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EHS-268

Intro to NFPA 70E

Standard For Electrical Safety In The

Workplace

Keith Gershon, EHS Electrical Safety Engineer

Class Objectives

You will be able to:

Define the scope of your work, the hazardsand the controls, in terms of NFPA 70E in

.Specifically,

Recognize hazards of electricity

Describe the purpose of NFPA 70E and itsrelationship with OSHA and LBNL

Describe primary protection from hazards ofelectricity

Class Objectives

You will be able to: Apply safe work conditionrequirements

Evaluate shock and arc flash protectionboundaries

Describe correct selection and use of

electrical PPE

This class is NOT Qualified Workertraining

What is a Qualified Person? Look it up now

What this course is NOT

n

Qualified Person, Art 100 & 110.6(D)(1)

This class does not teach specific skills

or safety techniques to qualify you as anelectrical worker. You will demonstrate

these skills as part of your AHD.

Shock

Direct/Indirect

Electrocution

Hazards of Electricity

Burns

Arc Flash/Blast

Fire

Explosions

Hazards of Electricity Shock/Electrocution

Current Effect

1mA Barely perceptible

1- 5mA P erc ept io n th res ho ld

9-16mA = Let go threshold (hung up)

Invasive current exceeds the bodys

ability to control voluntary and

autonomic processes.

Break contact

16-30mA = Highly Dangerous

5-9mA Painful sensations ( involuntaryreactions)

9-16mA Muscular contraction (cant let go)

16-30mA Biological issues (internal heating)

30-100mA Respiratory paralysis

Ventricular fibrillation

Tissue burning

Cardiac and biological issues

Internal tissue heating

30-100mA = Fatal Exposure

Respiratory paralysis

Cardiac fibrillation

Internal burns

F acto rs:

Skin resistance

Path

Physiological diversity

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Hazards of Electricity Burns

Burns can result

when a personcontacts energizedparts resulting in

body parts.

Electrical burns ofthis type usuallyrequire specializedburn treatment andresult in loss ofbody parts.

Hazards of Electricity Arc Flash/Blast

Pressure Waves

Molten Metal35,000 F

Copper Vapor:Solid to VaporExpands by67,000 times

Intense Light

Hot Air-Rapid Expansion

Shrapnel

Sound Waves

NFPA 70E and OSHA

NFPA 70E and OSHAs Safety-RelatedWork Practices requirements are to

protect you from these hazards.

What is NFPA 70E?

First released in 1979 to address thoseelectrical safety requirements necessaryfor the practical safeguarding ofemployees in their pursuit of gainfulemployment.

Made up of three chapters; Chap 1,Safety-Related Work Practices, Chap 2,Safety-Related Maintenance, Chap 3,Safety for Special Equipment.

One constant focussafety ofemployees at work as relates to

exposure to electrical hazards.

Do We Have To Do It ?

Legal Status of NFPA 70E:Not adopted by OSHA

Not adopted by CalOSHA

Enforceable through OSHA

General Duty Clause

Part of 10CFR 851, therefore mandatoryfor LBNL

NFPA 70E and OSHA

NFPA 70E is a how to comply standard forOSHA electrical regulations.

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OSHA & NFPAHow Do They

Work Together:

It certainly seems to me that if

Im an employer, and I want to comply

with a general requirement forpro ec ng my empoyees rom e ec r cshock and electric arc, that the

first place Im going to look is

NFPA 70E.David Wallis

OSHA DirectorIEEE Interview

Whats in it ?

Chapter 1: SafetyRelated Work Practices

Chapter 2: Safety-Related MaintenanceRe uirements

Chapter 3: Safety Requirements For SpecialEquipment

This course focuses on Chapter One.

Whats in it ?

Most of what is unique to NFPA 70E is foundin Chapter 1: SafetyRelated Work Practices.Qualified versus Unqualified Persons

Training

Electrical Safety Program

Hazard Analyses for Shock and Flash

Lockout/Tagout

Energized Electrical Work Permits

Approach Boundaries and PPE.

Elect r ic a l ly Safe Work Cond i t ion

(130.1)

Most electrical work is required to be done in anElectrically Safe Work Condition

NO EXPOSURES!

Electrically Safe Work Condition = LOTO

Follow LBNL LOTO; 70E LOTO is not as

stringent

PPE is your last resort!

REMEMBER!

Deenergized work is your priority!

Ask yourself

Have I analyzedthis hazard?

LOTO is done to protect someone whois working on equipment from beingexposed to an unintended restart of the

WHY is LOTO done?

equ pmen or a azar rom an energysource.

The purpose of LOTO is to preventaccidents that are caused by energyrelease.

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EACH WORKER who is working on theequipment must have a lock on the equipment:

WHO MUST PERFORM LOTO?

Lock Key Protected Worker

You do not lock for anybody else;Nobody locks for you

1 + 1 = 1

Who Is Authorized To Perform Lockout/Tagout?

To perform LOTO you must:

1. Have received LOTO classroom training(EHS 256). Task and equipment specific,additional on-the-job training is required;and

2. Be specifically authorized by your divisionalline management (supervisor, etc.) toperform LOTO procedures.

These qualifications = Authorized Employee

Retraining will be required through course EHS 258 every two years

NFPA 70E provides 6 basic steps forestablishing:

Electrically Safe Work Condition What does this instrument indicate?

The presence of ACvoltage!

Can I use a proximity style tester for ZeroEnergy Verification under LOTO?

.person must usea multi-meter to

verify theabsence of

voltage.Cannot be accomplished with this device!

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Exception

High Voltage Equipment

A qualifiedperson may be approved touse grounding methods in combination

assure a deenergized condition on highvoltage equipment (see p.22)

These are the only times a worker maybe exposedto live parts

1. De-energizing introduces additional orincreased hazards

2. De-energizing is infeasibledue toequipment design or operationallimitations

1. De-energizing introduces additionalor increased hazards

For Example,

Life support equipment

Emergency alarm systems

Ventilation equipment for hazardous gases

2. De-energizing is infeasibledue toequipment design or operational

limitations

Dia nostics testin measurin

Work on a circuit that is part of a largecontinuous process that would need tobe completely shut down

infeasibleadj : not capable of being carried out or put into

practice

inconvenient

adj : not suited to your comfort, purpose or needs

inconvenientcannot serve tojustify work on or near exposed

live parts- NFPA 70E Handbook

What NOT to do

Analyze the work package

Figure out how to do it safely

Put on PPE Go to work

It is important to understand: We are not managingaccidentsWE ARE MANAGING EXPOSURES!

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Energized Work Permit

If the equipment is not placed in

an electrically safe workcondition, a written permit isrequired

Energized Work Permitforms are found in

Appendixes A and B of

Pub 3000

Testing/Troubleshooting/Inspecting does not require writtenpermit, IF it is covered in your AHD!

Energized Work Permit

Testing/Troubleshooting does

not require a permit, but acompleted and authorized AHDis required

Even if an energized work permit is notrequired, and you have a completed and

REMEMBER!

,practices (which may include work zones

and PPE) are stillrequired!

A Job Briefin Checklist

Job Briefing Checklist

is found in Appendix C

of Pub 3000

Quiz on 130.1If energized work is justified, the task must be

REMEMBER!

AHD

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130.2 Approach Boundaries to Live Partsfor work being done under a permit, or

testing / troubleshooting

Shock Protection Boundaries

Flash Protection Boundary

Outer boundaryfor shockprotection

SHOCK Approach Boundaries

Shock Boundaries

Unqualifiedpersons may notcross unescorted

Escort must be aqualified person

Restricted Approach Boundary

Appropriate PPErequired

Qualified persons

Shock Boundaries

have no additionalrestrictions.

Unqualified personsmay never crossRestricted ApproachBoundary

Prohibited Approach Boundary

How close can the qualified person work?

Qualified personsmay work up tothe ProhibitedApproach

Shock Boundaries

Boundary

Requires workplan, voltage-rated gloves,insulated toolsand possibly

more.

Prohibited Approach Boundary - SHOCK

Working within theprohibited approachboundary is the equivalent

of performing live-line

Shock Boundaries

work.

Requires written work planapproved by management.

What are your approach

Approach Boundaries for Shock Protection

Shock Boundaries

NFPA 70E, Table 130.2(C)

s ances

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PPE :

Shock Protection

Gloves come in various voltage classes, types,sizes and colors

Rubber insulating gloves must be used withleather protectors to prevent damage

Exception:

Gloves may be used without protectors if the

Leather Protectors

wor requ res unusua exter ty, an t e wor will not damage the glove.

If protectors are not used, derate glove by oneclass.

Derate 00 gloves are to 250V

Gloves that have been used withoutprotectors must remain derated, and shall not

be used with protectors until given aninspection and electrical retest.

Exercise II - Shock Boundaries

Hazards of Electricity Arc Flash/Blast

Pressure Waves

Molten Metal35,000 F

Copper Vapor:Solid to VaporExpands by67,000 times

Intense Light

Hot Air-Rapid Expansion

Shrapnel

Sound Waves

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The energy expelled during an arc-flash/blast is known as

incident energy.

The heat enerated b the

Hazards of Electricity Arc Flash/Blast

incident energy is measured incalories-per-square-centimeter(cal/cm2).

1.2 cal/cm2 is the on-set of a second-degree burn. Holdingyour finger in the flame of a lighter for 1 second is theequivalent of 1 cal/cm2.

Flash Protection BoundaryFlash Protection Boundary

The point at whichthe incident energydrops to 1.2 cal/cm2.

The Flash Protection Boundary may be LESS than the Shock ProtectionBoundary

Flash Protection BoundaryFlash Protection Boundary

or could be GREATER

Flash Protection Boundary

The Flash ProtectionBoundary and PPE Level are

determined by the calculationsof a Flash HazardAnal sis..

If your equipment does not havean arc flash hazard label, it is

acceptable to acquire theinformation on the closest

upstream panel, provided there isno transformer in between.

Flash Protection Boundary

If the Flash Protection Boundary is not calculated, itwill usuallybe 4

but do not ASSUME 4!

Work Zone

Established toindicate either

Limited Approach

Boundary orFlash ProtectionBoundary and

protectunqualifiedemployees

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Flash Hazard Analysis

Required when work is done inside the

Flash Boundary

Documented

FR Clothing and other PPE must beused to protect against the incident

energy

Alternative Method: Use table 130.7(C)(9) in 70E to determine the

Hazard/Risk Category based on the task. From the Hazard/Risk

Category the appropriate PPE shall be selected using 130.7(C)(10).

OSHA :29 CFR 1910.132(d) Personal Protective Equipment

(1)Hazard Assessment and PPE

NFPA 70E and OSHA

are present, or likely to be present, which necessitate PPE.

29 CFR 1910.335(a) Use of protective equipmentPersonal protective equipment

(i) Employees working in areas where there are potentialelectrical hazards shall be provided with, and shall use,electrical protective equipment that is appropriate for the specific

parts of the body..

PPE :

1.2 Cal 1.3-8 Cal 8.1-25 Cal 25.1-40 Cal

Hazard Risk

Category 1/2

Hazard Risk

Category 3

Hazard Risk

Category 0

Hazard Risk

Category 4

Insulated gloves/leathers

Hard hats

Personal Protective Equipment (PPE)

Face Shields/Flash Hoods

FR Clothing

Insulated tools

Dielectric shoes (optional)

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PROBLEM

WITH TABLES:

Example:208 Volt Panel4,200 Amps Arcing FaultClearing Time Over 2 SecondsTable Category: 1Calculated: Category 4

Example:480 Volt Motor Control Center16,000 Amps Arcing FaultClearing Time .01 SecondsTable Category: 2 w/ Double Layer HoodCalculated: Category 0

Both examples, when removing bolted covers.

LBNL Uses a Hybrid System

Calculations areperformed todetermine incident

Hazard / Risk categoryis matched to incidentenergy

Table 130.7(C)(10) isused to determine PPE

PPE is your last resort!

REMEMBER!

Deenergized work is your priority!

Ask yourself

Have I analyzedthis hazard?

Meters must be rated for thevoltage and location

Tools

Must be a ro riatel rated forvoltage and energy levels.

Undamaged.

Marking on ratedinsulated tool per ASTM 1505

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What single work practice will MOST protect you and

other employees from electrical shock and arc-flash/blast hazards?

Electrical Hazards - Summary

Establishing an electrically safe work condition.

When an electrically safe work condition cannot be

established, you must: Have an approved energized work permit, which includes a

Job Briefing.

Energized Electrical Work - Summary

Exceptions: Diagnostics/Troubleshooting, Voltagemeasurements, current measurements, similar tasks,

which require an AHD.

Establish a work zone.

Wear both shock and flash protection PPE.

Use insulated tools.

-Any questions?

THANK YOU!