ARC Flash Safety

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FHM TRAINING TOOLS

This training presentation is part of FHM’s commitment to creating and keeping safe workplaces.

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Arc Flash Safety

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.

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

Course Agenda

Presentation Agenda:

► Introduction to Arc Flash

► National Consensus Standards

► The OSHA Position

Section 1

Introduction to

Arc Flash

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

Causes

What causes an arc flash?

► Bridging electrical contacts with a conducting object

► Dropped tools

► Buildup of conductive dust or corrosion

Arc Flash Conditions

Arc flash conditions:

► Working on an energized circuit

► Electrical equipment failure

Arc Flash Hazards

Three primary hazards:

1.

Thermal radiation and intense heat

2.

Pressure wave blast

3.

Molten metal

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

Pressure Wave Blast

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

Molten Metal

High-voltage arcs can melt electrical equipment:

► Molten metal may be propelled great distances

Section 2

National

Consensus

Standards

National Consensus Standards

National Consensus Standard:

► Promulgated by a nationally recognized standardsproducing organization

► Offers opportunity to consider diverse views

► Designated by the Secretary

Compliance with National Consensus Standards

The OSH Act:

► Only national consensus standards that have been adopted as, or specifically incorporated by reference into, an OSHA standard provide a means of compliance with the OSH Act

► While requiring employers to comply with OSHA standards, the OSH Act also authorizes OSHA to treat certain violations, which have no direct or immediate relationship to safety and health, as de minimis , requiring no penalty or abatement

NFPA 70E

Standard for Workplace Electrical Safety:

► Wide range of electrical safety issues

► Assist employers comply with OSHA standards

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

Terminology

Understanding terminology is essential to implement control measures

Arc Flash Hazard Analysis

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 accomplish the desired work

Working Distance

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

Incident Energy

Incident energy:

► Measure of thermal energy at working distance from an arc fault

► Measured in Calories per square Centimeter, or cal/cm 2

► 2nd degree burn of human skin is at 1.2 cal/cm 2

Arc Flash Protection Boundary

The Arc Flash Protection Boundary is the distance from which a person could receive a second degree burn

How to Use NFPA 70E

NFPA 70E is valuable in complying with the OSHA electrical standards

Section 3

The OSHA

Position

OSHA Use of National Consensus Standards

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 selecting control measures

The General Duty Cause

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 a standard that applies to the particular condition, practice, means, operation, or process involved

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 descriptive markings, including the equipment's voltage, current, wattage, or other ratings as necessary

Flame-Resistant Clothing

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 does not include a specific requirement for fire-resistant clothing

OSHA-Requires De-energization

OSHA provisions for selection and use of

work practices contained 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 employee verifies, by use of a test instrument, a deenergized state

► When employees perform work on energized circuits, as permitted by 1910.333(a)(1), tools and handling equipment that might make contact with exposed energized parts must be insulated in accordance with 1910.335(a)(2)(i)

Additional OSHA Requirements

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

Supplemental Steps to Ensure Worker Safety

NFPA 70E-2004 standards:

► Arc Flash Hazard analysis

► Flash-protection boundary

► Personal protective equipment

NFPA 70E, Article 130 provisions:

► Energized electrical work authorization permit

► Brief employees before they start each job

Additional Information

Additional Information:

29 CFR 1910 Subpart S, Electrical

National Fire Protection Agency:

NFPA 70E: Standard for Electrical Safety in the Workplace

®

2009

OSHA 3075:

Controlling Electrical Hazards 2002

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