Electrical Safety in the Electrical Safety in the WorkplaceWorkplace
FN000385/CRFN000385/CR
FN000385/CR, Electrical Safety in the WorkplaceFN000385/CR, Electrical Safety in the Workplace 22
OverviewOverview
NFPA 70E ObjectivesNFPA 70E Objectives
Electrical HazardsElectrical Hazards
Mitigation of HazardsMitigation of Hazards
Electrical Work ActivitiesElectrical Work Activities– Diagnostic vs. ManipulativeDiagnostic vs. Manipulative
FN000385/CR, Electrical Safety in the WorkplaceFN000385/CR, Electrical Safety in the Workplace 33
OverviewOverview
Fermilab Electrical Safety PolicyFermilab Electrical Safety Policy
Electrical Hazard AnalysisElectrical Hazard Analysis– Shock Hazard AnalysisShock Hazard Analysis– Arc Flash Hazard AnalysisArc Flash Hazard Analysis
Establishing an Electrically Safe Work Establishing an Electrically Safe Work ConditionCondition
Additional ResourcesAdditional Resources
FN000385/CR, Electrical Safety in the WorkplaceFN000385/CR, Electrical Safety in the Workplace 44
NFPA 70E ObjectivesNFPA 70E Objectives
Protect workers from electrical shock and Protect workers from electrical shock and arc-flash hazardsarc-flash hazards
Understand the work and associated Understand the work and associated electrical hazardselectrical hazards
Understand the PPE requirements for Understand the PPE requirements for electrical shock protection and electrical shock protection and arc-flash protectionarc-flash protection
FN000385/CR, Electrical Safety in the WorkplaceFN000385/CR, Electrical Safety in the Workplace 55
Electrical HazardsElectrical Hazards
Three Main HazardsThree Main Hazards
– Electric ShockElectric Shock
– Arc-FlashArc-Flash
– Arc BlastArc Blast
FN000385/CR, Electrical Safety in the WorkplaceFN000385/CR, Electrical Safety in the Workplace 6666
Electrical HazardsElectrical Hazards
Electric ShockElectric Shock– Electric current passes through the bodyElectric current passes through the body– 1 milliamp can feel the current1 milliamp can feel the current– 15 milliamps can’t let go of electrical source15 milliamps can’t let go of electrical source– 100 milliamps through chest can result in 100 milliamps through chest can result in
ventricular fibrillation which is usually fatalventricular fibrillation which is usually fatal– Automatic External Defibrillator (AED) Automatic External Defibrillator (AED)
only practical way to return heart to normal only practical way to return heart to normal rhythmrhythm
– Deep tissue burnsDeep tissue burns
FN000385/CR, Electrical Safety in the WorkplaceFN000385/CR, Electrical Safety in the Workplace
FN000385/CR, Electrical Safety in the WorkplaceFN000385/CR, Electrical Safety in the Workplace 77
Electrical HazardsElectrical Hazards
Arc FlashArc Flash– Electric current passes through air, Electric current passes through air,
between a “Hot” conductor and ground, between a “Hot” conductor and ground, or between “Hot” conductorsor between “Hot” conductors
– Severity is determined bySeverity is determined byAvailable fault currentAvailable fault currentConductor sizeConductor sizeTime or durationTime or duration
– Temperatures can reach 35,000 Degrees FTemperatures can reach 35,000 Degrees Froughly three times the surface temperature of roughly three times the surface temperature of the sunthe sun
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Electrical HazardsElectrical Hazards
Arc FlashArc Flash– Clothing or PPE that burns and melts to the Clothing or PPE that burns and melts to the
body is the most serious concernbody is the most serious concern– 203 Degrees F for 0.1 seconds results in third 203 Degrees F for 0.1 seconds results in third
degree burndegree burn– The incident energy threshold for the onset of a The incident energy threshold for the onset of a
second degree burn is 1.2 cal/cmsecond degree burn is 1.2 cal/cm22..– Exposure can easily cause skin burns and Exposure can easily cause skin burns and
ignite clothingignite clothing
FN000385/CR, Electrical Safety in the WorkplaceFN000385/CR, Electrical Safety in the Workplace 99
Electrical HazardsElectrical Hazards
Arc BlastArc Blast– Rapid expansion of air caused by an electrical Rapid expansion of air caused by an electrical
arcarcCaused by two sourcesCaused by two sources– Metal boiling and vaporizingMetal boiling and vaporizing– Heating of air from the arcHeating of air from the arc
Copper expands by a factor of 67,000 times when Copper expands by a factor of 67,000 times when vaporizedvaporizedBest categorized as an explosionBest categorized as an explosion– Hearing loss due to blast explosionHearing loss due to blast explosion– Lacerations/Punctures from blast debrisLacerations/Punctures from blast debris– Trauma from percussion forceTrauma from percussion force
FN000385/CR, Electrical Safety in the WorkplaceFN000385/CR, Electrical Safety in the Workplace 1010
Electrical HazardsElectrical Hazards
1997 F0 Compressor Room 480 volt MCC Arc Flash Event1997 F0 Compressor Room 480 volt MCC Arc Flash Event
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Mitigation of HazardsMitigation of Hazards
Arc BlastArc Blast– Work De-Energized Work De-Energized – Engineer Out the Hazard Engineer Out the Hazard – Follow Safe Work Practices Follow Safe Work Practices
Electrical Hazard AnalysisElectrical Hazard Analysis
Employ Lockout/Tagout of Hazardous Electrical Employ Lockout/Tagout of Hazardous Electrical Energy SourcesEnergy Sources
Use Voltage Insulating PPE and EquipmentUse Voltage Insulating PPE and Equipment
Use PPE for Arc-Flash ProtectionUse PPE for Arc-Flash Protection
Use Ground Fault Circuit InterruptersUse Ground Fault Circuit Interrupters
FN000385/CR, Electrical Safety in the WorkplaceFN000385/CR, Electrical Safety in the Workplace 1212
Diagnostic vs. Manipulative WorkDiagnostic vs. Manipulative Work
DiagnosticDiagnostic– Inspection, testing, voltage and/or current Inspection, testing, voltage and/or current
measurements, phase alignment, measurements, phase alignment, troubleshooting, circuit and signal tracing, troubleshooting, circuit and signal tracing, thermal imaging, etc. that are performed on or thermal imaging, etc. that are performed on or near exposed live parts within the Limited near exposed live parts within the Limited Approach BoundaryApproach Boundary
– Verification Associated with LOTO Verification Associated with LOTO – Performed by Performed by Qualified PersonsQualified Persons utilizing utilizing
appropriately rated measurement equipment appropriately rated measurement equipment and required PPE.and required PPE.
FN000385/CR, Electrical Safety in the WorkplaceFN000385/CR, Electrical Safety in the Workplace 1313
Diagnostic vs. Manipulative WorkDiagnostic vs. Manipulative Work
ManipulativeManipulative– Making, tightening or breaking of energized Making, tightening or breaking of energized
electrical connections or the replacement, electrical connections or the replacement, removal, or addition of electrical or mechanical removal, or addition of electrical or mechanical componentscomponents
– Examples include: Examples include: Replacing a duplex outlet, light switch, fluorescent Replacing a duplex outlet, light switch, fluorescent fixture ballast, fuses, circuit breakersfixture ballast, fuses, circuit breakers
Drilling or punching holes in a live panelboardDrilling or punching holes in a live panelboard
Pulling conductors into a live panelboardPulling conductors into a live panelboard
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Fermilab PolicyFermilab Policy
Do NotDo Not work on energized electrical work on energized electrical equipment unless absolutely necessary.equipment unless absolutely necessary.Diagnostic Energized Work is allowed only Diagnostic Energized Work is allowed only when the diagnostic activity is not feasible when the diagnostic activity is not feasible with the circuit de-energized.with the circuit de-energized.Manipulative Energized Work is prohibited Manipulative Energized Work is prohibited at Fermilab unless it can be demonstrated at Fermilab unless it can be demonstrated that de-energization introduces additional or that de-energization introduces additional or increased hazards or is infeasible due to increased hazards or is infeasible due to equipment design or operational limitationsequipment design or operational limitations
FN000385/CR, Electrical Safety in the WorkplaceFN000385/CR, Electrical Safety in the Workplace 1515
Fermilab PolicyFermilab Policy
Infeasible does not include InconvenientInfeasible does not include Inconvenient
Directorate Approval Required for Directorate Approval Required for Manipulative Energized WorkManipulative Energized Work
Fermilab policies and NFPA 70E apply to Fermilab policies and NFPA 70E apply to both the AC Power Distribution system and both the AC Power Distribution system and to Utilization Equipmentto Utilization Equipment
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Electrical Hazard AnalysisElectrical Hazard Analysis
Shock Hazard AnalysisShock Hazard Analysis
Arc-Flash Hazard AnalysisArc-Flash Hazard Analysis
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Shock Hazard AnalysisShock Hazard Analysis
Shock Hazard AnalysisShock Hazard Analysis– Limited Approach BoundaryLimited Approach Boundary
Distance from an exposed live part within which a Distance from an exposed live part within which a shock hazard existsshock hazard existsOnly Qualified persons and escorted unqualified Only Qualified persons and escorted unqualified persons are allowed within the Limited Approach persons are allowed within the Limited Approach Boundary.Boundary.
– Restricted Approach BoundaryRestricted Approach BoundaryDistance from an exposed live part within which there Distance from an exposed live part within which there is an increased risk of shock due to electrical arc-over is an increased risk of shock due to electrical arc-over that may result from inadvertent movement of that may result from inadvertent movement of personnel working in close proximity to the live part .personnel working in close proximity to the live part .
FN000385/CR, Electrical Safety in the WorkplaceFN000385/CR, Electrical Safety in the Workplace 1818
Shock Hazard AnalysisShock Hazard Analysis
Shock Hazard AnalysisShock Hazard Analysis– Prohibited Approach BoundaryProhibited Approach Boundary
Distance from an exposed live part within which work Distance from an exposed live part within which work is considered the same as making contact with the is considered the same as making contact with the live part.live part.
FN000385/CR, Electrical Safety in the WorkplaceFN000385/CR, Electrical Safety in the Workplace 1919
Shock Hazard AnalysisShock Hazard Analysis
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Shock Protection BoundariesShock Protection BoundariesTable 130.2(C) Approach Boundaries to Live Parts for Shock Protection. (All dimensionsare distance from live part to employee.)
Restricted Approach
Nominal System --------------------------------------------------- Boundary; Includes
Voltage Range, Phase to Phase
Exposed Movable Conductor
Exposed Fixed Circuit Part
Inadvertent Movement Adder
Prohibited Approach Boundary
Less than 50 Not specified Not specified Not specified Not specified
50 to 300 10 ft 0 in. 3 ft 6 in. Avoid contact Avoid contact
301 to 750 10 ft 0 in. 3 ft 6 in. 1 ft 0 in. 0 ft 1 in.
751 to 15 kV 10 ft 0 in. 5 ft 0 in. 2 ft 2 in. 0 ft 7 in.
15.1 kV to 36 kV 10 ft 0 in. 6 ft 0 in. 2 ft 7 in. 0ft 10 in.
36.1 kV to 46 kV 10 ft 0 in. 8 ft 0 in. 2 ft 9 in. 1 ft 5 in.
46.1 kV to 72.5 kV 10 ft 0 in. 8 ft 0 in. 3 ft 2 in. 2 ft 1 in.
72.6 kV to 121 kV 10 ft 8 in. 8 ft 0 in. 3 ft 3 in. 2 ft 8 in.
138 kV to 145 kV 11 ft 0 in. 10 ft 0 in. 3 ft 7 in. 3 ft 1 in.
161 kV to 169 kV 11 ft 8 in. 11 ft 8 in. 4 ft 0 in. 3 ft 6 in.
230 kV to 242 kV 13 ft 0 in. 13 ft 0 in. 5 ft 3 in. 4 ft 9 in.345 kV to 362 kV 15 ft 4 in. 15 ft 4 in. 8 ft 6 in. 8 ft 0 in.
500 kV to 550 kV 19 ft 0 in. 19 ft 0 in. 11 ft 3 in. 10 ft 9 in.
765 kV to 800 kV 23 ft 9 in. 23 ft 9 in. 14 ft 11 in. 14 ft 5 in.
Note: For Flash Protection Boundary, see 130.3(A).See definition in Article 100 and text in 130.2(D)(2) and Annex C for elaboration.
Limited Approach Boundary
Table 130.2(C) Approach Boundaries to Live Parts for Shock Protection. (All dimensionsare distance from live part to employee.)
Restricted Approach
Nominal System --------------------------------------------------- Boundary; Includes
Voltage Range, Phase to Phase
Exposed Movable Conductor
Exposed Fixed Circuit Part
Inadvertent Movement Adder
Prohibited Approach Boundary
Less than 50 Not specified Not specified Not specified Not specified
50 to 300 10 ft 0 in. 3 ft 6 in. Avoid contact Avoid contact
301 to 750 10 ft 0 in. 3 ft 6 in. 1 ft 0 in. 0 ft 1 in.
751 to 15 kV 10 ft 0 in. 5 ft 0 in. 2 ft 2 in. 0 ft 7 in.
15.1 kV to 36 kV 10 ft 0 in. 6 ft 0 in. 2 ft 7 in. 0ft 10 in.
36.1 kV to 46 kV 10 ft 0 in. 8 ft 0 in. 2 ft 9 in. 1 ft 5 in.
46.1 kV to 72.5 kV 10 ft 0 in. 8 ft 0 in. 3 ft 2 in. 2 ft 1 in.
72.6 kV to 121 kV 10 ft 8 in. 8 ft 0 in. 3 ft 3 in. 2 ft 8 in.
138 kV to 145 kV 11 ft 0 in. 10 ft 0 in. 3 ft 7 in. 3 ft 1 in.
161 kV to 169 kV 11 ft 8 in. 11 ft 8 in. 4 ft 0 in. 3 ft 6 in.
230 kV to 242 kV 13 ft 0 in. 13 ft 0 in. 5 ft 3 in. 4 ft 9 in.345 kV to 362 kV 15 ft 4 in. 15 ft 4 in. 8 ft 6 in. 8 ft 0 in.
500 kV to 550 kV 19 ft 0 in. 19 ft 0 in. 11 ft 3 in. 10 ft 9 in.
765 kV to 800 kV 23 ft 9 in. 23 ft 9 in. 14 ft 11 in. 14 ft 5 in.
Note: For Flash Protection Boundary, see 130.3(A).See definition in Article 100 and text in 130.2(D)(2) and Annex C for elaboration.
Limited Approach Boundary
Table 130.2(C) Approach Boundaries to Live Parts for Shock Protection. (All dimensionsare distance from live part to employee.)
Restricted Approach
Nominal System --------------------------------------------------- Boundary; Includes
Voltage Range, Phase to Phase
Exposed Movable Conductor
Exposed Fixed Circuit Part
Inadvertent Movement Adder
Prohibited Approach Boundary
Less than 50 Not specified Not specified Not specified Not specified
50 to 300 10 ft 0 in. 3 ft 6 in. Avoid contact Avoid contact
301 to 750 10 ft 0 in. 3 ft 6 in. 1 ft 0 in. 0 ft 1 in.
751 to 15 kV 10 ft 0 in. 5 ft 0 in. 2 ft 2 in. 0 ft 7 in.
15.1 kV to 36 kV 10 ft 0 in. 6 ft 0 in. 2 ft 7 in. 0ft 10 in.
36.1 kV to 46 kV 10 ft 0 in. 8 ft 0 in. 2 ft 9 in. 1 ft 5 in.
46.1 kV to 72.5 kV 10 ft 0 in. 8 ft 0 in. 3 ft 2 in. 2 ft 1 in.
72.6 kV to 121 kV 10 ft 8 in. 8 ft 0 in. 3 ft 3 in. 2 ft 8 in.
138 kV to 145 kV 11 ft 0 in. 10 ft 0 in. 3 ft 7 in. 3 ft 1 in.
161 kV to 169 kV 11 ft 8 in. 11 ft 8 in. 4 ft 0 in. 3 ft 6 in.
230 kV to 242 kV 13 ft 0 in. 13 ft 0 in. 5 ft 3 in. 4 ft 9 in.345 kV to 362 kV 15 ft 4 in. 15 ft 4 in. 8 ft 6 in. 8 ft 0 in.
500 kV to 550 kV 19 ft 0 in. 19 ft 0 in. 11 ft 3 in. 10 ft 9 in.
765 kV to 800 kV 23 ft 9 in. 23 ft 9 in. 14 ft 11 in. 14 ft 5 in.
Note: For Flash Protection Boundary, see 130.3(A).See definition in Article 100 and text in 130.2(D)(2) and Annex C for elaboration.
Limited Approach Boundary
Table 130.2(C) Approach Boundaries to Live Parts for Shock Protection. (All dimensionsare distance from live part to employee.)
Restricted Approach
Nominal System --------------------------------------------------- Boundary; Includes
Voltage Range, Phase to Phase
Exposed Movable Conductor
Exposed Fixed Circuit Part
Inadvertent Movement Adder
Prohibited Approach Boundary
Less than 50 Not specified Not specified Not specified Not specified
50 to 300 10 ft 0 in. 3 ft 6 in. Avoid contact Avoid contact
301 to 750 10 ft 0 in. 3 ft 6 in. 1 ft 0 in. 0 ft 1 in.
751 to 15 kV 10 ft 0 in. 5 ft 0 in. 2 ft 2 in. 0 ft 7 in.
15.1 kV to 36 kV 10 ft 0 in. 6 ft 0 in. 2 ft 7 in. 0ft 10 in.
36.1 kV to 46 kV 10 ft 0 in. 8 ft 0 in. 2 ft 9 in. 1 ft 5 in.
46.1 kV to 72.5 kV 10 ft 0 in. 8 ft 0 in. 3 ft 2 in. 2 ft 1 in.
72.6 kV to 121 kV 10 ft 8 in. 8 ft 0 in. 3 ft 3 in. 2 ft 8 in.
138 kV to 145 kV 11 ft 0 in. 10 ft 0 in. 3 ft 7 in. 3 ft 1 in.
161 kV to 169 kV 11 ft 8 in. 11 ft 8 in. 4 ft 0 in. 3 ft 6 in.
230 kV to 242 kV 13 ft 0 in. 13 ft 0 in. 5 ft 3 in. 4 ft 9 in.345 kV to 362 kV 15 ft 4 in. 15 ft 4 in. 8 ft 6 in. 8 ft 0 in.
500 kV to 550 kV 19 ft 0 in. 19 ft 0 in. 11 ft 3 in. 10 ft 9 in.
765 kV to 800 kV 23 ft 9 in. 23 ft 9 in. 14 ft 11 in. 14 ft 5 in.
Note: For Flash Protection Boundary, see 130.3(A).See definition in Article 100 and text in 130.2(D)(2) and Annex C for elaboration.
Limited Approach Boundary
Table 130.2(C) Approach Boundaries to Live Parts for Shock Protection. (All dimensionsare distance from live part to employee.)
Restricted Approach
Nominal System --------------------------------------------------- Boundary; Includes
Voltage Range, Phase to Phase
Exposed Movable Conductor
Exposed Fixed Circuit Part
Inadvertent Movement Adder
Prohibited Approach Boundary
Less than 50 Not specified Not specified Not specified Not specified
50 to 300 10 ft 0 in. 3 ft 6 in. Avoid contact Avoid contact
301 to 750 10 ft 0 in. 3 ft 6 in. 1 ft 0 in. 0 ft 1 in.
751 to 15 kV 10 ft 0 in. 5 ft 0 in. 2 ft 2 in. 0 ft 7 in.
15.1 kV to 36 kV 10 ft 0 in. 6 ft 0 in. 2 ft 7 in. 0ft 10 in.
36.1 kV to 46 kV 10 ft 0 in. 8 ft 0 in. 2 ft 9 in. 1 ft 5 in.
46.1 kV to 72.5 kV 10 ft 0 in. 8 ft 0 in. 3 ft 2 in. 2 ft 1 in.
72.6 kV to 121 kV 10 ft 8 in. 8 ft 0 in. 3 ft 3 in. 2 ft 8 in.
138 kV to 145 kV 11 ft 0 in. 10 ft 0 in. 3 ft 7 in. 3 ft 1 in.
161 kV to 169 kV 11 ft 8 in. 11 ft 8 in. 4 ft 0 in. 3 ft 6 in.
230 kV to 242 kV 13 ft 0 in. 13 ft 0 in. 5 ft 3 in. 4 ft 9 in.345 kV to 362 kV 15 ft 4 in. 15 ft 4 in. 8 ft 6 in. 8 ft 0 in.
500 kV to 550 kV 19 ft 0 in. 19 ft 0 in. 11 ft 3 in. 10 ft 9 in.
765 kV to 800 kV 23 ft 9 in. 23 ft 9 in. 14 ft 11 in. 14 ft 5 in.
Note: For Flash Protection Boundary, see 130.3(A).See definition in Article 100 and text in 130.2(D)(2) and Annex C for elaboration.
Limited Approach Boundary
Table 130.2(C) Approach Boundaries to Live Parts for Shock Protection. (All dimensionsare distance from live part to employee.)
Restricted Approach
Nominal System --------------------------------------------------- Boundary; Includes
Voltage Range, Phase to Phase
Exposed Movable Conductor
Exposed Fixed Circuit Part
Inadvertent Movement Adder
Prohibited Approach Boundary
Less than 50 Not specified Not specified Not specified Not specified
50 to 300 10 ft 0 in. 3 ft 6 in. Avoid contact Avoid contact
301 to 750 10 ft 0 in. 3 ft 6 in. 1 ft 0 in. 0 ft 1 in.
751 to 15 kV 10 ft 0 in. 5 ft 0 in. 2 ft 2 in. 0 ft 7 in.
15.1 kV to 36 kV 10 ft 0 in. 6 ft 0 in. 2 ft 7 in. 0ft 10 in.
36.1 kV to 46 kV 10 ft 0 in. 8 ft 0 in. 2 ft 9 in. 1 ft 5 in.
46.1 kV to 72.5 kV 10 ft 0 in. 8 ft 0 in. 3 ft 2 in. 2 ft 1 in.
72.6 kV to 121 kV 10 ft 8 in. 8 ft 0 in. 3 ft 3 in. 2 ft 8 in.
138 kV to 145 kV 11 ft 0 in. 10 ft 0 in. 3 ft 7 in. 3 ft 1 in.
161 kV to 169 kV 11 ft 8 in. 11 ft 8 in. 4 ft 0 in. 3 ft 6 in.
230 kV to 242 kV 13 ft 0 in. 13 ft 0 in. 5 ft 3 in. 4 ft 9 in.345 kV to 362 kV 15 ft 4 in. 15 ft 4 in. 8 ft 6 in. 8 ft 0 in.
500 kV to 550 kV 19 ft 0 in. 19 ft 0 in. 11 ft 3 in. 10 ft 9 in.
765 kV to 800 kV 23 ft 9 in. 23 ft 9 in. 14 ft 11 in. 14 ft 5 in.
Note: For Flash Protection Boundary, see 130.3(A).See definition in Article 100 and text in 130.2(D)(2) and Annex C for elaboration.
Limited Approach Boundary
Table 130.2(C) Approach Boundaries to Live Parts for Shock Protection. (All dimensionsare distance from live part to employee.)
Restricted Approach
Nominal System --------------------------------------------------- Boundary; Includes
Voltage Range, Phase to Phase
Exposed Movable Conductor
Exposed Fixed Circuit Part
Inadvertent Movement Adder
Prohibited Approach Boundary
Less than 50 Not specified Not specified Not specified Not specified
50 to 300 10 ft 0 in. 3 ft 6 in. Avoid contact Avoid contact
301 to 750 10 ft 0 in. 3 ft 6 in. 1 ft 0 in. 0 ft 1 in.
751 to 15 kV 10 ft 0 in. 5 ft 0 in. 2 ft 2 in. 0 ft 7 in.
15.1 kV to 36 kV 10 ft 0 in. 6 ft 0 in. 2 ft 7 in. 0ft 10 in.
36.1 kV to 46 kV 10 ft 0 in. 8 ft 0 in. 2 ft 9 in. 1 ft 5 in.
46.1 kV to 72.5 kV 10 ft 0 in. 8 ft 0 in. 3 ft 2 in. 2 ft 1 in.
72.6 kV to 121 kV 10 ft 8 in. 8 ft 0 in. 3 ft 3 in. 2 ft 8 in.
138 kV to 145 kV 11 ft 0 in. 10 ft 0 in. 3 ft 7 in. 3 ft 1 in.
161 kV to 169 kV 11 ft 8 in. 11 ft 8 in. 4 ft 0 in. 3 ft 6 in.
230 kV to 242 kV 13 ft 0 in. 13 ft 0 in. 5 ft 3 in. 4 ft 9 in.345 kV to 362 kV 15 ft 4 in. 15 ft 4 in. 8 ft 6 in. 8 ft 0 in.
500 kV to 550 kV 19 ft 0 in. 19 ft 0 in. 11 ft 3 in. 10 ft 9 in.
765 kV to 800 kV 23 ft 9 in. 23 ft 9 in. 14 ft 11 in. 14 ft 5 in.
Note: For Flash Protection Boundary, see 130.3(A).See definition in Article 100 and text in 130.2(D)(2) and Annex C for elaboration.
Limited Approach Boundary
Table 130.2(C) Approach Boundaries to Live Parts for Shock Protection. (All dimensionsare distance from live part to employee.)
Restricted Approach
Nominal System --------------------------------------------------- Boundary; Includes
Voltage Range, Phase to Phase
Exposed Movable Conductor
Exposed Fixed Circuit Part
Inadvertent Movement Adder
Prohibited Approach Boundary
Less than 50 Not specified Not specified Not specified Not specified50 to 300 10 ft 0 in. 3 ft 6 in. Avoid contact Avoid contact301 to 750 10 ft 0 in. 3 ft 6 in. 1 ft 0 in. 0 ft 1 in.
751 to 15 kV 10 ft 0 in. 5 ft 0 in. 2 ft 2 in. 0 ft 7 in.
15.1 kV to 36 kV 10 ft 0 in. 6 ft 0 in. 2 ft 7 in. 0ft 10 in.
36.1 kV to 46 kV 10 ft 0 in. 8 ft 0 in. 2 ft 9 in. 1 ft 5 in.
46.1 kV to 72.5 kV 10 ft 0 in. 8 ft 0 in. 3 ft 2 in. 2 ft 1 in.
72.6 kV to 121 kV 10 ft 8 in. 8 ft 0 in. 3 ft 3 in. 2 ft 8 in.
138 kV to 145 kV 11 ft 0 in. 10 ft 0 in. 3 ft 7 in. 3 ft 1 in.
161 kV to 169 kV 11 ft 8 in. 11 ft 8 in. 4 ft 0 in. 3 ft 6 in.
230 kV to 242 kV 13 ft 0 in. 13 ft 0 in. 5 ft 3 in. 4 ft 9 in.345 kV to 362 kV 15 ft 4 in. 15 ft 4 in. 8 ft 6 in. 8 ft 0 in.
500 kV to 550 kV 19 ft 0 in. 19 ft 0 in. 11 ft 3 in. 10 ft 9 in.
765 kV to 800 kV 23 ft 9 in. 23 ft 9 in. 14 ft 11 in. 14 ft 5 in.
Note: For Flash Protection Boundary, see 130.3(A).See definition in Article 100 and text in 130.2(D)(2) and Annex C for elaboration.
Limited Approach Boundary
Table 130.2(C) Approach Boundaries to Live Parts for Shock Protection. (All dimensionsare distance from live part to employee.)
Restricted Approach
Nominal System --------------------------------------------------- Boundary; Includes
Voltage Range, Phase to Phase
Exposed Movable Conductor
Exposed Fixed Circuit Part
Inadvertent Movement Adder
Prohibited Approach Boundary
Less than 50 Not specified Not specified Not specified Not specified
50 to 300 10 ft 0 in. 3 ft 6 in. Avoid contact Avoid contact301 to 750 10 ft 0 in. 3 ft 6 in. 1 ft 0 in. 0 ft 1 in.
751 to 15 kV 10 ft 0 in. 5 ft 0 in. 2 ft 2 in. 0 ft 7 in.
15.1 kV to 36 kV 10 ft 0 in. 6 ft 0 in. 2 ft 7 in. 0ft 10 in.
36.1 kV to 46 kV 10 ft 0 in. 8 ft 0 in. 2 ft 9 in. 1 ft 5 in.
46.1 kV to 72.5 kV 10 ft 0 in. 8 ft 0 in. 3 ft 2 in. 2 ft 1 in.
72.6 kV to 121 kV 10 ft 8 in. 8 ft 0 in. 3 ft 3 in. 2 ft 8 in.
138 kV to 145 kV 11 ft 0 in. 10 ft 0 in. 3 ft 7 in. 3 ft 1 in.
161 kV to 169 kV 11 ft 8 in. 11 ft 8 in. 4 ft 0 in. 3 ft 6 in.
230 kV to 242 kV 13 ft 0 in. 13 ft 0 in. 5 ft 3 in. 4 ft 9 in.345 kV to 362 kV 15 ft 4 in. 15 ft 4 in. 8 ft 6 in. 8 ft 0 in.
500 kV to 550 kV 19 ft 0 in. 19 ft 0 in. 11 ft 3 in. 10 ft 9 in.
765 kV to 800 kV 23 ft 9 in. 23 ft 9 in. 14 ft 11 in. 14 ft 5 in.
Note: For Flash Protection Boundary, see 130.3(A).See definition in Article 100 and text in 130.2(D)(2) and Annex C for elaboration.
Limited Approach Boundary
Table 130.2(C) Approach Boundaries to Live Parts for Shock Protection. (All dimensionsare distance from live part to employee.)
Restricted Approach
Nominal System --------------------------------------------------- Boundary; Includes
Voltage Range, Phase to Phase
Exposed Movable Conductor
Exposed Fixed Circuit Part
Inadvertent Movement Adder
Prohibited Approach Boundary
Less than 50 Not specified Not specified Not specified Not specified
50 to 300 10 ft 0 in. 3 ft 6 in. Avoid contact Avoid contact
301 to 750 10 ft 0 in. 3 ft 6 in. 1 ft 0 in. 0 ft 1 in.
751 to 15 kV 10 ft 0 in. 5 ft 0 in. 2 ft 2 in. 0 ft 7 in.15.1 kV to 36 kV 10 ft 0 in. 6 ft 0 in. 2 ft 7 in. 0ft 10 in.
36.1 kV to 46 kV 10 ft 0 in. 8 ft 0 in. 2 ft 9 in. 1 ft 5 in.
46.1 kV to 72.5 kV 10 ft 0 in. 8 ft 0 in. 3 ft 2 in. 2 ft 1 in.
72.6 kV to 121 kV 10 ft 8 in. 8 ft 0 in. 3 ft 3 in. 2 ft 8 in.
138 kV to 145 kV 11 ft 0 in. 10 ft 0 in. 3 ft 7 in. 3 ft 1 in.
161 kV to 169 kV 11 ft 8 in. 11 ft 8 in. 4 ft 0 in. 3 ft 6 in.
230 kV to 242 kV 13 ft 0 in. 13 ft 0 in. 5 ft 3 in. 4 ft 9 in.345 kV to 362 kV 15 ft 4 in. 15 ft 4 in. 8 ft 6 in. 8 ft 0 in.
500 kV to 550 kV 19 ft 0 in. 19 ft 0 in. 11 ft 3 in. 10 ft 9 in.
765 kV to 800 kV 23 ft 9 in. 23 ft 9 in. 14 ft 11 in. 14 ft 5 in.
Note: For Flash Protection Boundary, see 130.3(A).See definition in Article 100 and text in 130.2(D)(2) and Annex C for elaboration.
Limited Approach Boundary
Table 130.2(C) Approach Boundaries to Live Parts for Shock Protection. (All dimensionsare distance from live part to employee.)
Restricted Approach
Nominal System --------------------------------------------------- Boundary; Includes
Voltage Range, Phase to Phase
Exposed Movable Conductor
Exposed Fixed Circuit Part
Inadvertent Movement Adder
Prohibited Approach Boundary
Less than 50 Not specified Not specified Not specified Not specified
50 to 300 10 ft 0 in. 3 ft 6 in. Avoid contact Avoid contact
301 to 750 10 ft 0 in. 3 ft 6 in. 1 ft 0 in. 0 ft 1 in.
751 to 15 kV 10 ft 0 in. 5 ft 0 in. 2 ft 2 in. 0 ft 7 in.
15.1 kV to 36 kV 10 ft 0 in. 6 ft 0 in. 2 ft 7 in. 0ft 10 in.
36.1 kV to 46 kV 10 ft 0 in. 8 ft 0 in. 2 ft 9 in. 1 ft 5 in.
46.1 kV to 72.5 kV 10 ft 0 in. 8 ft 0 in. 3 ft 2 in. 2 ft 1 in.
72.6 kV to 121 kV 10 ft 8 in. 8 ft 0 in. 3 ft 3 in. 2 ft 8 in.
138 kV to 145 kV 11 ft 0 in. 10 ft 0 in. 3 ft 7 in. 3 ft 1 in.
161 kV to 169 kV 11 ft 8 in. 11 ft 8 in. 4 ft 0 in. 3 ft 6 in.
230 kV to 242 kV 13 ft 0 in. 13 ft 0 in. 5 ft 3 in. 4 ft 9 in.345 kV to 362 kV 15 ft 4 in. 15 ft 4 in. 8 ft 6 in. 8 ft 0 in.
500 kV to 550 kV 19 ft 0 in. 19 ft 0 in. 11 ft 3 in. 10 ft 9 in.
765 kV to 800 kV 23 ft 9 in. 23 ft 9 in. 14 ft 11 in. 14 ft 5 in.
Note: For Flash Protection Boundary, see 130.3(A).See definition in Article 100 and text in 130.2(D)(2) and Annex C for elaboration.
Limited Approach Boundary
FN000385/CR, Electrical Safety in the WorkplaceFN000385/CR, Electrical Safety in the Workplace 2121
Shock Protection BoundariesShock Protection BoundariesSystem Voltage Range
Phase to Phase
LimitedApproachBoundary
(Fixed Parts)
RestrictedApproachBoundary
ProhibitedApproachBoundary
Shock ProtectionInsulating PPE
50 to 300Including 120, 277 and 120/208
3 Ft 6 InAvoid
ContactAvoid
Contact
LAB - NoneRAB - Wear/Use if Contact LikelyPAB - Wear/Use if Contact Likely
301 to 750Including 480/277
3 Ft 6 In 1 Foot 1 InchLAB - None
RAB - Must WearPAB - Must Wear
751 to 15KIncluding 13.8K
5 Feet 2 Ft 2 In 7 InchesLAB - None
RAB - Must WearPAB - Must Wear
345K to 362K 15 Ft 4 In 8 Ft 6 In 8 FeetLAB - None
RAB - Must WearPAB - Must Wear
Within theLimited Approach Boundary
Within theRestricted Approach Boundary
Within theProhibited Approach Boundary
Shock Protection Boundaries and PPEFermilab Summary for NFPA 70E
Non-Qualified Worker Allowed Within Only if Advised and Escorted by a QW.Insulated Equipment/Tools if Contact Likely.
Only Qualified Worker Allowed Within.May Not Enter with Conductive Objects.
Body Parts Must be Insulated.
Consider Activity as Same as Working On.
FN000385/CR, Electrical Safety in the WorkplaceFN000385/CR, Electrical Safety in the Workplace 2222
Electrically Insulating GlovesElectrically Insulating GlovesGlove Classes by Use VoltageGlove Classes by Use Voltage
Procure Through Your Local D/S ES&H DepartmentProcure Through Your Local D/S ES&H Department
Gloves must be tested after every 6 months of use Gloves must be tested after every 6 months of use through Fermilab’s program (April 1 and October 1 are through Fermilab’s program (April 1 and October 1 are Scheduled Exchange Dates)Scheduled Exchange Dates)
Inspect gloves before each useInspect gloves before each use
Use Leather Protectors with Electrically Insulating Gloves Use Leather Protectors with Electrically Insulating Gloves
Class 00 500 voltsClass 00 500 volts Class 0 1,000 voltsClass 0 1,000 volts
Class 1 7,500 voltsClass 1 7,500 volts Class 2 17,000 voltsClass 2 17,000 volts
Class 3 26,500 voltsClass 3 26,500 volts Class 4 36,000 voltsClass 4 36,000 volts
FN000385/CR, Electrical Safety in the WorkplaceFN000385/CR, Electrical Safety in the Workplace 2323
Arc Flash Hazard AnalysisArc Flash Hazard Analysis
Determines if thermal hazard existsDetermines if thermal hazard exists– Identifies required protective equipmentIdentifies required protective equipment
Flash Protection BoundaryFlash Protection Boundary– Distance from an exposed live part within which Distance from an exposed live part within which
a person could receive a 2nd degree burn from a person could receive a 2nd degree burn from an arc-flashan arc-flash
– For systems 600 volts or less, the default For systems 600 volts or less, the default boundary is 4 feetboundary is 4 feet
FN000385/CR, Electrical Safety in the WorkplaceFN000385/CR, Electrical Safety in the Workplace 2424
Arc Flash Hazard AnalysisArc Flash Hazard Analysis
– For voltages above 600 volts, the Flash For voltages above 600 volts, the Flash Protection boundary can be calculated with the Protection boundary can be calculated with the general equationsgeneral equations
– DistanceDistancecircuit componentcircuit component = [2.65 x MVA = [2.65 x MVAbfbf x t] x t]1/21/2
– DistanceDistancetransformertransformer = [53 x MVA x t] = [53 x MVA x t]1/21/2
MVAMVAbfbf = bolted fault capacity available at point involved in mega = bolted fault capacity available at point involved in mega
volt-ampsvolt-amps
MVA = capacity rating of transformer in mega volt-ampsMVA = capacity rating of transformer in mega volt-amps
FN000385/CR, Electrical Safety in the WorkplaceFN000385/CR, Electrical Safety in the Workplace 2525
Arc Flash Hazard AnalysisArc Flash Hazard Analysis
Incident Energy Exposure CalculationIncident Energy Exposure Calculation– Requires Single Line Electrical Drawing (SLED)Requires Single Line Electrical Drawing (SLED)
available fault currentavailable fault current
conductor wire sizesconductor wire sizes
conductor distancesconductor distances
operating voltage of the systemoperating voltage of the system
trip time for fuses or circuit breakerstrip time for fuses or circuit breakers
arc fault is in open air or in a box arc fault is in open air or in a box
FN000385/CR, Electrical Safety in the WorkplaceFN000385/CR, Electrical Safety in the Workplace 2626
Table 130.7 (C)(9)(a)Table 130.7 (C)(9)(a)
Table 130.7(C)(9)(a) Hazard/Risk Category Classifications
Task (Assumes Equipment Is Energized, and Work Hazard/ Risk V-rated V-ratedIs Done Within the Flash Protection Boundary) Category Gloves Tools
Panelboards Rated 240 V and Below — Notes 1 and 3
Circuit breaker (CB) or fused switch operation with covers on 0 N N
CB or fused switch operation with covers off 0 N N
Work on energized parts, including voltage testing (LOTO) 1 Y Y
Remove/install CBs or fused switches 1 Y Y
Removal of bolted covers (to expose bare, energized parts) 1 N N
Opening hinged covers (to expose bare, energized parts) 0 N N
Panelboards or Switchboards Rated >240 V and upto 600 V (with molded case or insulated casecircuit breakers) — Notes 1 and 3
Circuit breaker (CB) or fused switch operation with covers on 0 N N
CB or fused switch operation with covers off 1 N N
Work on energized parts, including voltage testing (LOTO) 2* Y Y
Table 130.7(C)(9)(a) Hazard/Risk Category Classifications
Task (Assumes Equipment Is Energized, and Work Hazard/ Risk V-rated V-ratedIs Done Within the Flash Protection Boundary) Category Gloves Tools
Panelboards Rated 240 V and Below — Notes 1 and 3Circuit breaker (CB) or fused switch operation with covers on 0 N N
CB or fused switch operation with covers off 0 N N
Work on energized parts, including voltage testing (LOTO) 1 Y Y
Remove/install CBs or fused switches 1 Y Y
Removal of bolted covers (to expose bare, energized parts) 1 N N
Opening hinged covers (to expose bare, energized parts) 0 N N
Panelboards or Switchboards Rated >240 V and upto 600 V (with molded case or insulated casecircuit breakers) — Notes 1 and 3
Circuit breaker (CB) or fused switch operation with covers on 0 N N
CB or fused switch operation with covers off 1 N N
Work on energized parts, including voltage testing (LOTO) 2* Y Y
Table 130.7(C)(9)(a) Hazard/Risk Category Classifications
Task (Assumes Equipment Is Energized, and Work Hazard/ Risk V-rated V-ratedIs Done Within the Flash Protection Boundary) Category Gloves Tools
Panelboards Rated 240 V and Below — Notes 1 and 3
Circuit breaker (CB) or fused switch operation with covers on 0 N NCB or fused switch operation with covers off 0 N N
Work on energized parts, including voltage testing (LOTO) 1 Y Y
Remove/install CBs or fused switches 1 Y Y
Removal of bolted covers (to expose bare, energized parts) 1 N N
Opening hinged covers (to expose bare, energized parts) 0 N N
Panelboards or Switchboards Rated >240 V and upto 600 V (with molded case or insulated casecircuit breakers) — Notes 1 and 3
Circuit breaker (CB) or fused switch operation with covers on 0 N N
CB or fused switch operation with covers off 1 N N
Work on energized parts, including voltage testing (LOTO) 2* Y Y
Table 130.7(C)(9)(a) Hazard/Risk Category Classifications
Task (Assumes Equipment Is Energized, and Work Hazard/ Risk V-rated V-ratedIs Done Within the Flash Protection Boundary) Category Gloves Tools
Panelboards Rated 240 V and Below — Notes 1 and 3
Circuit breaker (CB) or fused switch operation with covers on 0 N N
CB or fused switch operation with covers off 0 N N
Work on energized parts, including voltage testing (LOTO) 1 Y Y
Remove/install CBs or fused switches 1 Y Y
Removal of bolted covers (to expose bare, energized parts) 1 N N
Opening hinged covers (to expose bare, energized parts) 0 N N
Panelboards or Switchboards Rated >240 V and upto 600 V (with molded case or insulated casecircuit breakers) — Notes 1 and 3Circuit breaker (CB) or fused switch operation with covers on 0 N N
CB or fused switch operation with covers off 1 N N
Work on energized parts, including voltage testing (LOTO) 2* Y Y
Table 130.7(C)(9)(a) Hazard/Risk Category Classifications
Task (Assumes Equipment Is Energized, and Work Hazard/ Risk V-rated V-ratedIs Done Within the Flash Protection Boundary) Category Gloves Tools
Panelboards Rated 240 V and Below — Notes 1 and 3
Circuit breaker (CB) or fused switch operation with covers on 0 N N
CB or fused switch operation with covers off 0 N N
Work on energized parts, including voltage testing (LOTO) 1 Y Y
Remove/install CBs or fused switches 1 Y Y
Removal of bolted covers (to expose bare, energized parts) 1 N N
Opening hinged covers (to expose bare, energized parts) 0 N N
Panelboards or Switchboards Rated >240 V and upto 600 V (with molded case or insulated casecircuit breakers) — Notes 1 and 3Circuit breaker (CB) or fused switch operation with covers on 0 N N
CB or fused switch operation with covers off 1 N NWork on energized parts, including voltage testing (LOTO) 2* Y Y
Table 130.7(C)(9)(a) Hazard/Risk Category Classifications
Task (Assumes Equipment Is Energized, and Work Hazard/ Risk V-rated V-ratedIs Done Within the Flash Protection Boundary) Category Gloves Tools
Panelboards Rated 240 V and Below — Notes 1 and 3Circuit breaker (CB) or fused switch operation with covers on 0 N N
CB or fused switch operation with covers off 0 N N
Work on energized parts, including voltage testing (LOTO) 1 Y Y
Remove/install CBs or fused switches 1 Y Y
Removal of bolted covers (to expose bare, energized parts) 1 N N
Opening hinged covers (to expose bare, energized parts) 0 N N
Panelboards or Switchboards Rated >240 V and upto 600 V (with molded case or insulated case
circuit breakers) — Notes 1 and 3Circuit breaker (CB) or fused switch operation with covers on 0 N N
CB or fused switch operation with covers off 1 N N
Work on energized parts, including voltage testing (LOTO) 2* Y Y
FN000385/CR, Electrical Safety in the WorkplaceFN000385/CR, Electrical Safety in the Workplace 2727
Table 130.7 (C)(9)(a)Table 130.7 (C)(9)(a)
Footnotes 1 and 3Footnotes 1 and 3
– Footnote #1 Footnote #1 25 kA short circuit current available, 0.03 25 kA short circuit current available, 0.03 second (2 cycle) fault clearing time.second (2 cycle) fault clearing time.
– Footnote #3Footnote #3For < 10 kA short circuit current available, the For < 10 kA short circuit current available, the hazard/risk category required may be reduced hazard/risk category required may be reduced by one number.by one number.
FN000385/CR, Electrical Safety in the WorkplaceFN000385/CR, Electrical Safety in the Workplace 2828
Table 130.7 (C)(9)(a)Table 130.7 (C)(9)(a)
Table 130.7(C)(9)(a) Hazard/Risk Category Classifications
Task (Assumes Equipment Is Energized, and Work Hazard/ Risk V-rated V-ratedIs Done Within the Flash Protection Boundary) Category Gloves Tools
600 V Class Motor Control Centers (MCC) -Notes 2 (except as indicated) and 3
CB or fused switch or starter operation with enclosure doors closed 0 N N
Reading a panel meter while operating a meter switch 0 N N
CB or fused switch or starter operation with enclosure doors open 1 N N
Work on energized parts, including voltage testing (LOTO) 2* Y Y
Work on control circuits with energized parts 120 V or below, exposed 0 Y Y
Work on control circuits with energized parts >120 V, exposed 2* Y Y
Insertion or removal of individual starter “buckets” from MCC - Note 4 3 Y N
Application of safety grounds, after voltage test 2* Y N
Removal of bolted covers (to expose bare, energized parts) 2* N N
Opening hinged covers (to expose bare, energized parts) 1 N N
Table 130.7(C)(9)(a) Hazard/Risk Category Classifications
Task (Assumes Equipment Is Energized, and Work Hazard/ Risk V-rated V-ratedIs Done Within the Flash Protection Boundary) Category Gloves Tools
600 V Class Motor Control Centers (MCC) -Notes 2 (except as indicated) and 3
CB or fused switch or starter operation with enclosure doors closed 0 N N
Reading a panel meter while operating a meter switch 0 N N
CB or fused switch or starter operation with enclosure doors open 1 N N
Work on energized parts, including voltage testing (LOTO) 2* Y YWork on control circuits with energized parts 120 V or below, exposed 0 Y Y
Work on control circuits with energized parts >120 V, exposed 2* Y Y
Insertion or removal of individual starter “buckets” from MCC - Note 4 3 Y N
Application of safety grounds, after voltage test 2* Y N
Removal of bolted covers (to expose bare, energized parts) 2* N N
Opening hinged covers (to expose bare, energized parts) 1 N N
FN000385/CR, Electrical Safety in the WorkplaceFN000385/CR, Electrical Safety in the Workplace 2929
Hazard Risk ClasificationHazard Risk ClasificationEquipment Voltage
Rated Full Load
Current
Hazard/RiskCategory
Conditions or Qualifications
Primary PanelboardsSWBD DHP
480/277 VACMore than
1,200 Amps 3
Primary Transformer Larger than 1000 KVA(Assuming More Than 25,000 ISC Available
with Fault Clearing Time >2 Cycles)Take Advantage of Installed Panelboard Meter for LOTO
Verification if Present.
Motor Control CentersMCC
480 VACTypical 600 Amps and
Above2* Take Advantage of Installed Central Monitoring Unit for LOTO
Verification if Present
Primary or Secondary PanelboardsDHP PHP LP
480/277 VAC400 to 1,200
Amps 2* Proximity to Transformer Power Source Presumed
Operating 13.8 KV Disconnectswith Doors Closed
13.8 KV NA 2 Booster Brentford or RF Anode Power Suppliesare Examples
Secondary PanelboardsPHP LP
480/277 VAC100 to 225
Amps 1Assuming Less Than 10,000 ISC Available
More Than 200 Feet from Panelboard Sourcing Power
Lighting PanelboardsLP
480/277 VAC 100 Amps 1Assuming Less Than 10,000 ISC Available
More Than 100 Feet from Secondary Panelboard Sourcing Power
Utility Panelboards120/208 VAC120/240 VAC
Below 400 Amps 0
No Known Fault Currents Above 10,000 Amps.Knowing Transformer KVA and %IZ, Apply Formula for
Suspect Installations
480/277 VAC NA 0 Requirement Direct from NFPA 70E C9 Table
120/208 VAC120/240 VAC
NA -1No Known Fault Currents Above 10,000 Amps.
Knowing Transformer KVA and %IZ, Apply Formula for Suspect Installations
Simplified Guidance for Electrical Work on Fermilab AC POWER DISTRIBUTION EquipmentDiagnostic Work Including LOTO Voltage Testing Unless Otherwise Noted, Plus Some Additional Operations
This Simplified Table for AC Power Distribution Equipment Has Been Approved by the Electrical Safety Subcommittee. Guidance Assumes the Transformer Powering the AC Power Distribution System Has an Impedance in the Range of 4.5 to 6 %IZ.
If Stated Conditions or Qualifications Are Not Met or the Circumstances of the Work Activity Appear Unique, Refer to NFPA 70E Table 130.7(C)(9)(a) or Consult with Your D/S Electrical Coordinator.
Operating Circuit Breakersand Disconnect Switcheswith Covers On or Closed
Equipment VoltageRated Full
Load Current
Hazard/RiskCategory
Conditions or Qualifications
Primary PanelboardsSWBD DHP
480/277 VACMore than
1,200 Amps 3
Primary Transformer Larger than 1000 KVA(Assuming More Than 25,000 ISC Available
with Fault Clearing Time >2 Cycles)Take Advantage of Installed Panelboard Meter for LOTO
Verification if Present.
Motor Control CentersMCC
480 VACTypical 600 Amps and
Above2* Take Advantage of Installed Central Monitoring Unit for LOTO
Verification if Present
Primary or Secondary PanelboardsDHP PHP LP
480/277 VAC400 to 1,200
Amps 2* Proximity to Transformer Power Source Presumed
Operating 13.8 KV Disconnectswith Doors Closed
13.8 KV NA 2 Booster Brentford or RF Anode Power Suppliesare Examples
Secondary PanelboardsPHP LP
480/277 VAC100 to 225
Amps 1Assuming Less Than 10,000 ISC Available
More Than 200 Feet from Panelboard Sourcing Power
Lighting PanelboardsLP
480/277 VAC 100 Amps 1Assuming Less Than 10,000 ISC Available
More Than 100 Feet from Secondary Panelboard Sourcing Power
Utility Panelboards120/208 VAC120/240 VAC
Below 400 Amps 0
No Known Fault Currents Above 10,000 Amps.Knowing Transformer KVA and %IZ, Apply Formula for
Suspect Installations
480/277 VAC NA 0 Requirement Direct from NFPA 70E C9 Table
120/208 VAC120/240 VAC
NA -1No Known Fault Currents Above 10,000 Amps.
Knowing Transformer KVA and %IZ, Apply Formula for Suspect Installations
Simplified Guidance for Electrical Work on Fermilab AC POWER DISTRIBUTION EquipmentDiagnostic Work Including LOTO Voltage Testing Unless Otherwise Noted, Plus Some Additional Operations
This Simplified Table for AC Power Distribution Equipment Has Been Approved by the Electrical Safety Subcommittee. Guidance Assumes the Transformer Powering the AC Power Distribution System Has an Impedance in the Range of 4.5 to 6 %IZ.
If Stated Conditions or Qualifications Are Not Met or the Circumstances of the Work Activity Appear Unique, Refer to NFPA 70E Table 130.7(C)(9)(a) or Consult with Your D/S Electrical Coordinator.
Operating Circuit Breakersand Disconnect Switcheswith Covers On or Closed
FN000385/CR, Electrical Safety in the WorkplaceFN000385/CR, Electrical Safety in the Workplace 3030
Hazard Risk ClasificationHazard Risk ClasificationEquipment Voltage
Sourcing Branch CB
Hazard/RiskCategory
Conditions or Qualifications
Power Supplies 480 VAC VariousCan Range from
0 to 3
Ask Your Department for an Assessment.Take Advantage of Installed Panel Meters for LOTO
Verification.
Various Equipment480 VAC or
480/277 VAC100 to Less
than 400 Amps 2 Distance from Primary Panelboards and Feed Conductors Limit Available Fault Currents
Various Equipment480 VAC or
480/277 VACLess Than 100
Amps 1 Distance from Primary Panelboards and Feed Conductors Limit Available Fault Currents
Sump Pump Controllers Motor ControllersHVAC Equipment
480 VAC60 Amps and
Below 1 Distance from Primary Panelboards and Feed Conductors Limit Available Fault Currents
Ballasts and Light Fixtures 277 VAC30 Amps and
Below 0 Typical Lighting Ballast
Power Supplies 208 VAC225 Amps and
Below 0No Known Fault Currents Above 10,000 Amps. Knowing Transformer KVA and %IZ, Apply Formula for Suspect
Installations
Various Equipment 120/208 VAC225 Amps and
Below 0No Known Fault Currents Above 10,000 Amps. Knowing Transformer KVA and %IZ, Apply Formula for Suspect
Installations
Various Equipment 120 VAC30 Amps and
Below -1 Bench Testing.No Known Fault Currents Above 10,000 Amps.
Simplified Guidance for Electrical Work on Fermilab UTILIZATION EquipmentDiagnostic Work Including LOTO Voltage Testing Unless Otherwise Noted
This Simplified Table for Utilization Equipment Has Been Approved by the Electrical Safety Subcommittee. Guidance Assumes the Transformer Powering the AC Power Distribution System Has an Impedance in the Range of 4.5 to 6 %IZ.
If Stated Conditions or Qualifications Are Not Met or the Circumstances of the Work Activity Appear Unique, Refer to NFPA 70E Table 130.7(C)(9)(a) or Consult with Your D/S Electrical Coordinator.
Equipment VoltageSourcing
Branch CBHazard/Risk
CategoryConditions or Qualifications
Power Supplies 480 VAC VariousCan Range from
0 to 3
Ask Your Department for an Assessment.Take Advantage of Installed Panel Meters for LOTO
Verification.
Various Equipment480 VAC or
480/277 VAC100 to Less
than 400 Amps 2 Distance from Primary Panelboards and Feed Conductors Limit Available Fault Currents
Various Equipment480 VAC or
480/277 VACLess Than 100
Amps 1 Distance from Primary Panelboards and Feed Conductors Limit Available Fault Currents
Sump Pump Controllers Motor ControllersHVAC Equipment
480 VAC60 Amps and
Below 1 Distance from Primary Panelboards and Feed Conductors Limit Available Fault Currents
Ballasts and Light Fixtures 277 VAC30 Amps and
Below 0 Typical Lighting Ballast
Power Supplies 208 VAC225 Amps and
Below 0No Known Fault Currents Above 10,000 Amps. Knowing
Transformer KVA and %IZ, Apply Formula for Suspect Installations
Various Equipment 120/208 VAC225 Amps and
Below 0No Known Fault Currents Above 10,000 Amps. Knowing Transformer KVA and %IZ, Apply Formula for Suspect
Installations
Various Equipment 120 VAC30 Amps and
Below -1 Bench Testing.No Known Fault Currents Above 10,000 Amps.
Simplified Guidance for Electrical Work on Fermilab UTILIZATION EquipmentDiagnostic Work Including LOTO Voltage Testing Unless Otherwise Noted
This Simplified Table for Utilization Equipment Has Been Approved by the Electrical Safety Subcommittee. Guidance Assumes the Transformer Powering the AC Power Distribution System Has an Impedance in the Range of 4.5 to 6 %IZ.
If Stated Conditions or Qualifications Are Not Met or the Circumstances of the Work Activity Appear Unique, Refer to NFPA 70E Table 130.7(C)(9)(a) or Consult with Your D/S Electrical Coordinator.
FN000385/CR, Electrical Safety in the WorkplaceFN000385/CR, Electrical Safety in the Workplace 3131
Arc-Flash Protective ClothingArc-Flash Protective Clothing
Hazard Category defines required PPEHazard Category defines required PPE
NFPA 70E Table 130.7(C)(10)NFPA 70E Table 130.7(C)(10)
Fermilab Summary for NFPA 70E Arc-Flash Fermilab Summary for NFPA 70E Arc-Flash Hazard/Risk CategoriesHazard/Risk Categories
FN000385/CR, Electrical Safety in the WorkplaceFN000385/CR, Electrical Safety in the Workplace 3232
Arc-Flash Protective ClothingArc-Flash Protective Clothing
Table 130.7(C)(10) Protective Clothing and Personal Protective Equipment (PPE) Matrix
Protective Clothing and Equipment
Hazard/Risk Category Number —1 0 1 2 3 4(Note 3)
Non-melting (according to ASTM F1506-00) or Untreated Natural Fiber
a. T-shirt (short-sleeve) X X X Xb. Shirt (long-sleeve) Xc. Pants (long) X X X X X X
(Note 4) (Note 6)
FR Clothing (Note 1)
a. Long-sleeve shirt X X X X(Note 9)
b. Pants X X X X(Note 4) (Note 6) (Note 9)
c. Coverall (Note 5) (Note 7) X (Note 5)(Note 9)
d. Jacket, parka, or rainwear AN AN AN AN
FR Protective Equipmenta. Flash suit jacket (multilayer) Xb. Flash suit pants (multilayer) Xc. Head protection
1. Hardhat X X X X2. FR hard hat liner AR AR
d. Eye protection - - - - -1. Safety glasses X X X AL AL AL2. Safety goggles AL AL AL
e. Face and head area protection - - - -1. Arc-rated face shield, or flash suit hood X
(Note 8)2. Flash suit hood X X3. Hearing protection (ear canal inserts) X X X
(Note 8)f. Hand protection - - - -
Leather gloves (Note 2) AN X X Xg. Foot protection
Leather work shoes AN X X X
AN = As neededAL = Select one in groupAR = As requiredX = Minimum required
Protective Systems for Hazard/Risk Category
Table 130.7(C)(10) Protective Clothing and Personal Protective Equipment (PPE) Matrix
Protective Clothing and Equipment
Hazard/Risk Category Number —1 0 1 2 3 4(Note 3)
Non-melting (according to ASTM F1506-00) or Untreated Natural Fiber
a. T-shirt (short-sleeve) X X X Xb. Shirt (long-sleeve) Xc. Pants (long) X X X X X X
(Note 4) (Note 6)
FR Clothing (Note 1)
a. Long-sleeve shirt X X X X(Note 9)
b. Pants X X X X(Note 4) (Note 6) (Note 9)
c. Coverall (Note 5) (Note 7) X (Note 5)(Note 9)
d. Jacket, parka, or rainwear AN AN AN AN
FR Protective Equipmenta. Flash suit jacket (multilayer) Xb. Flash suit pants (multilayer) Xc. Head protection
1. Hardhat X X X X2. FR hard hat liner AR AR
d. Eye protection - - - - -1. Safety glasses X X X AL AL AL2. Safety goggles AL AL AL
e. Face and head area protection - - - -1. Arc-rated face shield, or flash suit hood X
(Note 8)2. Flash suit hood X X3. Hearing protection (ear canal inserts) X X X
(Note 8)f. Hand protection - - - -
Leather gloves (Note 2) AN X X Xg. Foot protection
Leather work shoes AN X X X
AN = As neededAL = Select one in groupAR = As requiredX = Minimum required
Protective Systems for Hazard/Risk Category
FN000385/CR, Electrical Safety in the WorkplaceFN000385/CR, Electrical Safety in the Workplace 3333
Arc-Flash Protective ClothingArc-Flash Protective ClothingCalculated Exposure
from Prospective Arc-FlashHazard/Risk
Category
MinimumRequired
ATPVClothing Requirements Additional PPE
Zero up to 1.2 cal/cm2 -1 NA Cotton Tee Shirt and Pants Safety Glasses
Zero up to 1.2 cal/cm2 0 NA Long Sleeve Cotton Shirt and Pants Safety Glasses
More than 1.2 and up to 4 cal/cm2 1 4 cal/cm2 FR Coverall* Hard Hat, Safety Glasses
More than 4 and up to 8 cal/cm2 2 8 cal/cm2 Cotton Clothing Under FR Coverall*
Hard Hat, Safety Glasses,Face Shield,
Hearing Protection, Leather Gloves,Leather Work Shoes
More than 4 and up to 8 cal/cm2 2* 8 cal/cm2 Cotton Clothing Under FR Coverall*
Hard Hat, Safety Glasses,Double-Layer Switching Hood,
Hearing Protection, Leather Gloves,Leather Work Shoes
More than 8 and up to 25 cal/cm2 3 25 cal/cm2 Cotton Clothing Under 2 x FR Coveralls*
Hard Hat, Safety Glasses,Flash Suit Hood,
Hearing Protection, Leather Gloves,Leather Work Shoes
More than 25 and up tp 40 cal/cm2 4 40 cal/cm2 Cotton Clothing Under FR Coverall*plus Multilayer Flash Suit Jacket & Pants
Hard Hat, Safety Glasses,Flash Suit Hood,
Hearing Protection, Leather Gloves,Leather Work Shoes
Arc-Flash Hazard/Risk Categories - Required Clothing - Required PPEFermilab Summary for NFPA 70E
* Coverall Rated at 8 cal/cm2 Available from Fermilab Stockroom
Calculated Exposurefrom Prospective Arc-Flash
Hazard/RiskCategory
MinimumRequired
ATPVClothing Requirements Additional PPE
Zero up to 1.2 cal/cm2 -1 NA Cotton Tee Shirt and Pants Safety Glasses
Zero up to 1.2 cal/cm2 0 NA Long Sleeve Cotton Shirt and Pants Safety Glasses
More than 1.2 and up to 4 cal/cm2 1 4 cal/cm2 FR Coverall* Hard Hat, Safety Glasses
More than 4 and up to 8 cal/cm2 2 8 cal/cm2 Cotton Clothing Under FR Coverall*
Hard Hat, Safety Glasses,Face Shield,
Hearing Protection, Leather Gloves,Leather Work Shoes
More than 4 and up to 8 cal/cm2 2* 8 cal/cm2 Cotton Clothing Under FR Coverall*
Hard Hat, Safety Glasses,Double-Layer Switching Hood,
Hearing Protection, Leather Gloves,Leather Work Shoes
More than 8 and up to 25 cal/cm2 3 25 cal/cm2 Cotton Clothing Under 2 x FR Coveralls*
Hard Hat, Safety Glasses,Flash Suit Hood,
Hearing Protection, Leather Gloves,Leather Work Shoes
More than 25 and up tp 40 cal/cm2 4 40 cal/cm2 Cotton Clothing Under FR Coverall*plus Multilayer Flash Suit Jacket & Pants
Hard Hat, Safety Glasses,Flash Suit Hood,
Hearing Protection, Leather Gloves,Leather Work Shoes
Arc-Flash Hazard/Risk Categories - Required Clothing - Required PPEFermilab Summary for NFPA 70E
* Coverall Rated at 8 cal/cm2 Available from Fermilab Stockroom
Calculated Exposurefrom Prospective Arc-Flash
Hazard/RiskCategory
MinimumRequired
ATPVClothing Requirements Additional PPE
Zero up to 1.2 cal/cm2 -1 NA Cotton Tee Shirt and Pants Safety Glasses
Zero up to 1.2 cal/cm2 0 NA Long Sleeve Cotton Shirt and Pants Safety Glasses
More than 1.2 and up to 4 cal/cm2 1 4 cal/cm2 FR Coverall* Hard Hat, Safety Glasses
More than 4 and up to 8 cal/cm2 2 8 cal/cm2 Cotton Clothing Under FR Coverall*
Hard Hat, Safety Glasses,Face Shield,
Hearing Protection, Leather Gloves,Leather Work Shoes
More than 4 and up to 8 cal/cm2 2* 8 cal/cm2 Cotton Clothing Under FR Coverall*
Hard Hat, Safety Glasses,Double-Layer Switching Hood,
Hearing Protection, Leather Gloves,Leather Work Shoes
More than 8 and up to 25 cal/cm2 3 25 cal/cm2 Cotton Clothing Under 2 x FR Coveralls*
Hard Hat, Safety Glasses,Flash Suit Hood,
Hearing Protection, Leather Gloves,Leather Work Shoes
More than 25 and up tp 40 cal/cm2 4 40 cal/cm2 Cotton Clothing Under FR Coverall*plus Multilayer Flash Suit Jacket & Pants
Hard Hat, Safety Glasses,Flash Suit Hood,
Hearing Protection, Leather Gloves,Leather Work Shoes
Arc-Flash Hazard/Risk Categories - Required Clothing - Required PPEFermilab Summary for NFPA 70E
* Coverall Rated at 8 cal/cm2 Available from Fermilab Stockroom
FN000385/CR, Electrical Safety in the WorkplaceFN000385/CR, Electrical Safety in the Workplace 3434
Arc-Flash PPEArc-Flash PPE
All Hazard Risk Categories Require All Hazard Risk Categories Require Eye ProtectionEye Protection
Hazard Risk Categories 1 and up requireHazard Risk Categories 1 and up require– Hard Hats, Leather Gloves, Leather Shoes, andHard Hats, Leather Gloves, Leather Shoes, and
Fire Resistant rated protective clothing Fire Resistant rated protective clothing
Hazard Risk Categories 2 and up requireHazard Risk Categories 2 and up require– Arc-rated face shield or flash suit hood andArc-rated face shield or flash suit hood and
Hearing ProtectionHearing Protection
FN000385/CR, Electrical Safety in the WorkplaceFN000385/CR, Electrical Safety in the Workplace 3535
Fire Resistant (FR) ClothingFire Resistant (FR) Clothing
Hazard/Risk Category 1 or above, fire Hazard/Risk Category 1 or above, fire resistant or FR clothing is requiredresistant or FR clothing is requiredArc Thermal Protection Value (ATPV) Arc Thermal Protection Value (ATPV)
– Identifies maximum thermal protection the Identifies maximum thermal protection the clothing can provide.clothing can provide.
– PPE such as face shields, hoods, jackets, PPE such as face shields, hoods, jackets, coats, and coveralls have an ATPV ratingcoats, and coveralls have an ATPV rating
Select clothing and equipment that meets or Select clothing and equipment that meets or exceeds minimum ATPV required for the exceeds minimum ATPV required for the Hazard/Risk Category Hazard/Risk Category
FN000385/CR, Electrical Safety in the WorkplaceFN000385/CR, Electrical Safety in the Workplace 3636
Fire Resistant (FR) ClothingFire Resistant (FR) Clothing
Wear and care of PPEWear and care of PPE– Wear cotton or natural fiber non melting Wear cotton or natural fiber non melting
clothingclothing– Wear PPE that satisfies the minimum ATPV Wear PPE that satisfies the minimum ATPV
requiredrequired– Layering clothing increases protectionLayering clothing increases protection– Wear clothing loose rather than tightWear clothing loose rather than tight
Do not use bleach or fabric softeners on Do not use bleach or fabric softeners on ATPV rated PPEATPV rated PPE
FN000385/CR, Electrical Safety in the WorkplaceFN000385/CR, Electrical Safety in the Workplace 3737
Electrical Safe Work ConditionElectrical Safe Work ConditionDetermine all possible power sourcesDetermine all possible power sources
Electrical Hazard AnalysisElectrical Hazard Analysis– Shock Hazard AnalysisShock Hazard Analysis
Limited, Restricted, and ProhibitedLimited, Restricted, and ProhibitedApproach BoundariesApproach Boundaries
Shock protection PPEShock protection PPE
– Arc-Flash Hazard AnalysisArc-Flash Hazard AnalysisHazard Risk CategoryHazard Risk Category
Arc-Flash PPEArc-Flash PPE
Flash Protection BoundaryFlash Protection Boundary
FN000385/CR, Electrical Safety in the WorkplaceFN000385/CR, Electrical Safety in the Workplace 3838
Electrical Safe Work ConditionElectrical Safe Work ConditionPlan for EmergenciesPlan for Emergencies
– Know how to de-energize quicklyKnow how to de-energize quickly– Be prepared to pull employee free with an Be prepared to pull employee free with an
insulated rescue hookinsulated rescue hook– Means available to call 3131Means available to call 3131– Know CPR and where AED’s are locatedKnow CPR and where AED’s are located
Protect unqualified persons from work areaProtect unqualified persons from work area
Don the appropriate PPEDon the appropriate PPE
FN000385/CR, Electrical Safety in the WorkplaceFN000385/CR, Electrical Safety in the Workplace 3939
Electrical Safe Work ConditionElectrical Safe Work Condition
Open disconnect deviceOpen disconnect device
Perform LOTO Perform LOTO – Verification is the most important stepVerification is the most important step
F4 Service Building 13.8 KV Disconnect F4 Service Building 13.8 KV Disconnect switch failure occurred on Wed Oct 1, 2008switch failure occurred on Wed Oct 1, 2008
FN000385/CR, Electrical Safety in the WorkplaceFN000385/CR, Electrical Safety in the Workplace 4040
Electrical Safe Work ConditionElectrical Safe Work Condition– Voltage Testing (LOTO)Voltage Testing (LOTO)
Use a meter rated for the taskUse a meter rated for the task– Test meter both before and after use when performing Test meter both before and after use when performing
LOTOLOTO– Common observation –Common observation –
People don’t check their meter after performing LOTOPeople don’t check their meter after performing LOTO– Proximity sensors are not to be used for LOTOProximity sensors are not to be used for LOTO
– Ground stored energy devices and potential Ground stored energy devices and potential induced voltage sourcesinduced voltage sources
FN000385/CR, Electrical Safety in the WorkplaceFN000385/CR, Electrical Safety in the Workplace 4141
QuestionsQuestionsResourcesResources
– Fermilab Electrical Safety SubcommitteeFermilab Electrical Safety Subcommittee– Division/Section Senior Safety OfficerDivision/Section Senior Safety Officer– Division/Section Electrical CoordinatorDivision/Section Electrical Coordinator– Line ManagementLine Management
Fermilab Summary Guidance SheetsFermilab Summary Guidance Sheets– http://www-esh.fnal.gov/pls/default/esh_home_page.page?this_page=22152http://www-esh.fnal.gov/pls/default/esh_home_page.page?this_page=22152
Enroll in the challenge examEnroll in the challenge exam– http://www-esh.fnal.gov/pls/default/esh_tests.htmlhttp://www-esh.fnal.gov/pls/default/esh_tests.html
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