Transcript 70e-electrical-safety

Implementing NFPA
70E Electrical Safety
Standards
St Louis, MO
May 26, 2010
Topics
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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……
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1,213 electrical related
workplace fatalities from 2003
to 2007*
13,150 severe injuries*
*Electrical Safety Foundation International 2008 Survey
Injuries
Injuries Electrical
from Electric
Shock
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Electrocution
Electrical burns
Muscle,
Cardiac
Secondary
nerve,
arrest and
Thermal
Burns
burns
Nerve, muscle,
tissue
tissue
respiratory
injuries
destruction
failure
damage
Internal bleeding
Secondary injuries
 Falls
© Business & Legal Reports, Inc. 0912
Electric Shock
Entrance
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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
Ground
Exit
Electrical Safety Standards
OSHA Standards 29 CFR 1910
OSHA Standards
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1910 Subpart S – Electrical
– .308 = Safe installation
 1910.309 – .330 = Reserved
 1910.301
1910.331
– .335 = Work practices
– .398 = Reserved
 1910.399 – Definitions
 Appendix A – Reference Documents
 1910.336
1910.331 - Scope
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Applies to qualifed and unqualified employees
performing work on:
 Premises
wiring
 Connecting to supply
 Other wiring
 Optical fiber cable
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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
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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.
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Table S-4
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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
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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
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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
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"Deenergized parts." Live parts to which an
employee may be exposed shall be deenergized
before 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
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Covers things like:
 Portable
equipment
 Plugs and cords
 Reclosing circuits
 Inspection of equipment
1910.335 Safeguard for Personnel
Protection
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Personal Protective Equipment
 Must
use when exposed
 Maintenance
 Inspection
Insulated hand tools
 Guarding of exposed parts during work
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NFPA 70E
Electrical Hazards
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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
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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
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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
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Severe burns
Broken bones
Vision damage
Hearing loss
Brain/internal injuries
Punctures and
lacerations
Death
Causes of Arc Flash
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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.)
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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
We’re in Missouri, so show me!
Racking a Breaker
Breaker Box Demonstration
“Qualified Person” – NFPA 70
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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
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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 Work
NFPA 70E 130.1
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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 deenergizing introduces additional hazards or is infeasible.
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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 Work
NFPA 70E 130.1 (cont.)
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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
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Have an arc hazard survey completed.
Implement any recommendations to reduce
the hazards.
Develop and implement a labeling system.
Determine what tasks will be performed
and at what hazard category.
Train (qualify) employees and provide PPE.
Arc Hazard Survey
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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!
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Some examples:
 Change
fuses
 Develop a maintenance program
 Adjust circuit breakers
 Install additional disconnects
Arc Flash Label
Arc Flash Label
Arc Ratings
Hazard/Risk
Category
*
0
Incident Energy
(cal/cm2)
0 - 1.2
1
1.2 - 4
2
4-8
3
8 - 25
4
25 - 40
Dangerous
Over 40
NFPA 70E Table 130.7(C)(11)
NFPA 70E Approach Boundaries
NFPA 70E Approach Boundaries
(cont.)
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The qualified
worker is
responsible
for ensuring
physical
barriers are
in place and
all approach
boundaries
are enforced
during work.
!
WARNING
Arc Flash and S hock Hazard
Appropriate P P E Required
34 inch
Flash Hazard Boundary
3.46
cal/cm^2 Flash Hazard at 18 inches
Class 1
480 VAC
42 inch
VR Gloves-Tools, Proper Clothes, Safety Glasses,
Hardhat
Shock Hazard when cover is removed
Limited Approach
12 inch
Restricted Approach
1 inch
Prohibited Approach
Bus Name: PP-MCC-G81, Prot Device: PP-PDP-G71-6
Warning label
provides
boundary
information
Flash Boundary – 4 ft. or calculated
Limited
Restricted
Prohibited
Specific Tasks
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Troubleshooting only! NO “WORK!”
 Checking
/ replacing fuses
 Checking motor starters
 Checking amp draw
 Checking relays
Train….Train….Train….Train
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3-step process….
 Controls
101
 Arc Flash Hazard Training
 Equipment Specific Training
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Hands on!
Arc Flash Hazard Training
Labeling system
 Glove selection and testing
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 Shock
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protection
Arc flash rated clothing
 Arc
flash protection
Glove Labeling Chart
Choose the right glove by voltage rating
Voltage-rated Gloves
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First line of defense
Choose the right size
Leather protectors must be worn over the rubber gloves
Gloves must be tested
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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
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Roll-up test
Inflator test
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Salisbury
video
Arc-Rated FR Clothing & PPE
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Layering
 Outer layers must be flame resistant
 Under layers must be non-melting
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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
*Photo courtesy of Salisbury
PPE - Hazard Risk Category 0
0-1.2 cal/cm2
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100% cotton long
sleeve shirt
Long pants
Safety glasses
Hearing protection
Leather and insulated
gloves (as required)
Leather work boots
PPE - Hazard Risk Category 1
1.2 - 4 cal/cm2
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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 2
4 - 8 cal/cm2
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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 3
8 - 25 cal/cm2
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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 4
25 - 40 cal/cm2
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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
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 Lockout
upstream before class!
Trainee performs
 Unacceptable performance = NOT qualified!
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Qualification
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All steps completed
 Survey
 Calculations
 PPE
determination
 Training
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Employees qualified