipment that is under maintenance, operating, or under construction, and the safety of these vehicles and

pedestrians could be compromised.

4.8.3 Enclosed Spaces

These recommendations apply only to enclosed spaces, such as manholes,unvented vaults, tunnels, etc., that can be entered by employees. All other confined spaces as defined by OSHA are covered by 29 CFR 1910.146 (OSHAregulations). (NFPA 70E, 130.6 (F); NESC 423)

Assure that employees use safe work practices for entry into and work withinenclosed spaces and for rescue of employees from such places. If hazards remainafter the precautions taken for enclosed space or if the escape procedures cannot

be met, follow the permit-space or confined space requirements of 29 CFR 1910.146. (OSHA regulation 1910.269(e); OSHA regulation 1910.146)

Employees who enter enclosed spaces or serve as attendants should be trained inthe following:


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The hazards of enclosed space entry Enclosed space entry procedures Enclosed space rescue procedures

(OSHA regulation 1910.269(e)(2))

Employees should be provided equipment to assure prompt and safe rescue.

Before removing any entrance cover to an enclosed space: Check for atmospheric pressure and temperature differences. Determine whether there is a hazardous atmosphere in the enclosed space. Eliminate any conditions that make it unsafe to remove the cover.

(OSHA regulations 1910.269(e)(3), (e)(4))

After removing the cover to an enclosed space, guard the opening with a railing or a temporary cover/barrier. Such precautions help prevent an employee or objectsfrom falling into the enclosed space and causing injury.

Hazardous Atmosphere in an Enclosed Space

Before an employee enters the space, test the internal atmosphere for: Oxygen deficiency. Flammable gases and vapors.


For each test, use a direct-reading meter that can collect and immediately analyzedata samples, thus eliminating the need for offsite evaluation. Keep all testequipment, used to monitor atmosphere in enclosed spaces, calibrated properly.(OSHA regulation 1910.269(e)(8))

CAUTION: Use only test devices approved as intrinsically safe.

Do not enter an enclosed space that contains a hazardous atmosphere (confined space hazardous atmosphere). See the requirements of 29 CFR 1910.146. (OSHAregulation 1910.146)

While work is being performed in the space, if there is reason to believe that anyhazard may exist in the space or that traffic may cause a hazardous condition, anattendant with first aid training should be immediately available to render emergency assistance. This attendant may perform tasks outside the enclosed space. (OSHA regulation 1910.269(e)(7))

If flammable gases or vapors are present above a safe level or an oxygendeficiency exists, use forced air ventilation to maintain a safe level of oxygen and


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prevent the accumulation of flammable gases or vapors from reaching a hazardousconcentration. (OSHA regulation 1910.269(e)(11))

If flammable gases or vapors are at a safe level, forced air ventilation may bewaived, providing there is continuous monitoring to assure that there is noincrease of either.

Continuous forced air ventilation should: Be applied for a long enough period before workers are allowed to enter

the enclosed space. This process will assure that a safe atmosphere exists.

Be directed to the employees immediate area. Continue until all employees have left the enclosed space.


The supply for the continuous forced air ventilation should come from a cleansource so that it does not contribute to the hazard in the enclosed space.

Use of Open Flames in an Enclosed Space

If using open flames in the enclosed space, test for flammable gases or vaporsimmediately before using the open flame device and at least once each hour whilethe device is being used in the enclosed space. If there is an indication that one-hour periods are insufficient, test more frequently.

NOTE: Use local Hot Work procedures if open flames are used.

4.8.4 Underground Electrical Facilities (OSHA regulation 1910.269(t))

The following recommendations for work on underground electrical installationsin manholes and/or vaults are in addition to the recommendations for enclosed spaces discussed above:

a) Use ladders or other climbing devices to enter or exit manholes or subsurface vaults that exceed four (4) (122 cm) in depth.

b) Do not use cables or hangers as steps to climb in or out of manholes and vaults.

c) Check equipment used to lower materials and tools for weight supportcapabilities and defects before use.

d) Stand clear of the area directly underneath openings while tools or materials are lowered or raised.

e) Assure that an employee capable of rendering emergency assistance is onduty in the immediate vicinity of the manhole opening. Appropriatetraining for the attendant includes cardiopulmonary resuscitation (CPR),


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first aid, hazards of enclosed space entry, enclosed space entry procedures,and enclosed space rescue procedures.

f) Make sure that all employees are in constant communication. Thiscommunication can consist of visual, voice, or signal line communication.

g) Permit an employee to enter if the nature of the visit does not involve theenergized cables or equipment, but it is for housekeeping, inspection,meter reading, or similar activities. This entrance is permitted only if allconfined space entry requirements are met and the task can be done safely.

h) Provide rescue equipment at the work site to assure the prompt and saferescue of employees from the enclosed space. Rescue equipment includesa mechanical device to retrieve personnel, a full body harness (wristletsmay be used in lieu of the harness), and a retrieval line.

i) If using pulling tapes, install them in the direction that presents the leastamount of hazard to employees. Station an employee at the far end of theduct line to assure that required minimum approach distances aremaintained to protect employees. (OSHA regulation 1910.269(t)(4))

j) Move an energized, armored, insulated, high-voltage cable only after thelocation manager or his or her designee has approved a documented plan.

k) Be sure to move an energized, insulated, low-voltage cable only under thedirect supervision of a qualified employee and while using insulatinggloves.

l) Before proceeding, inspect any cable to be moved for defects, usingappropriate PPE. See Appendix C for PPE requirements.

NOTE: Consider the special hazards of an arc flash event in a confined space before a task is planned. In general, cables connected to a solidly grounded power system represent a greater arc flash hazard than cables (especially single- conductor cables) connected to a resistance-grounded power system.

m) Exact identification is required by electric means unless identification isobvious when multiple cables are present. Protect all other cables not

being worked on against damage.n) Maintain sheath continuity while work is performed on buried cable or on

cables in manholes or treat the sheath as energized. (OSHA regulation1910.269(t)(8))

(OSHA regulation 1910.269(t)(1), (t)(2), (t)(3))

Any of the following conditions can cause cables to be defective:


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Oil or compound leaking from cable or joints Broken cable sheaths Broken joint sleeves Hot surface temperatures Joints swollen beyond normal tolerances

(OSHA regulation 1910.269(t)(7)(note))

When any one of these conditions occurs, employees are NOT permitted in themanhole while the cable is energized. However, if de-energizing the cable is not

possible, protect employees against potential hazards by shields or barriers that arecapable of containing the adverse effects of a fault in the joint.

When cutting cable, ground both ends where practical. Use a cable penetrator tool(such as A. B. Chance companys catalog number C600-1625) to penetrate the

insulation at the point of the cut if the cable cannot be visibly traced from the point of the cut to one of the two ends.

4.8.5 Trenches and Excavation (OSHA regulations 1910.269(f), Part 1926, subpart P,1926.652(a)(ii))

Refer to company procedure HES-202, Excavation.

NOTE: Safe trenching and excavation operations are covered in 29CFR 1926.650, 1926.651, and 1926.652.

4.9 Lockout/Tagout (NFPA 70E 120.2 &110.4 , OSHARegulations 1910.269(d), 1910.147)

Refer to company procedure HES-203, Lockout Tagout.

4.10 Grounding

Use approved clothing (see Appendix C - Flame Resistant Clothing Recommendatio ns),rubber gloves with protectors, hard hat, and eye protection when testing for voltage and

placing/removing grounding devices. (NFPA 70E 130.7 (C)(9)(a))

Use visible maintenance grounds (of adequate size to withstand the available short circuitcurrent, see Appendix N ) to assure that the conductors tested as de-energized remain safe.(NFPA 70E, 120.3; OSHA regulation 1910.269(n)(4); ASTM F855)


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CAUTION: Grounds left on equipment when re-energized present a short- circuit hazard. Use a positive method of control to assure removal before re-energizing (tags, leaving doors or covers open, leaving the ground cables clearly visible, use of magnetic ground signs, etc.).

(OSHA regulation 1910.269(n) "Grounding for the protection of employees")

Apply grounds as if the circuit was energized. Insulated cables can retain a capacitive chargeand open wire lines can have induced voltageboth represent a shock hazard.

Attach the conductor connected to the ground (of a grounding cluster) first and remove it last.

4.10.1 Special Precautions Disconnect all auxiliary devices, such as voltage transformers or control

power transformers, by removing all fuses (primary and secondary) or byracking out.

Account for and remove all grounds before re-energizing. Be aware of other voltage sources when isolating motor-starter circuits. Remember that motor space heaters are usually supplied from foreign

voltage sources.

4.10.2 Parts that Require Grounding

Grounding should be required as final protection against backfeeds on all: Switchgear buses Feeders from substations Open wire lines

Ground all motors equipped with power factor correction capacitors. Additionally,ground all motor circuits above 600 volts before working on the motor. Use aswitchgear ground and test device, or connect grounds at the load-side cableconnections of the circuit breaker or starter.

4.10.3 Special Situation -- Ungrounded Systems

Test for voltage, both phase-to-ground and phase-to-phase, before applyinggrounds.


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4.10.4 Cable Cutting

Ground both ends where practical. Use a cable penetrator tool (such as A. B.Chance companys catalog number C600-1625) to penetrate the insulation at the

point of the cut if the cable cannot be visibly traced from the point of the cut to

one of the two ends.

4.10.5 Traditional Methods

This section describes the procedure for grounding transmission and distributionlines and equipment:

a) Before work on lines or equipment designated as de-energized, issue aclearance that all isolating points have been locked and tagged and appropriate safety grounds have been installed, as detailed in this section.(For exceptions, see section 4.10.6.) (NFPA 70E, 120.1, 120.2(F)(2)(g);

OSHA regulation 1910.269(d)(2)) b) Before any ground is installed, first test the lines or equipment for absence

of voltage unless a previously installed ground is present. (OSHAregulation 1910.269(n)(5))

c) Before installing grounds, visually inspect the grounding equipment toconfirm the equipments integrity.

d) Install temporary protective grounding equipment at the work location.(OSHA regulation 1910.269(n)(3); NFPA 70E, 120.3)

e) If installation of grounds at the work location is not feasible, installgrounds on each side of the work location as close to the work location as

possible.

f) Single-point grounding (equipotential grounding, see section 4.10.9 ) is anacceptable means of grounding.

g) Ground static capacitors (surge protection capacitors and power factor correction capacitors) before working on them even if there is no

possibility of their becoming energized. Wait five minutes betweenisolating the capacitor and applying the grounds.

CAUTION: Grounds left on equipment when re-energized present a short- circuit hazard. Use a positive method of control to assure removal before re-energizing (tags, leaving doors or covers open, leaving the ground cables clearly visible, use of magnetic ground signs, etc.).

4.10.6 Grounding Previously Energized Part


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Before grounding any previously energized part: First connect one end of the grounding device to an effective ground. Next, test the previously energized parts for voltage. If the parts are free from voltage, the grounding may be completed.

(OSHA regulation 1910.269(n)(6))

Using live-line tools, bring the grounding device into contact with the previouslyenergized part and securely attach it. Then:

If the test indicates that the parts are not free from voltage, DO NOT attachthe grounds to the part.

Determine the source of the voltage to assure that the presence of thisvoltage does not prohibit completion of the grounding.

4.10.7 Removing Grounds

Grounds may be removed temporarily for testing. During the test procedure,consider the previously grounded lines and equipment as energized.

When removing grounds: First remove the grounding devices from the de-energized parts using live-

line tools.

Next, remove the connection to the ground.

(OSHA regulation 1910.269(m)(7))

CAUTION: Take extreme caution. If the connection to the ground is removed first before the connection to the de-energized part,electric shock and injury may result.

4.10.8 Protective Grounding Equipment

Protective grounding equipment should be capable of conducting the maximumground-fault current that could flow during the time necessary to clear the fault.This equipment should have an ampacity greater than, or equal to, that of no. 2/0AWG copper. A larger conductor size may be required for higher capacity

systems.An important characteristic of protective grounds is that the impedance to ground

be low enough to guarantee prompt operation of protective devices. This processassures minimum exposure in case of accidental line or equipment tenderization.(OSHA regulation 1910.269(n)(4); NFPA 70E, 120.3 (D))

See Appendix N for information on grounding cable and jumper ratings.


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4.10.9 Equipotential Grounding

Equipotential grounding is a technique used in transmission and distribution lines.Different methods include single-point, double-point, remote double-point, and

personal grounding. These grounding techniques require much skill. Before usingthese methods, complete hands-on training and receive qualification.

Single-point grounding occurs when a worker connects all three phases together with jumpers and then attaches the phases through a single jumper to a cluster bar.The cluster bar is attached to the pole below the workers . The cluster bar isconnected by a jumper to the neutral conductor, if available. If a ground faultshould occur, the worker will be at the same voltage as the lines and currentshould not flow through his or her body.

Double-point grounding is necessary if work at the pole involves breaking thecircuit. It is necessary to ground sources that may come from either direction. The

phases are connected to each other, on both sides of the worker, to the cluster bar

below the workers feet and to the neutral.Remote double-point grounding allows the worker more movement between the

jumper sets, but offers less protection than other methods. The grounds areconnected to structures, such as towers, on each side of the work location. In thiscase, fault current would flow through the towers into the earth. With this method,it is still possible to have potentially fatal current flow through the workers body.It is not recommended unless additional safeguards are taken (see PersonalGrounding, below).

Personal grounding is where a jumper connects the conductor being worked on tothe cluster bar and to the neutral. These can be installed quickly and may be used in addition to remote grounding when full three-phase grounding at the work siteis inappropriate.

NOTE: See Appendix O for figures that illustrate equipotential grounding.

4.10.10 When Grounding is Impractical or Presents a Hazard

The following are exceptions to use of grounds: Grounding is impracticable. Grounding would present greater hazards. There is no possibility of contact with another energized source. Hazard of induced voltage is not present.


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If the employer can demonstrate that the installation of grounds is impractical or presents a greater hazard, the lines or equipment may be considered as de-energized if ALL of the following conditions are met:

Lines have been de-energized as specified in section 4.4 . There is no possibility of contact with another energized source. There is no possibility of induced voltage.

(OSHA regulation 1910.269(n)(2))

4.11 Mobile Equipment Operation

4.11.1 In General

Inspect the critical safety components of mechanical elevating and rotatingequipment before use on each shift. Check the lower and upper controls to assurethey are functioning correctly. Follow the manufacturers recommended checklistfor the inspection. (OSHA regulation 1910.269(p)(1)(i))

No vehicular equipment with an obstructed view to the rear can be used for off-highway job sites, unless one of the following provisions is met:

The vehicle has a reverse signal alarm louder than the surrounding noiselevel.

A designated employee signals that it is safe to make movements.

(OSHA regulation 1910.269(p)(1)(ii))

Heavy equipment, with or without attachments, should have rollover protectionthat meets the requirements of 29 CFR 1926, Subpart W. (OSHA regulation1910.269(p)(1)(iv))

Use lifting equipment within its maximum load rating. (OSHA regulation1910.269(p)(3))

When a suspended load creates a hazard for any other employee, the mobileequipment operator may not leave his or her position at the controls. (OSHAregulation 1910.269(p)(1)(iii))

If a mobile equipment operator notices that operating the equipment may place it

to within 10 (305 cm) of energized or potentially energized conductors or circuit parts of electrical equipment, he or she should notify the appropriate locationmanagement and wait for further safety instructions. (OSHA regulation1910.269(p)(4) minimum approach distance)

When potential exposure to electrical hazards can reasonably be anticipated before the job assignment starts, notify contractors and location employees before


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the mobile equipment is moved to the job site. This notification is theresponsibility of location personnel.

4.11.2 Outrigger-equipped Vehicles

Operate outrigger-equipped vehicles with outriggers extended and firmly set to

provide stability. (OSHA regulation 1910.269(p)(2))

Outriggers may not be retracted or extended beyond the clear view of the operator,unless all employees are outside the range of possible equipment motion.

If the work area or terrain prohibits full use of outriggers, operate the equipmentaccording to the manufacturers specifications for operation without outriggers.

4.11.3 Operator Training

Mobile equipment operators not qualified in electrical work need the followingtraining if their equipment has the potential of coming as close as 10 (see theTen (10)-Foot Rule definition in Appendix T - Glossary ) to energized lines or equipment:

Training in the potential electrical shock hazards associated withequipment operation under these conditions

Training in techniques for proper equipment grounding (OSHA regulation1910.269(p)(4)(iii)(c))

Refresher training is recommended every two years

4.11.4 Operating Zone for Mobile Equipment (OSHA regulation 1910.269(p)(4))

A potential for electrical shock hazard exists when mobile equipment is operated within the Ten (10)-Foot Rule area of energized, non-insulated, high-voltageconductors or to energized, exposed, high-voltage current-carrying equipment

parts (or to parts that have the potential for becoming energized). (NFPA 70E,130.5 (E))

To help eliminate this risk, follow the safety recommendations below.

Approach Distances (NFPA 70E, 130.5 (E)(1))

a) For lines and equipment energized at 50 kV or less, employees may not

bring materials or equipment closer than 10 (305 cm) to exposed live parts. For more than 50 kV, the distance is 10 plus 4 (10 cm) for every10 kV over 50 kV. (OSHA regulation 1910.333(c)(3)(iii))

b) Recommend that areas within a horizontal distance of 10of an overhead line be "coned off" with appropriate barricades

c) Whenever it is possible that any part of a vehicle or its load could violatethe Ten (10)-Foot Rule by error, malfunctions, inadvertent operation, or


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any other cause, ground the vehicle or barricade around it. (OSHAregulations 1910.269(p)(4)(iii) and (c)(4))

d) If it is difficult for the operator to accurately determine the distance between the equipment and the energized parts, assign another person toobserve the clearance and give timely warnings when the minimum

clearance distance is approached. (OSHA regulation 1910.269(p)(4)(ii))

e) It is generally recommended that no equipment or material be hoisted over energized, non-insulated high-voltage conductors or equipment. Anyexception to this policy should require approval by the location manager or his or her designee. Submit a documented plan for this type of work.

f) When operating in close proximity to energized conductors or circuit parts, inspect all mobile equipment in accordance with the section of this practice on inspection and testing of mechanized equipment (section 7.4 ).Properly ground or barricade this equipment in accordance with thesection on grounding mobile equipment (section 4.11.5 ). (OSHAregulation 1910.269(p)(4)(i); NFPA 70E, 130.5 (E); OSHA regulation1910.333(c)(3)(iii)(c))

g) Post minimum approach distances on a plate of durable non-conductivematerial so it is visible to the operator.

Mobile Equipment in Transit

The following clearances must be observed for equipment in transit with no load and the boom is lowered:

For voltages less than 50 kV, observe a minimum clearance of 4 (122

cm). For voltages higher than 50 kV, increase the clearance 4 (10 cm) for

every 10 kV over that voltage.

When visual conditions make it difficult for the operator to maintain thedesired clearance, designate a person to observe clearance for the operator.

EXCEPTION: An exception to this procedure is where lines have been de-energized and visibly grounded or where insulating barriers

have been erected to prevent physical contact. (NFPA 70E,130.5 (E)(1)); OSHA regulation 1910.333(c)(3)(iii)).

4.11.5 Grounding Mobile Equipment

Apply safety ground leads to mobile equipment as covered by this section.

Materials


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Ground leads should be not less than 2/0 flexible-stranded copper rubber-covered cable to provide physical strength. The cable jacket is for mechanical protection of the conductor only.

Ground leads should be visually inspected for any type of damage or wear beforeinstalling.

Methods

Only personnel trained in the proper grounding techniques should attach/detachgrounding sets.

Ground mobile equipment before raising a crane or derrick boom or similar equipment.

On a vehicle, trailer, or other mobile equipment (i.e., cranes, line trucks, and aeriallifts), make a connection from a suitable ground plate or stud on the vehicle to the

best ground available in the immediate work area.

On distribution circuits, the best ground available is normally the commonneutral or ground grid system. The second choice is a tower or other grounded structure. Only use a driven ground rod as a final alternative. Instruct workers tostay clear of the driven ground location. Use other protective means, such as

barricades, as necessary to avoid step potential and touch potential hazardsthat may occur around the driven rod during a ground fault.

Follow the correct grounding sequence: First, attach the ground lead to the best available ground. Then attach the ground lead to the vehicle.

Follow the correct sequence when removing grounds: Remove the ground device only after the crane, derrick boom, or similar

parts of the equipment have been removed from the vicinity of the potentially energized conductors or equipment

First, detach the ground lead from the vehicle. Then detach the ground lead from the ground.

4.11.6 Sample Procedures for Working Near Overhead Electrical Lines and Equipment

For procedures used by one business unit for working near overhead lines and equipment, see Appendix R .

4.12 Infrared Testing

(ASTM E1934-99a)

4.12.1 Safety Interlocks


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5.0 New Design, Modifications and Construction

5.1 Equipment Design Considerations

Many equipment design elements are covered in the companys Safety in Designs manual.

Design, operation, and maintenance considerations for personnel safety relevant to electricalsafety issues might include any combination of the following:

a) Separate low-energy circuits from circuits having a large arc flash hazard.

b) Apply current-limiting fuses, where appropriate, to reduce the arc flash hazard.

c) Purchase motor control centers with guards covering internal exposed live partsabove 120 volts.

d) Use ground-fault circuit interrupters to reduce shock hazards for portableequipment.

e) Include fast protection that will clear faults as quickly as possible and reduce thearc exposure time in the protective system design. Differential protection, with atotal fault clearing time of approximately 0.1 second, will greatly reduce arcexposure and the probability of escalation to a more severe fault involving two or more phases. Differential protection is recommended for all switchgear operatingat over 1000 volts.

f) Limit transformer sizes to 1,500 kVA and below to avoid excessive flash energyfor 480- and 600-volt systems.

g) Keep the arc flash hazard on 208Y/120 volt systems to a minimum risk level by

limiting the size of supply transformers at this voltage to less than 125 kVA.(IEEE Std. 1584-2002 9.3.2)

h) Specify remote closing and tripping capability, using either a plug-in cord and control or a supervisory control panel switch (for remote-operation), for all circuit

breakers operating at over 1,000 volts. This process allows the operator to beoutside of the flash protection boundary while closing or tripping a circuit breaker.

i) Specify two tie circuit breakers between switchgear buses to improve theelectrical isolation for busbar or switchgear maintenance. Workers could thenwork on or within a switchgear cubicle without the possibility of one set of circuit

breaker stabs being energized.

j) Specify closed-door and remotely operated racking (insertion and removal)capability for switchgear.

k) Specify insulated bus, which prevents or minimizes arc propagation within thegear after the fault initiates and can reduce the arc flash hazard, for all electricalswitchgear and control gear of all voltages.


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5.6 Perimeter Fence Grounding

(OSHA regulation 1910.269(u)(3); NESC sections 93E and 93C6)

To minimize the shock hazard associated with induced or impressed voltages on perimeter fences, comply with the following recommendations during modifications/construction:

Where high-voltage power lines cross over fences, ground the fence at the point of crossing and at a distance not to exceed 150 (45 m) on either side.

When fences run under or are parallel to high-voltage power lines, ground them atintervals not to exceed 150 (45 m).

In the conditions described in the two points above, bond any gate or other opening bya buried bonding strap.

When using armored high-voltage cables, the grounding practices described in this sectionneed not apply.

5.7 Pipelines, Conveyors and Metal Structures

Where these items are parallel to, or pass under, high-voltage power lines, follow proper grounding design.

5.8 Signage

Signs are essential for conveying information regarding a potential electrical shock hazard.They are also used to convey operation and/or maintenance information.

This section of the practice makes no attempt to describe all types of signs, all locationswhere signs may be required, or all possible lettering to be used. Use the references listed within this practice to obtain the necessary information for sign requirements at your location.

5.8.1 Design

Consider the following for signage requirements: Material Make signs out of a durable material that is appropriate for the

anticipated environmental conditions and expected length of exposure.

Colors and shapes Make the color and shape of the sign consistent withregulatory and consensus practices requirements.

Lettering Use large and highly visible lettering and anticipate dark or low-light situations.

International symbols Use internationally accepted symbols as much as practicable.

5.8.2 Location


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At a minimum, place signs of warning/information as follows:

a) On all doors, gates and fence locations for substations.

b) On doors to switchgear rooms and on other similar compartments where potentially energized exposed electrical parts are located.

c) On all transmission and/or distribution structures where employee or public presence may be expected.

d) In the case of multi-support structures, locate the signs on each supportingmember.

e) Where a low-voltage bus is supplied from two or more sources and presents a back-feed opportunity to the high-voltage system (and aninterlock system is not provided), conspicuously display a sign that warnsof this potential problem.

f) If temporary alterations must be made to secondary load supply systems inorder to maintain power supply continuity at the secondary voltage level(thus presenting a back-feed opportunity), then conspicuously display asign warning of this potential problem until the need for the temporaryalteration is abated.

g) At roadways or railways where horizontal or vertical clearance fromenergized or potentially energize

Documents

Electrical Safe Work Practice