Training Presentation - Arc Flash Safety.ppt

flash training

1. Arc Flash SafetyArc Flash Safety

2. Arcing Fault EventsArcing Fault Events
An arc is produced by flow of electrical An arc is produced by flow of electrical
current through ionized air after an initial current through ionized air after an initial
flashover or short circuit.flashover or short circuit.
Arcs produce some of the highest Arcs produce some of the highest
temperatures known to occur on earth – temperatures known to occur on earth –
up to 35,000 degrees F. This is four times up to 35,000 degrees F. This is four times
the surface temperature of the sun.the surface temperature of the sun.
All known materials are vaporized at this All known materials are vaporized at this
temperature.temperature.

3. Arc Flash EffectsArc Flash Effects
Average of 1,710 (reported) electrical Average of 1,710 (reported) electrical
burns per year in USAburns per year in USA
–Burn from intense heatBurn from intense heat
–Trauma from blast pressureTrauma from blast pressure
–Toxic gases from vaporized metalToxic gases from vaporized metal
–Sprayed molten metal dropletsSprayed molten metal droplets
–Hearing damage from sound pressure waveHearing damage from sound pressure wave
–Eye damageEye damage

9. Electrical Safety RequirementsElectrical Safety Requirements
OSHA 1910.333 (a)(1) & NFPA 70E 130.1OSHA 1910.333 (a)(1) & NFPA 70E 130.1
Qualified electrical workers shall not be asked Qualified electrical workers shall not be asked
to work on equipment that is “hot” or “live” to work on equipment that is “hot” or “live”
except for two reasons:except for two reasons:
1.1.De-energizing introduces additional or De-energizing introduces additional or
increased hazardsincreased hazards
Such as cutting ventilation to a hazardous locationSuch as cutting ventilation to a hazardous location
2.2.Infeasible due to equipment design or Infeasible due to equipment design or
operational limitationsoperational limitations
Such as doing voltage testing for diagnosticsSuch as doing voltage testing for diagnostics

10. Elements of Arc Flash SafetyElements of Arc Flash Safety
Defined responsibilitiesDefined responsibilities
Calculation of degree of arc flash hazardCalculation of degree of arc flash hazard
Personal protective equipmentPersonal protective equipment
TrainingTraining
Tools for safe workTools for safe work
Warning labels on equipmentWarning labels on equipment

11. ResponsibilitiesResponsibilities
YSU will provide:YSU will provide:
–PPEPPE
–TrainingTraining
–LabelingLabeling
–Insulated toolsInsulated tools
–Lock out/tag out Lock out/tag out
devicesdevices
YSU employee will:YSU employee will:
–Follow safe work Follow safe work
practicespractices
–Use appropriate Use appropriate
insulated toolsinsulated tools
–Wear PPE when Wear PPE when
requiredrequired

12. Arc Flash Hazard AnalysisArc Flash Hazard Analysis
Determines flash protection boundary and Determines flash protection boundary and
PPE requirements as a function of location PPE requirements as a function of location
and work activity.and work activity.
Arc flash hazard and flash protection Arc flash hazard and flash protection
boundary varies with:boundary varies with:
–Type of equipment and configurationType of equipment and configuration
–Available short circuit currentAvailable short circuit current
–VoltageVoltage
–Predicted fault duration – protective devices Predicted fault duration – protective devices
upstream on the arcing fault and their settingsupstream on the arcing fault and their settings

13. Flash Protection BoundaryFlash Protection Boundary
Linear distance from exposed live parts Linear distance from exposed live parts
within which a person could receive within which a person could receive
second degree burns resulting from an arc second degree burns resulting from an arc
flash.flash.

14. Flash Protection BoundariesFlash Protection Boundaries
Limited Approach BoundaryLimited Approach Boundary
–Entered only by qualified persons or unqualified Entered only by qualified persons or unqualified
persons escorted by qualified personpersons escorted by qualified person
Restricted Approach BoundaryRestricted Approach Boundary
–Entered only by qualified persons required to use Entered only by qualified persons required to use
shock protection techniques and equipmentshock protection techniques and equipment
Prohibited Approach BoundaryProhibited Approach Boundary
–Entered only by qualified persons requiring same Entered only by qualified persons requiring same
protection as if in direct contact with live partsprotection as if in direct contact with live parts

15. Prohibited shock boundary:Qualified persons only - PPE as if direct
contact with live part
Restricted shock boundary:Qualified persons only
Limited shock boundary: Qualified or unqualified persons*
*only if accompanied by qualified person
Note: shock boundaries dependent on system voltage level
Flash Protection Boundary (FPB)
Must wear appropriate PPE
FPB dependent on fault level and
time duration.
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16. Approach BoundariesApproach Boundaries
Each boundary is a Each boundary is a
sphere to be sphere to be
observed in all observed in all
directions three directions three
dimensionally.dimensionally.

17. LabelingLabeling
Switchboards, panel boards, industrial Switchboards, panel boards, industrial
controls, etc. that require examination, controls, etc. that require examination,
adjustment, or maintenance while adjustment, or maintenance while
energized shall be labeled.energized shall be labeled.

18. LabelingLabeling
Labels shall be designed to warn of Labels shall be designed to warn of
potential arc flash hazardspotential arc flash hazards
YSU will classify arc flash hazard labels YSU will classify arc flash hazard labels
into two types:into two types:
–Low voltage below 680 voltsLow voltage below 680 volts
–High voltage above 680 voltsHigh voltage above 680 volts

19. Insulated ToolsInsulated Tools
Flame retardantFlame retardant
Double insulated. A first hi-visibility yellow Double insulated. A first hi-visibility yellow
layer provides the insulation for the tool, and layer provides the insulation for the tool, and
the outer hi-visibility orange layer protects the the outer hi-visibility orange layer protects the
lower yellow layer. lower yellow layer.
NOTE: If the yellow layer can NOTE: If the yellow layer can
be seen through the orange be seen through the orange
layer, the tool should be layer, the tool should be
removed from service.removed from service.

20. NFPA 70E 120.1NFPA 70E 120.1
120.1 Process of Achieving an 120.1 Process of Achieving an
Electrically Safe Work ConditionElectrically Safe Work Condition
–An electrically safe work condition shall be An electrically safe work condition shall be
achieved when performed in accordance achieved when performed in accordance
with the procedures of 120.2 and verified by with the procedures of 120.2 and verified by
the following process:the following process:

21. Electrically Safe Work ConditionElectrically Safe Work Condition
1.1.Determine all electrical sources using up-to-Determine all electrical sources using up-to-
date information, drawings, diagrams, etc.date information, drawings, diagrams, etc.
2.2.After properly interrupting the load current, After properly interrupting the load current,
open the disconnecting device(s) for each open the disconnecting device(s) for each
source.source.
–At this point, the equipment or circuit is simply At this point, the equipment or circuit is simply
de-energized, not in an electrically safe work de-energized, not in an electrically safe work
condition.condition.

22. Electrically Safe Work ConditionElectrically Safe Work Condition
3.3.Visually verify that disconnecting Visually verify that disconnecting
means fully open if possiblemeans fully open if possible
4.4.Apply lockout tagout devicesApply lockout tagout devices
5.5.Test for absence of voltageTest for absence of voltage
Verify proper operation of test Verify proper operation of test
equipmentequipment
6.6.Ground phase conductors if there Ground phase conductors if there
is a possibility of induced is a possibility of induced
voltages or stored energyvoltages or stored energy

23. Electrically Safe Work ConditionElectrically Safe Work Condition
Until these six steps have been executed, Until these six steps have been executed,
some exposure to an electrical hazard still some exposure to an electrical hazard still
exists and proper PPE is required.exists and proper PPE is required.

24. Safe Work PracticesSafe Work Practices
For open box work where the circuit can For open box work where the circuit can
not be de-energized, safe work practices not be de-energized, safe work practices
will include:will include:
–Use of insulated toolsUse of insulated tools
–Use of personal protective equipmentUse of personal protective equipment
–Not working aloneNot working alone

25. Safe Work PracticesSafe Work Practices
If the box is open and the circuit can not If the box is open and the circuit can not
be de-energized personal protective be de-energized personal protective
equipment is required; for 120 volts:equipment is required; for 120 volts:
–Safety glassesSafety glasses
–Cotton shirt and pantsCotton shirt and pants
*Note: NFPA recommends cotton under *Note: NFPA recommends cotton under
garments for use when an arc flash hazard is garments for use when an arc flash hazard is
present.present.

26. Safe Work PracticesSafe Work Practices
If the box is open and the circuit can not If the box is open and the circuit can not
be de-energized, personal protective be de-energized, personal protective
equipment is required; for 120-680 volts:equipment is required; for 120-680 volts:
–Safety glasses, ear plugsSafety glasses, ear plugs
–Cotton shirt and Indura pants Cotton shirt and Indura pants
(MSU work uniform)(MSU work uniform)
–Category 2 face shieldCategory 2 face shield
–Category 2 Indura coatCategory 2 Indura coat
–Low voltage insulated glovesLow voltage insulated gloves

27. Safe Work PracticesSafe Work Practices
If the box is open and the circuit If the box is open and the circuit
can not be de-energized, personal can not be de-energized, personal
protective equipment is required, protective equipment is required,
for high voltage of 680V or higher:for high voltage of 680V or higher:
–Safety glasses, ear plugsSafety glasses, ear plugs
–Cotton shirt and Indura pantsCotton shirt and Indura pants
–Category 4 hoodCategory 4 hood
–Category 4 Indura coat and pantsCategory 4 Indura coat and pants
–High voltage insulated gloves with High voltage insulated gloves with
leather over glovesleather over gloves

28. PPE – NFPA 70E Table 130.7PPE – NFPA 70E Table 130.7
Typical Protective Clothing Systems
Hazard/Risk
Category
Clothing Description
(Typical number of clothing layers is given in parentheses)
Required Minimum
Arc Rating of PPE
[(J/cm
2
(cal/cm
2
)]
0 Non-melting, flammable materials (i.e., untreated cotton,
wool, rayon, or silk, or blends of these materials) with a
fabric weight at least 4.5 oz/yd
2
(1)
N/A
1 FR Shirt and FR pants or FR coverall (1) 16.74 (4)
2 Cotton underwear - conventional short sleeve and
brief/shorts, plus FR shirt and FR pants (1 or 2)
33.47 (8)
3 Cotton underwear plus FR shirt and FR pants plus FR
coverall, or cotton underwear plus two FR coveralls (2 or 3)
104.6 (25)
4 Cotton underwear plus FR shirt and FR pants plus multi-
layer flash suit (3, or more)
167.36 (40)

29. SummarySummary
Equipment should be placed in an electrically Equipment should be placed in an electrically
safe work condition prior to servicing the safe work condition prior to servicing the
equipment.equipment.
Safe work practices should be followed to Safe work practices should be followed to
reduce the hazards associated with an arc reduce the hazards associated with an arc
flash.flash.
If necessary to work on live parts:If necessary to work on live parts:
–120 volts - safety glasses & cotton uniform120 volts - safety glasses & cotton uniform
–120-680 volts – Category 2 arc flash suit120-680 volts – Category 2 arc flash suit
–680 volts and above – Category 4 arc flash suit680 volts and above – Category 4 arc flash suit