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OSHAGeneral Duty Clause.Section 5(a)(1)Each Employer shall
furnish to each ofhis employees employment and a place ofemployment
which are free fromecognized hazards that are causing or
are likely to cause death or seriousphysical harm to him or
her.
1910.335(b)(1)Safety-related work practices shall beemployed to
prevent electric shock orother injuries resulting from eitherdirect
or indirect electrical contacts,when work is performed near or
onequipment or circuits which are or maybe energized. The specific
safety-
elated work practices shall beconsistent with the nature and
extentof the associated electrical hazards.
1910.335(a)(1)(i) Personnel ProtectiveEquipmentEmployees working
in areas where thereare potential elect rical hazards shallbe
provided with, and shall use,electrical protective equipment thats
appropriate for the specific parts
of the body to be protected and for thework to be performed.
NFPA 70E 130.3 Arc Flash Hazard AnalysisAn arc flash hazard
analysis shalldetermine the Arc Flash protectionBoundary and the
personal protectiveequipment that people within the ArcFlash
Protection Boundary shall use.The arc flash hazard analysis shall
beupdated when a major modification orrenovation takes place. It
shall bereviewed periodically, not to exceedfive years, to account
for changes inthe electrical distribution system thatcould affect
the results of the arcflash hazard analysis. The arc flashhazard
analysis shall take intoconsideration the design of theovercurrent
protection device and its
opening time, including its conditionof maintenance.
110.6 Training Requirements(A) Safety Training.The training
requirements contained inthis section shall apply to employeeswho
face a risk of electrical hazardthat is not reduced to a safe level
bythe applicable electrical installationrequirements. Such
employees shall betrained to understand the specifichazards
associated with electricalenergy. They shall be trained
insafety-related work practices andprocedural requirements as
necessary toprovide protection from the electricalhazards
associated with theirrespective job or assignments.Employees shall
be trained to identifyand understand the relationship
betweenelectrical hazards and possibly injury.
Article 130.7 Personal and OtherProtective Equipment.130.7(C)(1)
General. When an employeeis working within the flash
protectionboundary he/she shall wear protectiveclothing and other
personal protectiveequipment in accordance with 130.3. Allparts or
the body inside the Arc FlashProtection Boundary shall be
protected.(This section uses the Flash HazardAnalysis to determine
the proper PPE)
NEC110.16 Flash Protection.Electrical Equipment such
asswitchboards, panelboards, industrialcontrol panels, meter
socketenclosures, and motor control centers,hat are in other than
dwelling
occupancies, and are likely to requireexamination, adjustment,
servicing, ormaintenance while energized shall beield marked to
warn qualified persons
of potential electric arc flashhazards. The marking shall be
locatedso as to be clearly visible toqualified persons before
examination,adjustment, servicing, or maintenanceof equipment.
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arc rating -the value attributed to materials that describes
their performance toexposure to an electrical arc discharge. the
arc rating is expressed in cal/cm^2and is derived from the
determined value (atpv) or energy of breakopen threshold(E bt
)(should a material system exhibit a breakopen response below the
atpv value)derived from the determined value of atpv or e bt .
arc flash protection boundary -when an arc flash hazard exists,
an approachlimit at a distance from a prospective arc source within
which a person couldreceive a second degree burn if an electrical
arc flash were to occur.
incident energy -the amount of energy impressed on a surface, a
certain distancefrom the source, generated suring an electrical arc
event. one of the units usedto measure incident energy is calories
per centimeter squared (cal/cm^2).
qualified person -one who has the skills and knowledge related
to theconstruction and operation of the electrical equipment and
installations and hasreceived safety training to recognize and
avoid the hazards involved.
shock hazard -a dangerous condition associated with the possible
release ofelectrical energy caused by contact or approach to
energized electrical equipment.
working distance -the dimension between the possible arc point
and the head andbody of the worker positioned in place to perform
assigned task.
hazard risk category table
important definitions
hrc cal/cm^2 required ppe
0 0-1.2untreated cotton long-sleeve shirt & long pant,
safetyglasses, hearing protection, voltate-rated electricalgloves
w/Leather protector.
1 1.2-4.0
fr (meet or exceed calculated incident energy) ls shirt
&pants (or coverall), balaclava, hardhat + arc rated faceshield
w/ wraparound guard (or flash suit hood), safetyglasses, hearing
protection, voltage-rated electricalgloves w/leather protectors,
heavy-duty leather work shoes.
2 4.0-8.0
fr (meet or exceed calculated incident energy) ls shirt
&pants (or coverall), balaclava, hardhat + arc rated faceshield
w/ wraparound guard (or flash suit hood), safetyglasses, hearing
protection, voltage-rated electricalgloves w/leather protectors,
heavy-duty leather work shoes.
3 8.0-25.0
fr (meet or exceed calculated incident energy) ls shirt
&pants (or coverall) w/af suit and hood so system meets
minrequired rating, hardhat + hard hat liner or balaclava,safety
glasses, hearing protection, voltage-ratedelectrical gloves with
leather protectors, heavy-dutyleather work shoes.
4 25.0-40.0
fr (meet or exceed calculated incident energy) ls shirt
&pants (or coverall) w/af suit and hood so system meets
minrequired rating, hardhat + hard hat liner or balaclava,safety
glasses, hearing protection, voltage-ratedelectrical gloves with
leather protectors, heavy-dutyleather work shoes.
Danger above 40.0 no adequate ppe to protect against all hazards
at thiscalculated incident energy level.
