70e Electrical Safety Training

Topics

• Electrical hazards/injuries

• OSHA 1910 Subpart S

• NFPA 70E requirements

• “Qualified” Worker”?

• Electrical Safe Work Practices

• Understanding arc flash hazard categories & PPE

• Understanding approach boundaries

• Implementing 70E and qualifying employees

Why it’s important…

• 1,213 electrical related workplace

fatalities from 2003 to 2007*

• 13,150 severe injuries*

*Electrical Safety Foundation International 2008 Survey

Injuries from Electric Shock• Electrocution

• Electrical burns

• Nerve, muscle, tissue damage

• Internal bleeding

• Secondary injuries

– Falls

Muscle, nerve, and tissue destruction

Thermal burnsBurnsSecondary injuries

Cardiac arrest andrespiratory failure

Electrical Injuries

© Business & Legal Reports, Inc. 0912

Electric Shock• Received when current passes

through the body

• Severity of the shock depends on:

– Path of current through the body

– Amount of current flowing through the body

– Length of time the body is in the circuit

• LOW VOLTAGE DOES NOT MEAN LOW HAZARD Exit

Ground

Entrance

Electrical Safety Standards

OSHA Standards 29 CFR 1910

OSHA Standards

• 1910 Subpart S – Electrical

– 1910.301 – .308 = Safe installation

– 1910.309 – .330 = Reserved

– 1910.331 – .335 = Work practices

– 1910.336 – .398 = Reserved

– 1910.399 – Definitions

– Appendix A – Reference Documents

1910.331 - Scope

• Applies to qualifed and unqualified employees

performing work on:

– Premises wiring

– Connecting to supply

– Other wiring

– Optical fiber cable

• Does NOT apply to generation, distribution, or

communication (specific standards for these)

• Refers to 1910.399 for definition of qualified

persons.

“Qualified Person” – OSHA 1910.399

• One who has received training in and has

demonstrated skills and knowledge in the

construction and operation of electrical

equipment and installation and the hazards

involved.

1910.332 Training

• Employees who face a risk of electric shock

that is not reduced to a safe level installation

requirements must be trained.

• Occupations in Table S-4 must be trained.

• Other employees if they face a risk of shock.

Table S-4• Blue collar supervisors

• Electrical and electronic engineers

• Electrical and electronic equipment assemblers

• Electrical and electronic technicians

• Electricians

• Industrial machine operators

• Material handling equipment operators

• Mechanics and repairers

• Painters

• Riggers and roustabouts

• Stationary engineers

• Welders

• Footnote(1) Workers in these groups do not need to be trained if their work or the work of those they supervise does not bring them or the employees they supervise close enough to exposed parts of electric circuits operating at 50 volts or more to ground for a hazard to exist.

1910.332 Training

• Training focused on:

– Recognizing live parts

– Determining voltage of live parts

– Clearance distances specified in 1910.333

1910.333 Selection and Use of Work

Practices• Focused on work near exposed energized or

potentially energized parts.

– Locking and tagging

– Deenergization

– Verifying deenergized condition

– Reenergizing

– Overhead power lines (clearance distances)

– Illumination

– Several other tasks

1910.333 Selection and Use of Work

Practices

• "Deenergized parts." Live parts to which an employee may be exposed shall be deenergizedbefore the employee works on or near them, unless the employer can demonstrate that deenergizing introduces additional or increased hazards or is infeasible due to equipment design or operational limitations. Live parts that operate at less than 50 volts to ground need not be deenergized if there will be no increased exposure to electrical burns or to explosion due to electric arcs.

1910.334 Use of Equipment

• Covers things like:

– Portable equipment

– Plugs and cords

– Reclosing circuits

– Inspection of equipment

1910.335 Safeguard for Personnel

Protection

• Personal Protective Equipment

– Must use when exposed

– Maintenance

– Inspection

• Insulated hand tools

• Guarding of exposed parts during work

NFPA 70E

Electrical Hazards

• NFPA 70E – A dangerous condition such

that contact or equipment failure can result

in:

– Electric Shock

– Arc flash burn

– Thermal burn

– Arc blast

Arc Flash & Arc Blast

• Arc Flash – electrical

short circuit that occurs

when air flashes from an

exposed live conductor, to

either another conductor

or to ground.

• Arc Blast – pressure wave

caused by the arc flash.

Arc Flash/Blast

• Concentrated energy explodes outward

• High intensity flash

• Temperatures can reach 35,000

• Pressure wave can reach 200lbs/sq. inch

• Vaporize conductors and copper and explode particles like buckshot.

Arc Flash Effects

• Severe burns

• Broken bones

• Vision damage

• Hearing loss

• Brain/internal injuries

• Punctures and lacerations

• Death

Causes of Arc Flash

• Improper training

• Improper work procedures

• Dropped tools

• Accidental contact with electrical

systems

• Installation failure

• Inadequate SCCR

• Voltage testing with inappropriate

equipment

Causes of Arc Flash (cont.)

• Buildup of dust, corrosion

on insulating surfaces

• Improper maintenance

• Sparks produced during

racking of breakers,

replacement of fuses and

closing into faulty lines.

• Inattentiveness/Overconfi

dence

“Qualified Person” – NFPA 70

• One who has the skill and knowledge related to

the construction and operation of the electrical

equipment and installations and has received

safety training to recognize and avoid the hazards

involved.

– May be considered qualified with respect to certain

equipment & method but still unqualified for others.

Qualified Persons

Training Requirements• Understand specific electrical hazards

• Knowledgeable of the construction and operation of the equipment

• Identify & understand the relationship between electrical hazards and possibly injury

• Distinguish exposed live parts

• Able to determine voltage of live parts

• Understands and complies with arc flash and shock hazard boundaries.

Qualified Persons

Training (cont.)– Proper use of precautionary

techniques

– PPE, including arc-flash &

shock protection

– Insulated tools

– Demonstrate how to select and

use a voltage meter

– Decision-making process used

to determine the degree and

extent of the hazard

Justification for WorkNFPA 70E 130.1

• Energized electrical conductors and circuit parts to which an employee might be exposed shall be put into an electrically safe work condition before an employee works within the Limited Approach Boundary of those conductors or parts.

• Unless – the employer can demonstrate that de-energizing introduces additional hazards or is infeasible.

– Interruption of life support systems

– Deactivation of emergency alarm systems

– Shutdown of hazardous location ventilation systems

– Circuits and conductors that operate at less than 50 volts

Justification for WorkNFPA 70E 130.1 (cont.)

• Other work that may be performed within

the limited approach boundary of exposed

energized electrical conductors or circuits:

– Testing

– Troubleshooting

– Voltage measuring

Safe Work Practices

– De-energize-Lockout Policy

– Don’t wear conductive apparel

– Work area must be illuminated

– Never reach into blind spots

– Don’t allow conductive liquids near electrical work or equipment

– Buddy system (over 1,000 volts, work in pairs)

– Do not defeat electrical interlocks

– Use nonconductive ladders

Steps to NFPA 70E Compliance

1. Have an arc hazard survey completed.

2. Implement any recommendations to reduce the

hazards.

3. Develop and implement a labeling system.

4. Determine what tasks will be performed and at

what hazard category.

5. Train (qualify) employees and provide PPE.

Arc Hazard Survey

• Conducted by an engineering firm

• Survey includes:

– Single line diagram of electrical system

– Incident energy levels

– Current limiting device coordination

– Calculates a hazard risk category and approach boundaries

– Develops recommendations to reduce high hazard risk categories

Reduce the hazards!

• Some examples:

– Change fuses

– Develop a maintenance program

– Adjust circuit breakers

– Install additional disconnects

Arc Flash Label

Arc Flash Label

Arc Ratings

*NFPA 70E Table

130.7(C)(11)

Hazard/Risk

Category

Incident Energy

(cal/cm2)

0 0 - 1.2

1 1.2 - 4

2 4 - 8

3 8 - 25

4 25 - 40

Dangerous Over 40

NFPA 70E Approach Boundaries

NFPA 70E Approach Boundaries

(cont.)• The qualified

worker is responsible for ensuring physical barriers are in place and all approach boundaries are enforced during work.

! WARNING

Arc Flash and Shock Hazard

Appropriate PPE Required

34 inch Flash Hazard Boundary

3.46 cal/cm^2 Flash Hazard at 18 inches

Class 1

VR Gloves-Tools, Proper Clothes, Safety Glasses,

Hardhat

480 VAC Shock Hazard when cover is removed

42 inch Limited Approach

12 inch Restricted Approach

1 inch Prohibited Approach

Bus Name: PP-MCC-G81, Prot Device: PP-PDP-G71-6

ProhibitedRestrictedLimited

Flash Boundary – 4 ft. or calculated

Warning label

provides

boundary

information

Specific Tasks

• Troubleshooting only! NO “WORK!”

– Checking / replacing fuses

– Checking motor starters

– Checking amp draw

– Checking relays

Train….Train….Train….Train

• 3-step process….

– Controls 101

– Arc Flash Hazard Training

– Equipment Specific Training

• Hands on!

Arc Flash Hazard Training

• Labeling system

• Glove selection and testing

– Shock protection

• Arc flash rated clothing

– Arc flash protection

Glove Labeling ChartChoose the right glove by voltage rating

Voltage-rated Gloves• First line of defense

• Choose the right size

• Leather protectors must be worn over the rubber gloves

• Gloves must be tested

– Before first issue and every 6 months

– If tested, but not issued for service, glove may not be put into service unless tested within previous 12 months.

• Checked before use

– Roll-up test

– Inflator test

Arc-Rated FR Clothing & PPE

• Layering– Outer layers must be flame resistant

– Under layers must be non-melting

• Fit – Clothing shall fit properly (loose), w/ least interference

• Coverage – Clothing must cover potentially exposed areas (wrist, neck)

• Care & Maintenance– Inspect before use

– Launder according to mfg’s instructions

PPE - Hazard Risk Category 00-1.2 cal/cm2

• 100% cotton long sleeve shirt

• Long pants

• Safety glasses

• Hearing protection

• Leather and insulated gloves (as required)

• Leather work boots

PPE - Hazard Risk Category 11.2 - 4 cal/cm2

• 4+ cal long sleeve shirt & long pants (or) coveralls

• Hardhat

• Safety glasses

• Arc rated faceshield

• Hearing protection (inserts)

• VR gloves

• Leather gloves

• Leather work boots

PPE - Hazard Risk Category 24 - 8 cal/cm2

• 8+ cal long sleeve shirt & long pants (or) coveralls

• Hardhat

• Safety glasses

• Arc rated faceshield

• Hearing protection (inserts)

• VR gloves

• Leather gloves

• Leather work boots

PPE - Hazard Risk Category 38 - 25 cal/cm2

• 25+ flashsuit w/ hood over long sleeve shirt and long pants

• Safety glasses

• Arc rated faceshield

• Hearing protection (inserts)

• VR gloves

• Leather gloves

• Leather work boots

PPE - Hazard Risk Category 425 - 40 cal/cm2

• 40+ flashsuit w/ hood over FR

long sleeve shirt and long

pants

• Safety glasses

• Arc rated faceshield

• Hearing protection (inserts)

• VR gloves

• Leather gloves

• Leather work boots

Hands-On Training

• How to use a multi-meter

• Set up a safe scenario

– Lockout upstream before class!

• Trainee performs

• Unacceptable performance = NOT qualified!

Qualification

• All steps completed

– Survey

– Calculations

– PPE determination

– Training

• Employees qualified

Questions

Acknowledgement

I ___________________________________, have completed the 70e Electrical Safety Training.

(Print Name)

Date: ________________

Please print the acknowledgement sheet, fill in requested information and deliver to Facilities administrative office.