Transcript Electrical Safety in the Workplace

Electrical Safety in the
Workplace
FN000385/CR
Overview
NFPA 70E Objectives
Electrical Hazards
Mitigation of Hazards
Electrical Work Activities
– Diagnostic vs. Manipulative
FN000385/CR, Electrical Safety in the Workplace
2
Overview
Fermilab Electrical Safety Policy
Electrical Hazard Analysis
–
–
Shock Hazard Analysis
Arc Flash Hazard Analysis
Establishing an Electrically Safe Work
Condition
Additional Resources
FN000385/CR, Electrical Safety in the Workplace
3
NFPA 70E Objectives
Protect workers from electrical shock and
arc-flash hazards
Understand the work and associated
electrical hazards
Understand the PPE requirements for
electrical shock protection and
arc-flash protection
FN000385/CR, Electrical Safety in the Workplace
4
Electrical Hazards
Three Main Hazards
–
Electric Shock
–
Arc-Flash
–
Arc Blast
FN000385/CR, Electrical Safety in the Workplace
5
Electrical Hazards
Electric Shock
–
–
–
–
–
–
Electric current passes through the body
1 milliamp can feel the current
15 milliamps can’t let go of electrical source
100 milliamps through chest can result in
ventricular fibrillation which is usually fatal
Automatic External Defibrillator (AED)
only practical way to return heart to normal
rhythm
Deep tissue burns
FN000385/CR, Electrical Safety in the Workplace
6
Electrical Hazards
Arc Flash
–
–
Electric current passes through air,
between a “Hot” conductor and ground,
or between “Hot” conductors
Severity is determined by
Available fault current
Conductor size
Time or duration
–
Temperatures can reach 35,000 Degrees F
roughly three times the surface temperature of
the sun
FN000385/CR, Electrical Safety in the Workplace
7
Electrical Hazards
Arc Flash
–
–
–
–
Clothing or PPE that burns and melts to the
body is the most serious concern
203 Degrees F for 0.1 seconds results in third
degree burn
The incident energy threshold for the onset of a
second degree burn is 1.2 cal/cm2.
Exposure can easily cause skin burns and
ignite clothing
FN000385/CR, Electrical Safety in the Workplace
8
Electrical Hazards
Arc Blast
–
Rapid expansion of air caused by an electrical
arc
Caused by two sources
–
–
Metal boiling and vaporizing
Heating of air from the arc
Copper expands by a factor of 67,000 times when
vaporized
Best categorized as an explosion
–
–
–
Hearing loss due to blast explosion
Lacerations/Punctures from blast debris
Trauma from percussion force
FN000385/CR, Electrical Safety in the Workplace
9
Electrical Hazards
1997 F0 Compressor Room 480 volt MCC Arc Flash Event
FN000385/CR, Electrical Safety in the Workplace
10
Mitigation of Hazards
Arc Blast
–
–
–
Work De-Energized
Engineer Out the Hazard
Follow Safe Work Practices
Electrical Hazard Analysis
Employ Lockout/Tagout of Hazardous Electrical
Energy Sources
Use Voltage Insulating PPE and Equipment
Use PPE for Arc-Flash Protection
Use Ground Fault Circuit Interrupters
FN000385/CR, Electrical Safety in the Workplace
11
Diagnostic vs. Manipulative Work
Diagnostic
–
–
–
Inspection, testing, voltage and/or current
measurements, phase alignment,
troubleshooting, circuit and signal tracing,
thermal imaging, etc. that are performed on or
near exposed live parts within the Limited
Approach Boundary
Verification Associated with LOTO
Performed by Qualified Persons utilizing
appropriately rated measurement equipment
and required PPE.
FN000385/CR, Electrical Safety in the Workplace
12
Diagnostic vs. Manipulative Work
Manipulative
–
–
Making, tightening or breaking of energized
electrical connections or the replacement,
removal, or addition of electrical or mechanical
components
Examples include:
Replacing a duplex outlet, light switch, fluorescent
fixture ballast, fuses, circuit breakers
Drilling or punching holes in a live panelboard
Pulling conductors into a live panelboard
FN000385/CR, Electrical Safety in the Workplace
13
Fermilab Policy
Do Not work on energized electrical
equipment unless absolutely necessary.
Diagnostic Energized Work is allowed only
when the diagnostic activity is not feasible
with the circuit de-energized.
Manipulative Energized Work is prohibited
at Fermilab unless it can be demonstrated
that de-energization introduces additional or
increased hazards or is infeasible due to
equipment design or operational limitations
FN000385/CR, Electrical Safety in the Workplace
14
Fermilab Policy
Infeasible does not include Inconvenient
Directorate Approval Required for
Manipulative Energized Work
Fermilab policies and NFPA 70E apply to
both the AC Power Distribution system and
to Utilization Equipment
FN000385/CR, Electrical Safety in the Workplace
15
Electrical Hazard Analysis
Shock Hazard Analysis
Arc-Flash Hazard Analysis
FN000385/CR, Electrical Safety in the Workplace
16
Shock Hazard Analysis
Shock Hazard Analysis
–
Limited Approach Boundary
Distance from an exposed live part within which a
shock hazard exists
Only Qualified persons and escorted unqualified
persons are allowed within the Limited Approach
Boundary.
–
Restricted Approach Boundary
Distance from an exposed live part within which there
is an increased risk of shock due to electrical arc-over
that may result from inadvertent movement of
personnel working in close proximity to the live part .
FN000385/CR, Electrical Safety in the Workplace
17
Shock Hazard Analysis
Shock Hazard Analysis
–
Prohibited Approach Boundary
Distance from an exposed live part within which work
is considered the same as making contact with the
live part.
FN000385/CR, Electrical Safety in the Workplace
18
Shock Hazard Analysis
FN000385/CR, Electrical Safety in the Workplace
19
Shock Protection Boundaries
Table 130.2(C) Approach Boundaries to Live Parts for Shock Protection. (All dimensions
are distance from live part to employee.)
Exposed Movable
Conductor
Exposed Fixed
Circuit Part
Restricted Approach
Boundary; Includes
Inadvertent Movement
Adder
Not specified
10
0 in.
in.
10 ft
ft 0
10
0 in.
in.
10 ft
ft 0
Not specified
33ftft 6
in.
6 in.
33ftft 6
in.
6 in.
Not specified
Avoid
Avoid contact
contact
11ftft 0
in.
0 in.
Not specified
Avoid
Avoid contact
contact
00ftft 1
in.
1 in.
10
0 in.
in.
10 ft
ft 0
55ftft 0
in.
0 in.
22ftft 2
in.
2 in.
00ftft 7
in.
7 in.
10 ft 0 in.
10 ft 0 in.
6 ft 0 in.
8 ft 0 in.
2 ft 7 in.
2 ft 9 in.
0ft 10 in.
1 ft 5 in.
10 ft 0 in.
10 ft 8 in.
11 ft 0 in.
8 ft 0 in.
8 ft 0 in.
10 ft 0 in.
3 ft 2 in.
3 ft 3 in.
3 ft 7 in.
2 ft 1 in.
2 ft 8 in.
3 ft 1 in.
11 ft 8 in.
13 ft 0 in.
15 ft
ft 4
15
4 in.
in.
11 ft 8 in.
13 ft 0 in.
15 ft
ft 4
15
4 in.
in.
4 ft 0 in.
5 ft 3 in.
88ftft 6 in.
in.
3 ft 6 in.
4 ft 9 in.
88ftft 0 in.
in.
19 ft 0 in.
23 ft 9 in.
19 ft 0 in.
23 ft 9 in.
11 ft 3 in.
14 ft 11 in.
10 ft 9 in.
14 ft 5 in.
Limited Approach Boundary
Nominal System
Voltage Range,
Phase to Phase
Less than 50
50 toto300
300
50
301toto750
750
301
751toto1515kVkV
751
15.1 kV to 36 kV
36.1 kV to 46 kV
46.1 kV to 72.5 kV
72.6 kV to 121 kV
138 kV to 145 kV
161 kV to 169 kV
230 kV to 242 kV
345
362
kV kV
345kV
kVtoto
362
500 kV to 550 kV
765 kV to 800 kV
---------------------------------------------------
Prohibited Approach
Boundary
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.
FN000385/CR, Electrical Safety in the Workplace
20
Shock Protection Boundaries and PPE
Fermilab Summary for NFPA 70E
Shock Protection Boundaries
System Voltage Range
Phase to Phase
50 to 300
Including 120, 277 and 120/208
301 to 750
Including 480/277
751 to 15K
Including 13.8K
345K to 362K
Limited
Approach
Boundary
(Fixed Parts)
Restricted
Approach
Boundary
Prohibited
Approach
Boundary
Shock Protection
Insulating PPE
3 Ft 6 In
Avoid
Contact
Avoid
Contact
LAB - None
RAB - Wear/Use if Contact Likely
PAB - Wear/Use if Contact Likely
1 Inch
LAB - None
RAB - Must Wear
PAB - Must Wear
3 Ft 6 In
1 Foot
5 Feet
2 Ft 2 In
7 Inches
LAB - None
RAB - Must Wear
PAB - Must Wear
15 Ft 4 In
8 Ft 6 In
8 Feet
LAB - None
RAB - Must Wear
PAB - Must Wear
Within the
Limited Approach Boundary
Non-Qualified Worker Allowed Within Only if Advised and Escorted by a QW.
Insulated Equipment/Tools if Contact Likely.
Within the
Restricted Approach Boundary
Only Qualified Worker Allowed Within.
May Not Enter with Conductive Objects.
Body Parts Must be Insulated.
Within the
Prohibited Approach Boundary
Consider Activity as Same as Working On.
FN000385/CR, Electrical Safety in the Workplace
21
Electrically Insulating Gloves
Glove Classes by Use Voltage
Class 00 500 volts
Class 1 7,500 volts
Class 0 1,000 volts
Class 2 17,000 volts
Class 3
Class 4
26,500 volts
36,000 volts
Procure Through Your Local D/S ES&H Department
Gloves must be tested after every 6 months of use
through Fermilab’s program (April 1 and October 1 are
Scheduled Exchange Dates)
Inspect gloves before each use
Use Leather Protectors with Electrically Insulating
Gloves
FN000385/CR, Electrical Safety in the Workplace
22
Arc Flash Hazard Analysis
Determines if thermal hazard exists
–
Identifies required protective equipment
Flash Protection Boundary
–
–
Distance from an exposed live part within which
a person could receive a 2nd degree burn from
an arc-flash
For systems 600 volts or less, the default
boundary is 4 feet
FN000385/CR, Electrical Safety in the Workplace
23
Arc Flash Hazard Analysis
–
For voltages above 600 volts, the Flash
Protection boundary can be calculated with the
general equations
–
Distancecircuit component = [2.65 x MVAbf x t]1/2
–
Distancetransformer = [53 x MVA x t]1/2
MVAbf = bolted fault capacity available at point involved in mega
volt-amps
MVA = capacity rating of transformer in mega volt-amps
FN000385/CR, Electrical Safety in the Workplace
24
Arc Flash Hazard Analysis
Incident Energy Exposure Calculation
–
Requires Single Line Electrical Drawing (SLED)
available fault current
conductor wire sizes
conductor distances
operating voltage of the system
trip time for fuses or circuit breakers
arc fault is in open air or in a box
FN000385/CR, Electrical Safety in the Workplace
25
Table 130.7 (C)(9)(a)
Table
Table 130.7(C)(9)(a)
130.7(C)(9)(a) Hazard/Risk
Hazard/Risk Category
Category Classifications
Classifications
Task
Task (Assumes
(Assumes Equipment
Equipment Is
Is Energized,
Energized, and
and Work
Work
Is
Done
Within
the
Flash
Protection
Boundary)
Is
Done
Within
the
Flash
Protection
Boundary)
Is Done Within the Flash Protection Boundary)
Panelboards
Rated
240
V
—
33 13and 3
Notes
1and
and
Panelboards
Rated
V
and
—
Panelboards
Rated
240240
V and
and
Below
— Notes
Notes
and
Panelboards
Rated
240
V Below
and Below
Below
— 11Notes
Notes
1 and 3
Circuit breaker (CB) or fused switch operation with covers on
Circuit
breaker(CB)
(CB)ororfused
fused
switch
operation
covers
Circuit breaker
switch
operation
withwith
covers
on on
CB
or
fused
switch
operation
with
covers
off
CB or fused switch operation with covers off
Work
Work on
on energized
energized parts,
parts, including
including voltage
voltage testing
testing (LOTO)
(LOTO)
Remove/install CBs or fused switches
Remove/install CBs or fused switches
Removal
Removal of
of bolted
bolted covers
covers (to
(to expose
expose bare,
bare, energized
energized parts)
parts)
Opening hinged covers (to expose bare, energized parts)
Opening hinged covers (to expose bare, energized parts)
Panelboards
or
Switchboards
Rated
>240
and
Panelboards
Switchboards
V and up
Panelboards
or or
Switchboards
RatedRated
>240 V
V>240
and up
up
to 600
600
(with
molded
case
or insulated
insulated
case case
to
600VVV(with
(with
molded
case
or insulated
to
molded
case
or
case
circuit breakers)
breakers)
— Notes
Notes
and
3 3
circuit
—
1 1and
circuit
breakers)
— Notes
1 3and
Circuit breaker
breaker (CB)
(CB) or
or fused
fused switch
switch operation
operation with
with covers
covers on
on
Circuit
CB
or
fused
switch
operation
with covers
covers
offcovers off
CB
switch
operation
with
off
CBor
orfused
fused
switch
operation
with
Work on
on energized
energized parts,
parts, including
including voltage
voltage testing
testing (LOTO)
(LOTO)
Work
Hazard/ Risk
Hazard/
Hazard/ Risk
Category
Category
Category
V-rated
V-rated
V-rated
Gloves
Gloves
Gloves
V-rated
V-rated
V-rated
Tools
Tools
Tools
000
N
N
N
N
N
N
00
1
11
2*
2*
N
N
N
N
N
Y
Y
N
N
N
N
N
Y
Y
00
1
1
1
1
11
0
0
FN000385/CR, Electrical Safety in the Workplace
N
N
Y
Y
Y
Y
N
N
N
N
N
N
Y
Y
Y
Y
N
N
N
N
26
Table 130.7 (C)(9)(a)
Footnotes 1 and 3
–
Footnote #1
25 kA short circuit current available, 0.03
second (2 cycle) fault clearing time.
–
Footnote #3
For < 10 kA short circuit current available, the
hazard/risk category required may be reduced
by one number.
FN000385/CR, Electrical Safety in the Workplace
27
Table 130.7 (C)(9)(a)
Table 130.7(C)(9)(a) Hazard/Risk Category Classifications
Task (Assumes Equipment Is Energized, and Work
Is Done Within the Flash Protection Boundary)
Hazard/ Risk
Category
V-rated
Gloves
V-rated
Tools
CB or fused switch or starter operation with enclosure doors closed
Reading a panel meter while operating a meter switch
0
0
N
N
N
N
CB or fused switch or starter operation with enclosure doors open
Work
parts,
including
voltagevoltage
testing (LOTO)
Workononenergized
energized
parts,
including
testing (LOTO)
1
2*
2*
N
Y
Y
N
Y
Y
Work
Work on
on control
control circuits
circuits with
with energized
energized parts
parts 120
120 V
V or
or below,
below, exposed
exposed
Work
Work on
on control
control circuits
circuits with
with energized
energized parts
parts >120
>120 V,
V, exposed
exposed
00
2*
2*
Y
Y
Y
Y
Y
Y
Y
Y
Insertion
Insertion or
or removal
removal of
of individual
individual starter
starter “buckets”
“buckets” from
from MCC
MCC -- Note
Note 44
Application
Application of
of safety
safety grounds,
grounds, after
after voltage
voltage test
test
33
2*
2*
Y
Y
Y
Y
N
N
N
N
Removal
Removal of
of bolted
bolted covers
covers (to
(to expose
expose bare,
bare, energized
energized parts)
parts)
Opening
hinged
covers
(to
expose
bare,
energized
parts)
Opening hinged covers (to expose bare, energized parts)
2*
2*
11
N
N
N
N
N
N
N
N
600 V Class Motor Control Centers (MCC) Notes 2 (except as indicated) and 3
FN000385/CR, Electrical Safety in the Workplace
28
Simplified Guidance for Electrical Work on Fermilab AC POWER DISTRIBUTION Equipment
Diagnostic Work Including LOTO Voltage Testing Unless Otherwise Noted, Plus Some Additional Operations
Hazard Risk Clasification
Equipment
Voltage
Rated Full
Load
Current
Hazard/Risk
Category
Conditions or Qualifications
Primary Panelboards
SWBD DHP
480/277 VAC
More 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 Centers
MCC
480 VAC
Typical 600
Amps and
Above
2*
Take Advantage of Installed Central Monitoring Unit for LOTO
Verification if Present
Primary or Secondary Panelboards
DHP PHP LP
480/277 VAC
400 to 1,200
Amps
2*
Proximity to Transformer Power Source Presumed
Operating 13.8 KV Disconnects
with Doors Closed
13.8 KV
NA
2
Booster Brentford or RF Anode Power Supplies
are Examples
Secondary Panelboards
PHP LP
480/277 VAC
100 to 225
Amps
1
Assuming Less Than 10,000 ISC Available
More Than 200 Feet from Panelboard Sourcing Power
Lighting Panelboards
LP
480/277 VAC
100 Amps
1
Assuming Less Than 10,000 ISC Available
More Than 100 Feet from Secondary Panelboard Sourcing
Power
Utility Panelboards
Panelboards
Utility
120/208 VAC
120/240 VAC
Below
400
Below 400
Amps
0
No
Above10,000
10,000Amps.
Amps.
NoKnown
KnownFault
Fault Currents
Currents Above
KnowingTransformer
Transformer KVA and
Knowing
and %IZ,
%IZ, Apply
ApplyFormula
Formulaforfor
Suspect Installations
Installations
Suspect
480/277 VAC
NA
0
Requirement Direct from NFPA 70E C9 Table
120/208 VAC
120/240 VAC
NA
-1
No Known Fault Currents Above 10,000 Amps.
Knowing Transformer KVA and %IZ, Apply Formula for
Suspect Installations
Operating Circuit Breakers
and Disconnect Switches
with Covers On or Closed
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.
FN000385/CR, Electrical Safety in the Workplace
29
Simplified Guidance for Electrical Work on Fermilab UTILIZATION Equipment
Hazard Risk Clasification
Diagnostic Work Including LOTO Voltage Testing Unless Otherwise Noted
Equipment
Voltage
Sourcing
Branch CB
Power Supplies
480 VAC
Various
Various Equipment
480 VAC or
480/277 VAC
Various Equipment
Hazard/Risk
Category
Conditions or Qualifications
0 to 3
Ask Your Department for an Assessment.
Take Advantage of Installed Panel Meters for LOTO
Verification.
100 to Less
than 400 Amps
2
Distance from Primary Panelboards and Feed Conductors
Limit Available Fault Currents
480 VAC or
480/277 VAC
Less Than 100
Amps
1
Distance from Primary Panelboards and Feed Conductors
Limit Available Fault Currents
Sump Pump Controllers
Motor Controllers
HVAC Equipment
480 VAC
60 Amps and
Below
1
Distance from Primary Panelboards and Feed Conductors
Limit Available Fault Currents
Ballasts and Light Fixtures
277 VAC
30 Amps and
Below
0
Typical Lighting Ballast
Power Supplies
Supplies
Power
208 VAC
225
and
225 Amps
Amps and
Below
Below
0
NoNo
Known
Above 10,000
10,000 Amps.
Amps. Knowing
Knowing
KnownFault
FaultCurrents
Currents Above
TransformerKVA
KVAand
and %IZ,
%IZ, Apply
Apply Formula
Transformer
Formulafor
forSuspect
Suspect
Installations
Installations
Various Equipment
120/208 VAC
225 Amps and
Below
0
No Known Fault Currents Above 10,000 Amps. Knowing
Transformer KVA and %IZ, Apply Formula for Suspect
Installations
Various Equipment
120 VAC
30 Amps and
Below
-1
Bench Testing.
No Known Fault Currents Above 10,000 Amps.
Can Range from
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 Workplace
30
Arc-Flash Protective Clothing
Hazard Category defines required PPE
NFPA 70E Table 130.7(C)(10)
Fermilab Summary for NFPA 70E Arc-Flash
Hazard/Risk Categories
FN000385/CR, Electrical Safety in the Workplace
31
Table 130.7(C)(10) Protective Clothing and Personal Protective Equipment (PPE) Matrix
Protective Clothing and Equipment
Protective Systems for Hazard/Risk Category
—1
(Note 3)
Arc-Flash Protective Clothing
Hazard/Risk Category Number
0
1
2
3
4
X
X
X
X
(Note 4)
X
(Note 6)
X
X
X
X
X
X
(Note 4)
(Note 5)
X
(Note 6)
(Note 7)
AN
AN
X
(Note 9)
X
(Note 9)
X
(Note 9)
AN
Non-melting (according to ASTM F
1506-00) or Untreated Natural Fiber
a. T-shirt (short-sleeve)
b. Shirt (long-sleeve)
c. Pants (long)
X
X
X
X
FR Clothing (Note 1)
a. Long-sleeve shirt
b. Pants
c. Coverall
d. Jacket, parka, or rainwear
FR Protective Equipment
a. Flash suit jacket (multilayer)
b. Flash suit pants (multilayer)
c. Head protection
1. Hardhat
2. FR hard hat liner
d. Eye protection
1. Safety glasses
2. Safety goggles
e. Face and head area protection
1. Arc-rated face shield, or flash suit hood
AN = As needed
AL = Select one in group
AR = As required FN000385/CR,
X = Minimum required
(Note 5)
AN
X
X
X
X
X
X
-
2. Flash suit hood
3. Hearing protection (ear canal inserts)
f. Hand protection
Leather gloves (Note 2)
g. Foot protection
Leather work shoes
X
-
X
-
AL
AL
-
X
(Note 8)
X
(Note 8)
X
AR
X
AR
AL
AL
AL
AL
X
X
X
X
-
-
AN
X
X
-
AN
X
X
X
Electrical Safety in the Workplace
X
32
Arc-Flash Protective Clothing
Arc-Flash Hazard/Risk Categories - Required Clothing - Required PPE
Fermilab Summary for NFPA 70E
Calculated Exposure
from Prospective Arc-Flash
Hazard/Risk
Category
Minimum
Required
ATPV
Clothing Requirements
Additional PPE
Zero up to 1.2 cal/cm2
-1
NA
Cotton Tee Shirt and Pants
Safety Glasses
2 2
Zeroup
upto
to 1.2
1.2 cal/cm
Zero
cal/cm
00
NA
Long
SleeveCotton
Cotton Shirt
Pants
Long
Sleeve
Shirtand
and
Pants
Safety Glasses
Glasses
Safety
More than 1.2 and up to 4 cal/cm2
1
4 cal/cm2
FR Coverall*
Hard Hat, Safety Glasses
Cotton
Clothing Under
Under FR
Cotton
Clothing
FRCoverall*
Coverall*
Hard
Glasses,
HardHat,
Hat,Safety
Safety Glasses,
Face
Face Shield,
Shield,
Hearing
Protection, Leather
Gloves,
Hearing
Protection,
Leather
Gloves,
Leather Work
Work Shoes
Leather
Shoes
Cotton Clothing Under FR Coverall*
Hard Hat, Safety Glasses,
Double-Layer Switching Hood,
Hearing Protection, Leather Gloves,
Leather Work Shoes
2
Cotton Clothing Under 2 x FR Coveralls*
Hard Hat, Safety Glasses,
Flash Suit Hood,
Hearing Protection, Leather Gloves,
Leather Work Shoes
2
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
2
2
2
2
2*
2
2
More
than44and
and up
More
than
uptoto8 8cal/cm
cal/cm
More than 4 and up to 8 cal/cm
2
More than 8 and up to 25 cal/cm
2
More than 25 and up tp 40 cal/cm
3
4
88cal/cm2
cal/cm2
2
8 cal/cm
25 cal/cm
40 cal/cm
2
* Coverall Rated at 8 cal/cm Available from Fermilab Stockroom
FN000385/CR, Electrical Safety in the Workplace
33
Arc-Flash PPE
All Hazard Risk Categories Require
Eye Protection
Hazard Risk Categories 1 and up require
–
Hard Hats, Leather Gloves, Leather Shoes, and
Fire Resistant rated protective clothing
Hazard Risk Categories 2 and up require
–
Arc-rated face shield or flash suit hood and
Hearing Protection
FN000385/CR, Electrical Safety in the Workplace
34
Fire Resistant (FR) Clothing
Hazard/Risk Category 1 or above, fire
resistant or FR clothing is required
Arc Thermal Protection Value (ATPV)
–
–
Identifies maximum thermal protection the
clothing can provide.
PPE such as face shields, hoods, jackets,
coats, and coveralls have an ATPV rating
Select clothing and equipment that meets or
exceeds minimum ATPV required for the
Hazard/Risk Category
FN000385/CR, Electrical Safety in the Workplace
35
Fire Resistant (FR) Clothing
Wear and care of PPE
–
–
–
–
Wear cotton or natural fiber non melting
clothing
Wear PPE that satisfies the minimum ATPV
required
Layering clothing increases protection
Wear clothing loose rather than tight
Do not use bleach or fabric softeners on
ATPV rated PPE
FN000385/CR, Electrical Safety in the Workplace
36
Electrical Safe Work Condition
Determine all possible power sources
Electrical Hazard Analysis
–
Shock Hazard Analysis
Limited, Restricted, and Prohibited
Approach Boundaries
Shock protection PPE
–
Arc-Flash Hazard Analysis
Hazard Risk Category
Arc-Flash PPE
Flash Protection Boundary
FN000385/CR, Electrical Safety in the Workplace
37
Electrical Safe Work Condition
Plan for Emergencies
–
–
–
–
Know how to de-energize quickly
Be prepared to pull employee free with an
insulated rescue hook
Means available to call 3131
Know CPR and where AED’s are located
Protect unqualified persons from work area
Don the appropriate PPE
FN000385/CR, Electrical Safety in the Workplace
38
Electrical Safe Work Condition
Open disconnect device
Perform LOTO
–
Verification is the most important step
F4 Service Building 13.8 KV Disconnect
switch failure occurred on Wed Oct 1, 2008
FN000385/CR, Electrical Safety in the Workplace
39
Electrical Safe Work Condition
–
Voltage Testing (LOTO)
Use a meter rated for the task
–
–
–
–
Test meter both before and after use when performing
LOTO
Common observation –
People don’t check their meter after performing LOTO
Proximity sensors are not to be used for LOTO
Ground stored energy devices and potential
induced voltage sources
FN000385/CR, Electrical Safety in the Workplace
40
Questions
Resources
–
–
–
–
Fermilab Electrical Safety Subcommittee
Division/Section Senior Safety Officer
Division/Section Electrical Coordinator
Line Management
Fermilab Summary Guidance Sheets
–
http://www-esh.fnal.gov/pls/default/esh_home_page.page?this_page=22152
Enroll in the challenge exam
–
http://www-esh.fnal.gov/pls/default/esh_tests.html
FN000385/CR, Electrical Safety in the Workplace
41