Welcome
Arc Flash
Regulations & Requirements
Updated 12/07
Arc Flash
Regulations & Requirements
OR
How to work “live” without
making an ash of yourself *
* Credit to Regional OSHA Training Coordinator
What Is
is Arc Flash?
Arc flash is a short circuit through air that flashes
over from one exposed live conductor to another
conductor or to ground.
Lightning is an
example of a naturally
occurring arc flash.
Electric Arc Facts
 TYPICALLY LASTS LESS THAN A SECOND
 EXTREMELY HIGH RADIANT ENERGY
 EXPLOSIVE IN NATURE
CAN IGNITE AND/OR MELT
CONVENTIONAL WORK CLOTHING
Slide Courtesy of Oberon
< 740 mph
15000 °C
IR
165 db
Visible
UV
1000 °C
2000 psf
50 cal/cm2
ARCFlash
Arc
FLASH
Injuries
From Arc Flash:
 Severe burns from heat and molten metal
 Damage to eyesight
From Arc Blast:
 Loss of brain function due to concussion
 Hearing loss from ruptured eardrums
 Shrapnel wounds from flying metal parts
 Other injuries from force of explosion
ARC Common
How
FLASH Is It?
 Most hospital admissions due to electrical
accidents are from arc flash burns, not from
electrical shocks!
 Of the 350 workers killed by electricity in 2005,
50% were related to arc flash
 5 to 10 arc flash incidents occur in the USA each
day, resulting in an average estimated 1 death
every other day
ARC FLASH
What
Are The Costs?
DEATH …
 Or years of medical treatment,
 with costs from $1-5 million for
severe burns
 Victim may never return to work
 or enjoy same quality of life!
 OSHA fines, civil lawsuits
 Equipment damage, production loss
The First Rule About Working “Live”
Bottom Line
 DON’T! De-energize and Lockout/Tagout instead.
 80% of the electrical fatalities in this country occur
where the power could have been off.
 Reasons Given For Working Live:
 Not wanting to pay overtime
 Slows production down
 Takes too long - inconvenient
 “Safety has priority over service
continuity, equipment damage or economics”…
Institute of Electrical and Electronic Engineers ‘Buff Book’
OSHA 1910.333(a)(1) De-energized Parts
“Live parts to which an employee may be
exposed shall be de-energized before the
employee works on or near them, unless the
employer can demonstrate that de-energizing
introduces additional or increased hazards or
is infeasible due to equipment design or
operational limitations.”
ARC FLASH
What
Can Cause Arc Flash?
 Accidental contact or even just positioning a
conductive object too close to high-amp current
 Sparks (dropping tools, racking breakers, etc.)
 Equipment or circuit breaker failure
 Breaks or gaps in insulation
 Dust, corrosion, other impurities
 Fumes or chemical vapors
ARC FLASH
When
Are You Exposed?
 Installing conduits & bus duct switches
 Working on control circuits
 Cleaning starter buckets in a MCC
 Applying safety grounds
 Operating disconnect switches and breakers
 Taking a voltage reading
 Removing, installing circuit breakers or fuses
 Anytime you’re inside the Flash Protection Boundary
ARCFlash
Arc
FLASH
Regulations
 OSHA 29 CFR Subpart S, 1910.331 – 335
“Electrical Safety Related Work Practices”
 NFPA 70E-2004 “Standard For Electrical Safety In The
Workplace”
 To order call 800-344-3555 or go to www.nfpacatalog.org
 IEEE 1584 “Guide For Performing Arc Flash Hazard
Calculations”
 To order call 800-701-4333 or go to http://standards.ieee.org
 ANSI / NFPA 70-2005 National Electric Code
NFPA 70E
OSHA IS THE SHALL &
NFPA 70E IS THE HOW
 Industry consensus standards, notably NFPA 70E, can
be used by employers as guides to making the
assessments and equipment selections required by the
standard. Similarly, in OSHA enforcement actions,
they can be used as evidence of whether the employer
acted reasonably.
Regulatory Objectives
Objective of arc flash regulations is to limit
injury to curable 2nd degree burns.
Adhering to min. requirements does NOT:
 Eliminate risk of burn injury completely
 Protect workers from effects of arc blast
ARC FLASH
Incident
Energy
 Incident energy determined by:
Magnitude of fault current
Duration of arc fault
Distance from flash source
 Research shows that incident energy of approx.
1.2 cal/cm² will cause a 2nd degree burn.
ARC FLASH
Flash
Boundary
 Flash protection boundary should be set at point
where incident energy equals 1.2 cal/cm²
 When work on live exposed parts is in progress:
Unprotected workers must remain outside flash
protection boundary.
Workers inside boundary must wear proper
flash protection clothing.
ARC FLASH
Protective
Clothing
NFPA 70E defines five levels of arc flash hazards:
Category 0 (low risk) through Category 4 (high risk)
Protective apparel requirements shown in table 130.7(C)(10) of NFPA70E-2004
Cat.
Arc Rating
Clothing Description
0
NA
Non-melting, flammable materials (ie., untreated cotton, wool, rayon, or silk,or
blends of these materials) with a fabric weight at least 4.5 oz / yd² [1 layer]
1
4 cal / cm²
FR shirt and FR pants or FR coverall [1 layer]
2
8 cal / cm²
Cotton underwear (conventional short sleeve and brief/shorts), plus FR shirt
and FR pants [2 layers]
3
25 cal / cm²
Cotton underwear plus FR shirt and FR pants plus FR coverall, or cotton
underwear plus two FR coveralls. [3 layers]
4
40 cal / cm²
Cotton underwear plus FR shirt and FR pants plus multilayer flash suit [3 or
more layers]
ARC FLASH
Personal
Protective Equipment Requirements
Protective equipment requirements are covered in Table
130.7(C)(10) of NFPA70-2004
Category 0
Hard hat
Category 2
Category 4
X
X
FR hard hat liner
Safety glasses or goggles
Arc-rated face shield
X
X
X
X
X
Flash suit hood
X
Hearing protection
X
X
Leather gloves
X
X
Leather shoes
X
X
ARC FLASH
Flammable
Clothing
Before arc flash
During arc flash
After arc flash
Untreated cotton shirt (5.7 oz/yard²)
ARC FLASH
Flame
Resistant Clothing
Before arc flash
During arc flash
After arc flash
DuPont NOMEX® IIIA Shirt (4.5 oz/yd²)
ARC FLASHThe Flash Hazard Category
Determining
The flash hazard category can be determined in
either of two ways:
 Use table 130.7(C)(9)(a) Hazard / Risk
Category Classification in NFPA 70E-2004
Perform flash hazard analysis as described in
130.3 of NFPA 70E-2004
ARC FLASH
Labeling
Requirements
Article 110.16 of the ANSI / NFPA 70-2005
National Electric Code states:
“Switchboards, panelboards, industrial control panels, meter socket
enclosures, and motor control centers that are in other than dwelling
occupancies and are likely to be subject to examination, adjustment,
servicing or maintenance while energized must be field marked to warn
qualified personnel of potential arc flash hazards. The marking shall be
located so as to be clearly visible to qualified persons before examination,
adjustment, servicing or maintenance of equipment.”
NEC2008 Adds: - Electrical equipment such as……
- Multiple occupancy dwellings not exempt
ARC vs.
New
FLASH
Existing Installations
 Labeling is responsibility of owners, not
equipment manufacturers or suppliers.
 Applies to all new installations and as well as any
existing installations that are added, altered or
modified in any way.
 Many companies taking safe (and efficient)
approach of labeling all existing installations.
ARC FLASH
Generic
Labels
 Current regulation says only that label must warn of arc
flash hazards.
3.5” x 5”
2” x 4”
Bilingual (En/Sp) labels also available
ARC FLASH
Write-On
Labels
 Many employers including additional info such as
hazard category and required arc flash PPE
 Others also providing shock hazard information
ARC FLASH
Pre-Printed
Labels
Labels with preprinted hazcat and PPE mean less
writing, less chance of someone making a mistake
ARC FLASH
Custom
Printed Labels
 Send data in spreadsheet and have Brady print for you
 Print using Brady industrial label printing systems
ARC FLASH
Facility
ID Label Printers
MarkWare™ Software
+
GlobalMark® printer
or
MiniMark™ printer
ARC FLASH
Power
Management Software
Print arc flash labels to Brady industrial labeling printers
direct from 3-party power management programs such as:
SKM
ETAP
ESA EasyPower
ARC FLASH
Electrical
Work Permits
 Required by NFPA 70E
when working live
 Allows relevant hazards
and safe work practices to
be specified on a job by
job basis
 Ensures proper mgmt
control of high-risk work
activities
ARC FLASH
Training
Tools
Promote awareness of the dangers associated with arc flash accidents
And make sure your employees know how to protect themselves!
ARC FLASH
Protect
Yourself!
 Lockout before service and maintenance
 Follow approved safe work procedures
 Wear proper protective apparel and equipment
 Use insulated gloves, tools, blankets and barriers
 Keep equipment free of dirt and corrosion
 Operate equipment at the rated voltage
 Be careful to avoid generating sparks
ARCSafe
Stay
FLASH
– Brady Can Help!
Other areas where Brady can help:
 Lockout / Tagout
 Hazardous chemicals / Right-to-Know
 Slips & Trips
 Process & equipment identification
 5S and Lean Manufacturing
 Production tracking and product labeling