Upload
abhijitwce
View
226
Download
0
Embed Size (px)
Citation preview
8/11/2019 Arc Flash Fhm Cover 10.11
1/32
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.
8/11/2019 Arc Flash Fhm Cover 10.11
2/32
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
8/11/2019 Arc Flash Fhm Cover 10.11
3/32
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
8/11/2019 Arc Flash Fhm Cover 10.11
4/32
Course Agenda
Presentation Agenda:
Introduction to Arc Flash
National Consensus Standards
The OSHA Position
8/11/2019 Arc Flash Fhm Cover 10.11
5/32
Introduction to
Arc Flash
Section
8/11/2019 Arc Flash Fhm Cover 10.11
6/32
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
8/11/2019 Arc Flash Fhm Cover 10.11
7/32
What causes an arc flash?
Bridging electrical contacts with a conducting object
Dropped tools
Buildup of conductive dust or corrosion
Causes
8/11/2019 Arc Flash Fhm Cover 10.11
8/32
Arc Flash Conditions
Arc flash conditions:
Working on an energized circuit
Electrical equipment failure
8/11/2019 Arc Flash Fhm Cover 10.11
9/32
Three primary hazards:
1. Thermal radiation and intense heat
2. Pressure wave blast
3. Molten metal
Arc Flash Hazards
8/11/2019 Arc Flash Fhm Cover 10.11
10/32
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
8/11/2019 Arc Flash Fhm Cover 10.11
11/32
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
8/11/2019 Arc Flash Fhm Cover 10.11
12/32
Molten Metal
High-voltage arcs can melt electrical equipment:
Molten metal may be propelled great distances
8/11/2019 Arc Flash Fhm Cover 10.11
13/32
National
Consensus
Standards
Section 2
8/11/2019 Arc Flash Fhm Cover 10.11
14/32
National Consensus Standard:
Promulgated by a nationally recognized standards-
producing organization
Offers opportunity to consider diverse views
Designated by the Secretary
National Consensus Standards
8/11/2019 Arc Flash Fhm Cover 10.11
15/32
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
8/11/2019 Arc Flash Fhm Cover 10.11
16/32
Standard fo r Wo rkp lace Electr ic al Safety:
Wide range of electrical safety issues
Assist employers comply with OSHA standards
NFPA 70E
8/11/2019 Arc Flash Fhm Cover 10.11
17/32
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
8/11/2019 Arc Flash Fhm Cover 10.11
18/32
Understanding terminology is essential to implement
control measures
Terminology
8/11/2019 Arc Flash Fhm Cover 10.11
19/32
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
8/11/2019 Arc Flash Fhm Cover 10.11
20/32
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
8/11/2019 Arc Flash Fhm Cover 10.11
21/32
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
8/11/2019 Arc Flash Fhm Cover 10.11
22/32
The Arc Flash Protection Boundaryisthe distance from which a person could
receive a second degree burn
Arc Flash Protection Boundary
8/11/2019 Arc Flash Fhm Cover 10.11
23/32
How to Use NFPA 70E
NFPA 70E is valuable in complying with
the OSHA electrical standards
8/11/2019 Arc Flash Fhm Cover 10.11
24/32
The OSHA
Position
Section 3
8/11/2019 Arc Flash Fhm Cover 10.11
25/32
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
8/11/2019 Arc Flash Fhm Cover 10.11
26/32
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
8/11/2019 Arc Flash Fhm Cover 10.11
27/32
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
8/11/2019 Arc Flash Fhm Cover 10.11
28/32
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
8/11/2019 Arc Flash Fhm Cover 10.11
29/32
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
8/11/2019 Arc Flash Fhm Cover 10.11
30/32
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
8/11/2019 Arc Flash Fhm Cover 10.11
31/32
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
8/11/2019 Arc Flash Fhm Cover 10.11
32/32
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