arc flash fhm cover 10.11

8/11/2019 Arc Flash Fhm Cover 10.11

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FHM TRAINING TOOLS

This training presentation is part of FHMs

commitment to creating and keeping safe

workplaces.

Be sure to check out all the training programs

that are specific to your industry.


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These materials have been developed based on applicable federal laws and regulations in place at the time the materials were created. The program

is being provided for educational and informational purposes only and does not constitute and is not intended to provide OSHA compliance certification,

regulatory compliance, a substitute for any "hands on training required by applicable laws and regulations, or other legal or professional advice or

services. By accessing the materials, you assume all responsibility and risk arising from the use of the content contained therein.2010 Grainger Safety Services, Inc.

Arc Flash Safety


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Learning Objectives

After this course, you will:

Understand the Arc Flash Hazard

Recognize National Consensus

Standards on the topic

Be familiar with the

OSHA requirements


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Course Agenda

Presentation Agenda:

Introduction to Arc Flash

National Consensus Standards

The OSHA Position


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Introduction to

Arc Flash

Section


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Arch Flash

Arc flash or arc blast is:

The arc of high-amperage currents through the air.

A discharge of high voltages across a gap between

conductors

The current travels through the air

Temperatures as high as

35,000 Fahrenheit


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What causes an arc flash?

Bridging electrical contacts with a conducting object

Dropped tools

Buildup of conductive dust or corrosion

Causes


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Arc Flash Conditions

Arc flash conditions:

Working on an energized circuit

Electrical equipment failure


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Three primary hazards:

1. Thermal radiation and intense heat

2. Pressure wave blast

3. Molten metal

Arc Flash Hazards


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Thermal Radiation and Intense Heat

Factors affecting degree of injury:Skin color

Area of skin exposed

Type of clothing worn

To reduce risk of burn:

Proper clothing

Work distances

Over-current protection


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Pressure wave blast:

25,000-amp arc:

Feels like a force of about 480 pounds

May cause serious ear damage

May result in memory loss due to concussion

Pressure wave may throw victim:May propel objects over

great distances

Pressure Wave Blast


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Molten Metal

High-voltage arcs can melt electrical equipment:

Molten metal may be propelled great distances


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National

Consensus

Standards

Section 2


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National Consensus Standard:

Promulgated by a nationally recognized standards-

producing organization

Offers opportunity to consider diverse views

Designated by the Secretary

National Consensus Standards


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The OSH Act:

Only national consensus standards that have beenadopted as, or specifically incorporated byreference into, an OSHA standard provide a meansof compliance with the OSH Act

While requiring employers to comply with OSHAstandards, the OSH Act also authorizes OSHA totreat certain violations, which have no direct orimmediate relationship to safety andhealth, as de minimis, requiringno penalty or abatement

Compliance with National Consensus Standards


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Standard fo r Wo rkp lace Electr ic al Safety:

Wide range of electrical safety issues

Assist employers comply with OSHA standards

NFPA 70E


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Four Protective Strategies

Four protective strategies:

1. Creating an electrically

safe work condition

2. Training workers

3. Planning the task

4. Selecting and using personal

protective equipment


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Understanding terminology is essential to implement

control measures

Terminology


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Arc Flash Hazard Analysis:

Measures incident energy that may strike an

employee

Determines the arc flash protection boundary

Establishes the personal protective

equipment necessary

Helps create practices to accomplishthe desired work

Arc Flash Hazard Analysis


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The working distance:

Distance from where worker stands to flash location

Common distance is 18 inches

Incident energy can be used to

select protective equipment

Working Distance


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Incident Energy

Incident energy:

Measure of thermal energy at working distance from

an arc fault

Measured in Calories per square Centimeter,or cal/cm2

2nd degree burn of human

skin is at 1.2 cal/cm2


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The Arc Flash Protection Boundaryisthe distance from which a person could

receive a second degree burn

Arc Flash Protection Boundary


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How to Use NFPA 70E

NFPA 70E is valuable in complying with

the OSHA electrical standards


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The OSHA

Position

Section 3


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OSHA standards as they relate to NFPA 70E:

OSHA does not enforce requirements of NFPA 70E

NFPA 70E can be used by OSHA and employers as

guides in making hazard analyses and selectingcontrol measures

OSHA Use of National Consensus Standards


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Does OSHA issue General Duty Clause violations to

companies who do not follow the new NFPA 70E?

A violation of the General Duty Clause exists if an

employer fails to furnish a workplace that is free from

recognized hazards

The General Duty Clause is not used to enforce the

provisions of consensus standards

The General Duty Clause usually

is not used if there is astandard that applies to the

particular condition, practice,

means, operation, or

process involved

The General Duty Cause


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Marking of Electrical Equipment

OSHA has no specific requirement for marking of

electrical equipment to warn qualified persons of

potential arc flash hazards.

Paragraph (e) of 1910.303 requires employers to

mark electrical equipment with descriptivemarkings, including the equipment's voltage,

current, wattage, or other ratings as necessary


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Is flame-resistant clothing required for employees working on

electrical installations covered by Subpart S?

OSHA's present requirements in Subpart S, Safety-Related

Work Practices, are based on NFPA 70E-1983, which did not

at that time include specific provisions for

flame-resistant clothing More recent versions of NFPA 70E

have included such body

protection provisions

OSHA's existing Subpart S doesnot include a specific requirement

for fire-resistant clothing

Flame-Resistant Clothing


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OSHA pro vis ions for select ion and us e of

wo rk pract icescontained in 1910.333(a)(1)generally require de-energization of live parts

before an employee works on or near them.

Exposure is limited to when the equipment is

shut down and when the qualified employeeverifies, by use of a test instrument, a de-

energized state

When employees perform work on energized

circuits, as permitted by 1910.333(a)(1), tools

and handling equipment that might makecontact with exposed energized parts must be

insulated in accordance with 1910.335(a)(2)(i)

OSHA-Requires De-energization


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Personal protective Equipment (PPE):

Must be worn for eyes and face when there is

danger of injury

Use equipment to protect employees from:

Electric shocks

Blast

Arc flash burn hazards

Additional OSHA Requirements


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NFPA 70E-2004 standards:

Arc Flash Hazard analysis

Flash-protection boundary

Personal protective equipment

NFPA 70E, Article 130 provisions:

Energized electrical work

authorization permitBrief employees before they

start each job

Supplemental Steps to Ensure Worker Safety


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Additional Information

Additional Information:

29 CFR 1910 Subpart S, Electrical

National Fire Protection Agency:

NFPA 70E: Standard for Electrical Safetyin the Workplace 2009

OSHA 3075:

Controlling Electrical Hazards 2002

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