Arc-Flash Hazard
Who is Eaton?:
•Company Overview
•Electrical
•Engineering Services
Arc Flash Overview
What is Arc-Flash?:
•Definitions / Examples
•Dangers
What Can Be Done?:
•Costs
•Engineering Studies & Training
•A.R.M.S.
•Arc-Resistant Gear
•Remote Power Racking
Tom Studer
Eaton Electrical
Power Systems Engineering
Tempe, AZ
© 2003 Eaton Corporation. All rights reserved.
Who is Eaton
• $12.3B 2006 Sales Global Diversified
Industrial Company
• Leader in fluid power systems;
electrical power quality, distribution
and control; automotive engine air
management and fuel economy; and
intelligent drive train systems for fuel
economy and safety in trucks.
Eaton – PSE’s
Power Systems Engineers (PSE’s)
• Average 15 years experience with multiple manufacturers
equipment/devices (GE, Square D, ABB, AB)
• Greater than 30% of PSE’s with Masters in EE
• Licensed Professional Engineers
• Use state of the art Software tools
• Centralized core group – and –
field deployed resources
• Active on standards committees
and recognized industry power
experts
• Headquartered in Cleveland, OH
• Eaton has 60,000 employees and
sells products in more than 129
countries.
• 195 Manufacturing Sites
• Website: www.eatonelectrical .com
• NYSE Ticker: etn
Business Segments
Automotive
Electrical
Fluid Power
Truck
Engineering Studies
ABSTRACT
Power Quality Studies
• Harmonic Analysis
• Transient Analysis
• Effective Grounding
Safety & Reliability Studies
• Power Quality Site Surveys
• Arc Flash Studies & Labeling
• Disturbance Monitoring
• Protective Device Evaluation
.
• Protective Device Coordination
• Power System Investigations
• Grounding
• Short Circuit
• Power System Audit
As more and more industry addresses arc flash electrical safety
concerns, they are discovering high risk associated with what used to
be normal maintenance tasks.
In many cases, the excessively high arc flash incident energies make
it so all maintenance must be done with equipment de-energized -not always acceptable to the process industries.
We will address the multiple ways to significantly lower arc flash
incident energy exposure by new system design and products,
retrofits, retro-fills, equipment modifications, alternate protection
settings, etc.
In most cases, NFPA 70E Hazard Risk Category 2 or lower can be
obtained with the right methods.
Several real world examples will be discussed.
1
Standards Covering Arc Flash
So…
National Fire Protection Agency (NFPA)
NFPA 70-2008 National Electric Code (NEC)
NFPA 70E-2009 Standard for Electrical Safety in the Workplace
.
.
Occupational Safety and Health Administration (OSHA)
OSHA 29 CFR Part 1910
What does each standard have to say about the
Arc Flash Hazard?
Institute of Electrical and Electronics Engineers (IEEE)
C2-2007 National Electric Safety Code (NESC)
1584-2002 Guide for Performing Arc Flash Hazard Calculations
NEC Arc Flash Label
NEC 2008 Edition
Warning Sign
Section 110.16 Flash Protection
.
Electrical equipment, such as switchboards, panelboards,
industrial control panels, meter socket enclosures, and
motor control centers that are in other than dwelling
occupancies and are likely to require examination,
adjustment, servicing, or maintenance while energized
shall be field marked to warn qualified persons of
potential electric arc flash hazards.
The marking shall be located so as to be clearly visible to
qualified persons before examination, adjustment, servicing, or
maintenance of the equipment.
NFPA 70E-2009
NFPA 70E-2009
Article 100. Arc Flash Hazard.
A dangerous condition associated with the
possible release of energy caused by an electric
arc.
130.3 Arc Flash Hazard Analysis
.
FPN No. 1: An arc flash hazard may exist when energized
electrical conductors or circuit parts are exposed or when they
are within equipment in a guarded or enclosed condition,
provided a person is interacting with the equipment in such a
manner that could cause an electric arc. Under normal operating
conditions, enclosed energized equipment that has been properly
installed and maintained is not likely to pose an arc flash hazard.
FPN No. 2: See Table 130.7(C)(9) for examples of activities that
could pose an arc flash hazard.
FPN No. 3: See 130.3 for arc flash hazard analysis information
.
An arc flash hazard analysis shall determine the
Arc Flash Protection Boundary and the personal
protective equipment that people within the arc
Flash Protection Boundary shall use.
2
Arc Flash Hazard Analysis and Labeling
OSHA Code of Federal Regulations
.
IEEE C2-2007 (NESC)
1910.269(l)(6)(ii) – The employer shall train each employee who is
exposed to the hazards of flames or electric arcs in the hazards
involved.
1910.269(l)(6)(iii) – The employer shall ensure that each employee
who is exposed to the hazards of flames or electric arcs does not
wear clothing that, when exposed to flames or electric arcs, could
increase the extent of injury that would be sustained by the
employee.
1910.335(a)(1)(i) – Employees working in areas where there are
potential electrical hazards shall be provided with, and shall use,
electrical protective equipment that is appropriate for the specific
parts of the body to be protected and for the work to be performed.
IEEE 1584-2002
1.1 Scope
Section 41. Supply and communications systems
A.
This guide provides techniques for designers and facility operators to apply in determining the arcflash hazard distance and the incident energy to which employees could be exposed during their
work on or near electrical equipment.
General
1.
.
The employer shall inform each employee working on or about communications equipment or
electric supply equipment and the associated lines, of the safety rules governing the
employee’s conduct while so engaged. When deemed necessary, the employer shall provide
a copy of such rules.
.
1.2 Purpose
2.
The employer shall provide training to all employees who work in the vicinity of exposed
energized facilities. The training shall include applicable work rules required by this Part and
other mandatory referenced standards or rules. The employer shall ensure that each
employee has demonstrated proficiency in required tasks. The employer shall provide
retraining for any employee who, as a result of routine observance of work practices, is not
following work rules.
3.
Effective as of January 1, 2009, the employer shall ensure that an assessment is performed
to determine potential exposure to an electric arc for employees who work on or near
energized parts or equipment. If the assessment determines a potential employee exposure
greater than 2 cal/cm2 exists (see Neal, Bingham, and Doughty [B59]), the employer shall
require employees to wear clothing or a clothing system that has an effective arc rating not
less than the anticipated level of arc energy.
NFPA 70E 2009
NFPA 70E Standard for Electrical Safety in the Workplace 2009
Edition
Arc Flash Hazard-Definition
A dangerous condition associated with the possible release of energy
caused by an electric arc.
FPN No. 1: An arc flash hazard may exist when energized
electrical conductors or circuit parts are exposed or when they are
within equipment in a guarded or enclosed condition, provided a
person is “INTERACTING” with the equipment in such a manner that
could cause an electric arc.
This guide presents methods for the calculation of arc-flash incident energy and arcflash boundaries in three-phase ac systems to which workers may be exposed.
It covers the analysis process from field data collection to final results, presents the
equations needed to find incident energy and the flash-protection boundary, and
discusses software solution alternatives.
Applications cover an empirically derived model including enclosed equipment and
open lines for voltages from 208 V to 15 kV, and a theoretically derived model
applicable for any voltage.
Included with the standard are programs with embedded equations, which may be
used to determine incident energy and the arc-flash-protection boundary.
NFPA 70E 2009
FPN No. 2: See Table 130.7(C)(9) for examples of activities
that could pose an arc flash hazard.
FPN No. 3: See 130.3 for arc flash hazard analysis
information.
Arc Flash Hazard Analysis. A study investigating a worker’s
potential exposure to arc flash energy, conducted for the purpose of
injury prevention and the determination of safe work practices, arc
flash protection boundary, and the appropriate levels of PPE.
Under normal operating conditions, enclosed energized equipment
that has been properly installed and
maintained is not likely to pose an arc flash hazard.
3
What is an Arc-Flash?
An arc flash starts with an
arcing fault. An arcing fault
can be defined as the flow of
current through a path where
it is not intended to flow. The
current creates an electric arc
plasma and releases
dangerous amounts of energy
NFPA 70E CALCS FOR FLASH PROTECTION
BOUNDARY AND INCIDENT ENERGY
Bolted Fault
What is an “arc-fault”?
An electric arc is the passage of
substantial electrical current through
ionized air and gasses.
Bolted
Fault
A B
Arc
Fault
Example:
A B
Short-Circuit Basics
Causes of Bolted Faults
• Re-energizing without
removing temporary
grounds
• Incorrect connection of a
parallel run of cables to a
motor terminal box
Conduit #1
Motor
Conduit #2
NFPA 70E CALCS FOR FLASH PROTECTION
BOUNDARY AND INCIDENT ENERGY
Arcing Fault
NFPA 70E CALCS FOR FLASH PROTECTION
BOUNDARY AND INCIDENT ENERGY
Arcing Fault
• Faults which are not bolted.
• Poor electrical connection between
conductors can cause arcing.
• Arcing results in tremendous heat.
35,0000 F
4
NFPA 70E CALCS FOR FLASH PROTECTION
BOUNDARY AND INCIDENT ENERGY
Arc Flash Introduction
Common Causes of Arcing Faults
Numerous workers injured/killed each year while working
on energized equipment.
Defining incident energy
hazards raises awareness of the harm to humans that
can result from an electric arc. This includes:
• Insulation deterioration and failure
• Work related incidents when working with
tools, removing panels, taking power
measurements, etc.
• Loose connections (cable terminations,
transformer connections, etc.)
DEVELOPMENTS LEADING TO
NFPA 70E-2004
•
Severe skin burns
•
Hearing damage
•
Face and eye injuries
•
Blast pressure injuries
NFPA 70E-2009
NFPA 70E 2009, Table 130.7(C)(10) PPE Requirements
Important Temperatures
HRC
Energy
cal/cm2
Typical Personal Protective Equipment
Skin temperature for curable burn
1760F
0
>0 to 1.2
Non-Melting natural fibers such as 100% cotton (fabric weight at least 4.5 oz/yd2
+ Safety Glasses & Hearing Protection
Skin temperature causing cell death
2050F
1
>1.2 to 4
1 layer Flame Resistant (FR) clothing, min arc rating of 4 cal/cm 2
+ Hard hat, safety glasses, Hearing Prot., Faceshield & Hand Prot.
Ignition of clothing
2
>4 to 8
1 layer FR clothing, min arc rating of 8 cal/cm2
+ Hard hat, safety glasses, Face shield, Hearing Prot., Hand Prot. & Foot Prot.
(cotton T-shirt is optional, not required)
Burning clothing
14720F
3
>8 to 25
Multilayer of FR clothing, min Arc rating of 25 cal/cm2
+ Flash suit hood, safety glasses, hearing protection, hand & foot protection
(cotton T-shirt is optional, not required)
Metal droplets from arcing
18320F
4
>25 to 40
Multilayer of FR clothing, min Arc rating of 40 cal/cm2
+ Flash suit hood, safety glasses, hearing protection, hand & foot protection
(cotton T-shirt is optional, not required)
Surface of sun
90000F
Arc terminals
7520F-14720F
35,0000F
NFPA 70E Protective Clothing and
PPE Table (Table 130.7(C)(10)©NFPA)
Hazard/Risk Category
Protective Clothing and PPE
Hazard/Risk Category 0
•
•
•
•
Undergarments: Must be non meltable fibers such as 100% cotton
FR clothing: Shirt and pants. Alternative is coveralls
Hand Protection: Leather gloves or Leather protectors over Rubber gloves
Foot Protection: Leather Work shoes or boots
NFPA 70E Protective Clothing and
PPE Table (Table 130.7(C)(10)©NFPA)
Hazard/Risk Category
Protective Clothing and PPE
Hazard/Risk Category 2
- Protective Clothing ,Non-melting (According to
ASTM F 1506-00) or Untreated Natural Fiber
Shirt (long sleeve)
Pants (long
- FR Protective Equipment
Safety glasses or safety goggles (SR)
Hearing protection (ear canal inserts)
Leather gloves (AN) (Note 2)
Hazard/Risk Category 1
- FR Clothing ,Minimum Arc Rating of 4 (Note 1)
Arc-rated long-sleeve shirt (Note 3)
Arc-rated pants (Note 3)
Arc-rated coverall (Note 4)
Arc-rated face shield or arc flash suit hood (Note 7)
Arc-rated jacket, parka, or rainwear (AN)
- FR Protective Equipment
Hard hat
Safety glasses or safety goggles (SR)
Hearing protection (ear canal inserts)
Leather gloves (AN) (Note 2)
Leather work shoes (AN)
- FR Clothing ,Minimum Arc Rating of 8 (Note 1)
Arc-rated long-sleeve shirt (Note 5)
Arc-rated pants (Note 5)
Arc-rated coverall (Note 6)
Arc-rated face shield or arc flash suit hood (Note 7)
Arc-rated jacket, parka, or rainwear (AN)
- FR Protective Equipment
Hard hat
Safety glasses or safety goggles (SR)
Hearing protection (ear canal inserts)
Leather gloves (AN) (Note 2)
Leather work shoes (AN)
Hazard/Risk Category 2*
- FR Clothing ,Minimum Arc Rating of 8 (Note 1)
Arc-rated long-sleeve shirt (Note 5)
Arc-rated pants (Note 5)
Arc-rated coverall (Note 6)
Arc-rated arc flash suit hood (Note 10)
Arc-rated jacket, parka, or rainwear (AN)
- FR Protective Equipment
Hard hat
Safety glasses or safety goggles (SR)
Hearing protection (ear canal inserts)
Leather gloves (AN) (Note 2)
Leather work shoes (AN)
5
NFPA 70E Protective Clothing and
PPE Table (Table 130.7(C)(10)©NFPA)
Hazard/Risk Category
Protective Clothing and PPE
Hazard/Risk Category 3
NFPA 70E Protective Clothing and
PPE Table (Table 130.7(C)(10)©NFPA)
Hazard/Risk Category
Protective Clothing and PPE
Hazard/Risk Category 4
- FR Clothing ,Minimum Arc Rating of 25 (Note 1)
Arc-rated long-sleeve shirt (AR) (Note 8)
Arc-rated pants (AR) (Note 8)
Arc-rated coverall (AR) (Note 8)
Arc-rated arc flash suit jacket (AR) (Note 8)
Arc-rated arc flash suit pants (AR) (Note 8)
Arc-rated arc flash suit hood (Note 8)
Arc-rated jacket, parka, or rainwear (AN)
- FR Clothing ,Minimum Arc Rating of 40 (Note 1)
Arc-rated long-sleeve shirt (AR) (Note 9)
Arc-rated pants (AR) (Note 9)
Arc-rated coverall (AR) (Note 9)
Arc-rated arc flash suit jacket (AR) (Note 9)
Arc-rated arc flash suit pants (AR) (Note 9)
Arc-rated arc flash suit hood (Note 9)
Arc-rated jacket, parka, or rainwear (AN)
- FR Protective Equipment
Hard hat
FR Hard Hat Liner (AR)
Safety glasses or safety goggles (SR)
Hearing protection (ear canal inserts)
Leather gloves (Note 2)
Leather work shoes
- FR Protective Equipment
Hard hat
FR Hard Hat Liner (AR)
Safety glasses or safety goggles (SR)
Hearing protection (ear canal inserts)
Leather gloves (Note 2)
Leather work shoes
NFPA 70E Protective Clothing and
PPE Table (Table 130.7(C)(10)©NFPA)
Why is an Arc Hazardous?
AN = As needed (optional)
AR = As required
SR = Selection Required
Notes:
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
See Table 130.7(C)(11). Arc Rating for a garment or system of garments is express in cal/cm2.
If rubber insulating gloves with leather protectors are required by Table 130.7(C)(9), additional leather or
arc-rated gloves are not required. The combination of rubber insulating gloves with leather protectors
satisfies the arc flash protection requirement.
The FR shirt and pants used for Hazard/Risk Category 1 shall have a minimum arc rating of 4.
Alternate is to use FR coveralls (minimum arc rating of 4) instead of FR shirt and FR pants.
The FR shirt and pants used for Hazard/Risk Category 2 shall have a minimum arc rating of 8.
Alternate is to use FR coveralls (minimum arc rating of 8) instead of FR shirt and FR pants.
A face shield with a minimum arc rating of 4 for Hazard/Risk Category 1 or a minimum arc rating of 8 for
Hazard/Risk Category 2, with wrap-around guarding to protect not only the face, but also the forehead,
ears, and neck (or alternatively, an arc-rated flash suite hood), is required.
An alternate is to use a total FR clothing system and hood, which shall have a minimum arc rating of 25 for
Hazard/Risk Category 3.
The total clothing system consisting of FR shirt and pants and/or FR coveralls and/or arc flash coat and
pants and hood shall have a minimum arc rating of 40 for Hazard/Risk Category 4.
Alternate is to use a face shield with a minimum arc rating of 8 and a balaclava (sock hood) with a
minimum arc rating of 8 and which covers the face, head and neck except for the eye and nose areas.
35,000 °F
Molten Metal
Pressure Waves
Sound Waves
Shrapnel
Copper Vapor:
Solid to Vapor
Expands by
67,000 times
Hot Air-Rapid Expansion
Intense Light
Courtesy of Cooper Bussmann
Bad things can happen.
An electric arc fault is a bad thing!
Bad things can happen.
An electric arc fault is a bad thing!
6
Bad things can happen.
An electric arc fault is a bad thing!
Bad things can happen.
An electric arc fault is a bad thing!
•Large Hydro in
Pacific NW
•6.9kV Swgr
•Racking in
Breaker
•AF occurred
•One worker
injured
•7+ years, $10+
million
Bad things can happen.
An electric arc fault is a bad thing!
Bad things can happen.
An electric arc fault is a bad thing!
Bad things can happen.
An electric arc fault is a bad thing!
Bad things can happen.
An electric arc fault is a bad thing!
7
Arc Flash Injuries
Arc Blast Pressure
165 db
Arc Blast Pressure
The pressure from an electric arc is developed
from two sources:
< 740 mph
IR
Visible
27,000°F
50
cal/cm2
UV
1830 °C
2000 psf
Arc Blast Pressure Example
Expansion of the metal as it vaporizes
Heating of air by the arc energy
When copper vaporizes, it expands by a factor of
67,000. This accounts for the expulsion of nearvaporized droplets of molten metal from the arc
(droplets could be propelled up to 10 feet).
Inhalation Injuries
Inhalation Injuries
In addition to burns, an arc flash can cause
inhalation injuries.
More than a hundred known toxic substances
are present in fire smoke.
When inhalation injuries are combined with
external burns the chance of death can increase
significantly.
Failed 50kA 5kV available fault current 0.5sec – FULL SPEED
Toxic Smoke Example
DEVELOPMENTS LEADING TO NFPA
70E-2004
Burn Injuries
Burns are classified as first, second, or third
degree, depending on how deeply the layers of
skin (dermis and epidermis) are damaged.
8
DEVELOPMENTS LEADING TO NFPA
70E-2004
DEVELOPMENTS LEADING TO NFPA
70E-2004
Diagram of Normal Skin
Epidermis
A First Degree Burn is red and sensitive to
touch. There is minimal skin damage and
only the skin surface is involved.
Dermis
Example: Sunburn
Hypodermis or subcutaneous tissue
Muscle
DEVELOPMENTS LEADING TO NFPA
70E-2004
A Second Degree Burn involves the first
and second layers of skin. The skin
reddens intensely and blisters develop.
Severe pain and swelling occur and chance
for infection is present.
DEVELOPMENTS LEADING TO NFPA
70E-2004
What Is a Calorie?
A calorie is the energy required to raise
one gram of water one degree Celsius at
one atmosphere.
DEVELOPMENTS LEADING TO NFPA
70E-2004
A Third Degree Burn causes charring of
skin and coagulation of blood vessels just
below the skin surface. All three layers of
skin are affected.
Extensive scarring
usually results.
DEVELOPMENTS LEADING TO NFPA
70E-2004
The intent of NFPA 70E regarding arc flash is
to provide guidelines which will limit injury to
the onset of second degree burns.
At 1 second, 1.2 cal/cm2 of heat energy
can cause a second degree burn.
9
DEVELOPMENTS LEADING TO
NFPA 70E-2004
DEVELOPMENTS LEADING TO
NFPA 70E-2004
Definition of Incident Energy
The intent of NFPA 70E regarding arc flash is to
provide guidelines which will limit injury to the
onset of second degree burns.
Three Main Factors Affecting
Incident Energy and Arc Flash
Skin damage will occur based on the intensity of the
heat generated by an electrical arc accident. The heat
reaching the skin of the worker is dependent on the
following three factors:
Main Factors Affecting Arc Flash:
IEEE defines incident energy as the amount of
energy impressed on a surface, a certain
distance from the source, generated during an
electrical arc event.
Incident energy is measured in calories/cm2 or in
Joules/cm2.
DEVELOPMENTS LEADING TO
NFPA 70E-2004
The following table shows how the power of
the arc and/or time duration of the arc will
affect incident energy when the worker
distance is held constant at 18 inches from the
arc flash.
Note: The incident energy
calculations were performed using the “Arc in
a Box” equations.
• Power of the arc at the arc location
• Distance of the worker to the arc
• Time duration of the arc exposure
Illustration of Power and Time Effects on
NFPA Calculations for Arc in a Box
Hold Distance
Constant
Holdtime
SC
••Hold
currentat 3
constant
constant
cyclesat 30
kA
• Vary the SC
• Vary from
the
current
time
3 to
16kAfrom
to 50kA
60 cycles
• Relatively
• Significant
small
change
change
in
terms in
of
terms of
required
PPE
required
(~
2 cal toPPE
~9
(~ 3 cal)
cal to ~
60 cal)
Distance
18
18
18
18
18
18
18
18
(inches)
Clearing
3
6
10
20
30
40
50
60
Time (cyc)
(sec)
0.05
0.10
0.17
0.33
0.50
0.67
0.83
1.00
SC kA
cal/cm2 cal/cm2 cal/cm2 cal/cm2 cal/cm2 cal/cm2 cal/cm2 cal/cm2
16
2.07
4.14
6.90
13.81
20.71
27.62
34.52
41.42
18
2.03
4.06
6.76
13.52
20.29
27.05
33.81
40.57
20
2.04
4.08
6.80
13.60
20.40
27.21
34.01
40.81
22
2.11
4.21
7.02
14.05
21.07
28.09
35.11
42.14
24
2.23
4.46
7.43
14.85
22.28
29.71
37.13
44.56
26
2.40
4.81
8.01
16.02
24.04
32.05
40.06
48.07
28
2.63
5.27
8.78
17.56
26.34
35.12
43.90
52.67
30
2.92
5.84
9.73
19.46
29.18
38.91
48.64
58.37
32
3.26
6.52
10.86
21.72
32.58
43.44
54.30
65.16
34
3.65
7.30
12.17
24.35
36.52
48.69
60.86
73.04
36
4.10
8.20
13.67
27.34
41.00
54.67
68.34
82.01
38
4.60
9.21
15.34
30.69
46.03
61.38
76.72
92.07
40
5.16
10.32
17.20
34.41
51.61
68.81
86.02 103.22
42
5.77
11.55
19.24
38.49
57.73
76.98
96.22 115.46
44
6.44
12.88
21.47
42.93
64.40
85.87 107.33 128.80
46
7.16
14.32
23.87
47.74
71.61
95.49 119.36 143.23
48
7.94
15.87
26.46
52.92
79.37 105.83 132.29 158.75
50
8.77
17.54
29.23
58.45
87.68 116.91 146.13 175.36
NFPA 70E CALCS FOR FLASH PROTECTION
BOUNDARY AND INCIDENT ENERGY
Calculating Prospective Short-Circuit Current, ISC
NFPA 70E-2004, Annex D.3©NFPA provides the “well known”
formula that is used to calculate the short-circuit symmetrical
amperes from a bolted 3-phase fault at a transformer
terminals:
I SC =
MVABase × 10 6 100
×
1.732 × V
%Z
(4 - 1)
10
NFPA 70E CALCS FOR FLASH PROTECTION
BOUNDARY AND INCIDENT ENERGY
Arc-Flash Costs: Human
Classroom Exercise 4a: Perform a Calculation of
Prospective Short Circuit Current
Problem: Using equation (4-1), calculate the prospective
short circuit current for a fault at the 480 V terminals of a
1500 kVA transformer which has a nameplate impedance
of 5.5%.
I SC
1.5 ×106
100
×
=
1.732 × 480 5.5
= 32,805 Amps
PPE – Too Much
Employee performed some troubleshooting on 15KV Gear and
determined that he did not have control power
Customer was instructed to restore power to the 15KV B side main
breaker and remove power from the A side main breaker
Employee locked out the A side main breaker and the tie breaker
Employee pulled the CPT drawer on the A side main on the front of
the switchgear and adjusted the secondary contacts
Employee visually inspected the routing of the 15 kV power cables
on the A side CPT connections in the rear of the switchgear
Customer was instructed to restore power to the A side main and the
employee verified the control power was still not present
Clothed areas can
be burned more
severely than
exposed skin.
The most severe
burns are caused
by ignited clothing,
not by the original
flash fire or electric
arc exposure.
PPE – Not Enough
Nor this
Not this
Accident Description
Accident Description Continued
Employee crawled into the lower compartment of vertical section 6
Employee opened the shutter in the VT compartment to see if the 15
kV jumper cables were installed and connected between the CPT
and VT drawers
When Employees flashlight got too close to the ionized air, there was
an arc flash incident
11
Arc Flash Incident
Arc Flash Incident
Arc Flash Incident
Arc Flash Incident
Arc Flash Incident
Arc Flash Incident
12
Injury Consequences
Burn injuries can be fatal.
Survival depends on age, health, exposure
intensity and time, area of the body burned.
Treatment of second degree burns requires
weeks, for third degree burns it can be
years.
Arc-Flash Costs: Monetary
National Institute for Occupational Safety
and Health (NIOSH)
from the US Bureau of Labor Statistics
Arc Flash Example
Failed 50kA 5kV available fault current 0.5sec – FULL SPEED
The Personal Cost Is Devastating
Due to disfigurement and intense pain the
victim will often not want to live,
depression is common.
Children will likely not be able recognize
the burn victim after the accident.
The victim’s spouse will be traumatized,
divorce is common.
Treating Burn Injury Is Very Expensive
The cost of treatment can exceed $1,000,000
USD for a single case.
Treatment can require years of skin grafting
and rehabilitation.
The victim may never be able to return to
work.
Arc Flash Example
Failed 50kA 5kV available fault current 0.5sec – SLOW MOTION
13
Arc Flash Standards
and OSHA Six-Point Plan
NIOSH Data for the year 2000
Four separate industry standards concern the prevention of arc flash incidents:
OSHA 29 Code of Federal Regulations (CFR) Part 1910 Subpart S.
NFPA 70-2008 National Electrical Code.
IEEE Standard 1584-2002 Guide for Performing Arc Flash Hazard Calculations.
NFPA 70E-2009 Standard for Electrical Safety in the Workplace.
Nonfatal injuries and illnesses = 5.7 million
Days away cases = 1.7 million
Fatal work related injuries = 5,920
Compliance with the latest OSHA standards involves adherence to a six-point plan:
A facility must provide, and be able to demonstrate a safety
program with defined responsibilities.
Calculations for the degree of arc flash hazard.
Correct personal protective equipment (PPE) for workers. (FR Rated Clothes, HV Gloves, Face Shield)
Training for workers on the hazards of arc flash.
Appropriate tools for safe working. (Grounds, rubber mats, voltage detectors, hot sticks etc.)
Warning labels on equipment. (Arc Flash Labels with Incident Energy (cals) & appropriate PPE)
Companies will be cited and fined for not complying with these
standards.
NIOSH Electrical fatalities by industry,
1992-2000.
Days away electrical cases = 3,786
Electrical Fatalities = 260
About 1 of every 450 nonfatal accidents involved
electricity, but….
1 of every 23 deaths was caused by electricity.
Nonfatal electrical shock and burn
injuries involving days away from work
1992-2000 by industry
NIOSH’s summary & conclusions from
these statistics:
Electrical accidents are more likely to result in death than many
other types of accidents.
Contact with overhead power lines is the leading cause of onthe-job electrical death.
The construction industry accounted for 45% of electrical
deaths followed by: Agriculture (12%); Transportation (11%);
Manufacturing (11%); Service (10%).
Nonfatal electrical accidents are:
distributed more evenly across all industries than are
fatalities, but construction industry is still highest.
Electrical shock and electrical burns and their
distribution varies widely by industry.
Arc Flash History Timeline
1968 Dow implements arc flash PPE program
1980 Published article on use of arc flash PPE
1981 Ralph Lee publishes theory for hazard
calculations
1986 DuPont implements arc flash PPE program
1990 OSHA subpart S does not address arc flash
details
1994 OSHA 1910.269 addresses clothing hazards
1995 DuPont undertakes arc flash R&D
1995 ASTM Arc Test Method development
14
ARC FLASH Avoidance:
Arc Flash History Timeline
Superior Protection with the Right Products
What Can Be Done:
1995 NFPA70E defines arc flash boundary
1996 DuPont arc flash research published
Engineering Studies:
1997 DuPont protective clothing research published
Arc Flash Study!...(includes Arc Flash Labels)
1998 ASTM standards for PPE testing
Protective Device Coordination (Breaker Settings)
Short Circuit Study
1999 Arc Flash rated PPE appears
2000 NFPA70E expands arc flash requirements
2002 NEC requires arc flash hazard warning
2002 IEEE 1584 calculation guide published
2004 NFPA 70E major reorganization
Training
Personal Protective Equipment
Arc Flash Reduction Maintenance Switch
Arc-Resistant Switchgear & Controls
Remote Power Racking
STANDARDS
EESS NFPA70E Arc Flash Compliance
NFPA 70E (2009)
Key Features
Asset Optimization
Knowledge Management
Eaton Engineering Services &
Systems Arc Flash Studies
Integrated Project Solutions
Equipment shall be field marked with a label containing the available
incident energy or required level of PPE. (130.4(C))
Power Systems Engineering
Solutions
Power Systems Modernization
Arc Flash Hazard Analysis shall be updated when a major modification or
renovation takes place. (130.3)
New Equipment Services
Field Services
70+ Power Systems
Engineers
Standardized Data
Collection Templates
Studies, Labels, Training,
Recommendations
Arc Flash Hazard Analysis shall be reviewed periodically, not to exceed 5
years. (130.3)
Hazard Risk Categories (0-4). Changes in PPE; Level 1 PPE includes face
shield. (130.7(C)(10))
NFPA 70-2005 (NEC)
E-ESS ARC FLASH PROGRAM
Warning Sign
A calorie is the energy required to raise one
gram of water one degree Celsius at one
atmosphere.
At 1 second duration, 1.2 cal/cm2 of incident
heat energy can cause a second degree burn.
E-ESS PROTECTIVE CLOTHING AND
PERSONAL PROTECTIVE EQUIPMENT MATRIX
Protective Clothing
& Equipment
NFPA 70E Hazard/Risk
Category Number
Range of Arc Rating (cal/cm2)
FR Clothing
Coveralls (1 layer)
Minimum Arc Rating = 8 cal/cm2
Two Coveralls (2 layer)
worn over
Minimum Arc Rating (for 2 layers)
= 40 cal/cm2
Jacket, parka, or rainwear
Protective Systems for Hazard/Risk Category
0
1
2
3
4
> 0 to 1.2
1.2 to 4
4 to 8
8 to 25
25 to 40
X
X
X
AN
AN
X
X
AN
AN
15
Arc Flash Hazard Analysis and Labeling
NFPA 70E 2009 Annex H
Simplified two Category FR Clothing
Categories 0,1 & 2:
8+ Calorie FR long-sleeve shirt
8+ Calorie FR Pants
Arc Flash Hazard Analysis and Labeling
Eaton Recent Arc Flash Study’s
Categories 3 & 4
40+ Cal Jacket
40+ Cal Pants
40+ Cal Hood
Gloves, Faceshield/Hood, Hearing Protection
Leather Shoes, Safety Glasses, (per hazard level)
Eaton Local Arc Flash Study’s
Asarco Copper Mines
Sky Harbor Airport
USAA Insurance Group
TEP Springerville
Wild Horse Pass Casino
Chase Field
Cargill
179 Sites
Georgia Pacific
54 Sites
VA Hospitals
25 Sites
Enbridge Pipeline
25 Sites
Weyerhaeuser
104 Sites
Woodbridge Group 14 Sites
GM
12 Sites
Ford
10 Sites
Arc Flash Incident
16
Arc Flash Incident
Arc Flash Incident
Arc Flash Incident
Training
Understanding Arc-Flash
•Existing and Proposed Standards
•Determining Safe Approach Distance
•Methods for Calculating Prospective Short Circuit Current
•IEEE Standard 1584 & NFPA 70E Methods for Calculating
Flash Protection Boundary Distance and Incident Energy
Value
Training
Understanding Arc-Flash
•Determining Hazard Risk Category
•Selecting Protective Clothing and
the PPE Matrix
Flash Protection Boundary And
Limits Of Approach
•ATPV Values for Common Types
of Garments
•Practical Methods for Reducing
Arc-Flash Hazard
•Eaton can award 0.8 CEUs for the successful completion of this
training.
17
FLASH PROTECTION BOUNDARY
AND LIMITS OF APPROACH
Approach / Flash Protection Boundaries
Definitions of Boundaries and Spaces
The closer you approach an exposed, energized
conductor or circuit part, the greater the chance
of an inadvertent contact and the greater the
injury that an arc flash will cause. NFPA 70E2004, Annex C©NFPA defines approach
boundaries and work spaces. The diagram on
the next slide illustrates these.
FLASH PROTECTION BOUNDARY
AND LIMITS OF APPROACH
FLASH PROTECTION BOUNDARY
AND LIMITS OF APPROACH
NFPA 70E-2004, Table 130.2(C)NFPA
Approach Boundaries to Live Parts for Shock Protection.

(All dimensions are distance from live part to employee.)
(1)
(2)
(3)
(4)
(5)
Qualified Person (OSHA 29CFR1910) (Cont.)
1
Limited Approach Boundary
Restricted Approach
1
Boundary ; Includes
Inadvertent Movement
Adder
Nominal System
Voltage Range,
Phase to Phase
Exposed
Movable
Conductor
Exposed
Fixed Circuit
Part
Prohibited
Approach
Boundary1
< 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.
0 ft 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.
Know what precautions to take to work safely,
including:
•
how to carry out lockout/tagout procedures
•
how to manage and maintain a safe work area
•
how to use protective grounds
Know how to use PPE
Know how to use insulating and shielding materials
Know how to use insulated tools
2 ft 1 in.
1. See definitions in NFPA 70E-2004 Article 100, and text in NFPA 70E-2004 130.2 (D)(2) and Annex C for
elaboration.
FLASH PROTECTION BOUNDARY
AND LIMITS OF APPROACH
Qualified Person (OSHA 29CFR1910) (Cont.)
Note: A qualified person must be certified by his
employer before working on or near energized
equipment, (1910.269a2vii) and must have his or
her qualifications reviewed annually.
(1910.269a2iii)
FLASH PROTECTION BOUNDARY
AND LIMITS OF APPROACH
Work intentionally performed on or near
energized equipment or circuits is limited by
standards and regulations, such as those issued
by OSHA.
Only qualified persons may work on energized electric
circuits. (1910.333c2)
Only qualified persons may perform tests on electric
circuits or equipment. (1910.334c1)
Only qualified persons may work on or with exposed
lines or parts of equipment. (1910.269l1)
18
FLASH PROTECTION BOUNDARY
AND LIMITS OF APPROACH
Only qualified persons may work in areas containing
unguarded, uninsulated energized lines or parts of
equipment operating at 50 volts or more. (1910.269l1)
Live parts to which an employee may be exposed
shall be de-energized before the employee works on
or near them, unless the employer can demonstrate
that de-energizing introduces additional or increased
hazards or is infeasible due to equipment design or
operational limitations. (1910.333)
SOLUTIONS THAT REDUCE ARC FLASH
INJURIES and DAMAGE
Label Equipment & Train Personnel
Minimize Risk with Good Safety Practices
Reduce Available Fault Current
Faster Clearing Time
Move People Further Away
Redirect Blast Energy
Prevent Fault
PRACTICAL METHODS FOR
REDUCING ARC FLASH HAZARDS
Minimize Risk with Good Safety Practices
De-Energize Equipment versus “Working It Live”
unless increased hazards exist or infeasible due to
design or operational limitations.
Switching remotely (if possible)
Closing and tightening door latches or door bolts
before operating a switch.
Standing to the side and away as much as possible
during switching operations.
PRACTICAL METHODS FOR
REDUCING ARC FLASH HAZARDS
Minimize Risk with Good Safety Practices
- if you can maintain fast clearing times
Practical Methods for Reducing Arc Flash Hazards
Minimize Risk with Good Safety Practices
PRACTICAL METHODS FOR
REDUCING ARC FLASH HAZARDS
Minimize Risk with Good Safety Practices
Using the proper tools and equipment (Line side of Main).
Bad – Exposed Back of Neck
Good – All of Body Protected
19
PRACTICAL METHODS FOR
REDUCING ARC FLASH HAZARDS
PRACTICAL METHODS FOR
REDUCING ARC FLASH HAZARDS
Minimize Risk with Good Safety Practices
Equipment Alternatives
Using the proper tools and equipment (Load side of Main).
Current-Limiting Breakers / Fuses - Reduces the
clearing time which reduces the incident energy.
Metal-Clad Switchgear - Structural design reduces the
possibility of arcing faults within the enclosure.
Arc Resistant Switchgear - Structural design includes
robust design and pressure relief vents, which redirect the blast away from the worker.
ARC FLASH Avoidance:
ARC FLASH Avoidance:
Superior Protection with the Right Products
Superior Protection with the Right Products
What is PPE?
What is PPE?
Personal Protective Equipment
It is worn by everyone. Police
officers, professional athletes,
construction workers, chefs and
everyone in between.
Hard Hat with
Arc Face Shield
Rubber Gloves
31 Cal. Arc Suit & Hood
F/R Coveralls
Electrical PPE
ARC FLASH Avoidance:
ARC FLASH Avoidance:
Superior Protection with the Right Products
Superior Protection with the Right Products
ARMsTM* – Retrofit for
Low Voltage Circuit Breakers
Arc-flash Reduction Maintenance Switch (ARMS)
•Used to reduce the trip
delay of LV circuit breakers
while performing
maintenance.
•Enabled with the circuit
breaker door closed by a
door mounted lockable
switch
•Preserves coordination
under normal conditions (not
enabled continuously)
Door Mounted Components
Breaker Mounted
Components
DIGITRIP
Harness
Lockout
Switch
Battery
*Arcflash Reduction Maintenance Switch
20
Practical Methods for Reducing Arc Flash
Hazards
Medium Voltage ARMS
FP--5000 – Group Settings
Using FP
Multiple Settings Groups
• Similar to LV maintenance
switch, only for MV applications
FP-5000 Relay
• Used to reduce the trip delay of
medium-voltage relays while
maintenance is being performed on
equipment
Indicating Light
• Requires relay with multiple
settings groups capability, such as
the Cutler-Hammer FP-5000
Switch
Reduce Clearing Time
FlashGard® MCC
Network Protectors
The Ultimate Arc Fault preventive solution
ARC FLASH Avoidance:
FlashGard®
FlashGard® Motor Control Center
Superior Protection with the Right Products
The FlashGardTM Bucket
Racking Tool Receiver
Bucket Position
Unit Latch
Internal Shutter Position
Features
Open
Closed
Connected
Test
Withdrawn
Handle Mechanism
Device Island
• Start, Stop, Auto, Man
Breaker
Starter
Specially designed Stab Assembly
• Designed to fit tightly with the labyrinth
vertical bus bar making it virtually arc free
480 Volt Isolation via stab shutter
Extendable and Retractable power stabs – up to
400 Amp Stab
• Allows you to engage or disengage the stab
with the vertical bus while the door is closed
keeping you at a safe distance while
performing this operation
RotoTractTM assembly – No over torque
• Special screw design spins free at the end of
travel in either direction preventing over
torque of the mechanism
Status Indication
• Stab position indication
• Stab shutter position indication
21
FlashGard ® Door Accessories
Remote Racking “wired” Accessory
Accessory to perform RotoTract
racking safely behind NFPA Arc Flash
boundaries
ARC FLASH Avoidance:
Superior Protection with the Right Products
How it works
Bucket Position
Indicator
Internal Shutter
Indicator
Connected
120 VAC motor driven
Open
Test
Mounts to RotoTract Mechanism
Closed
Withdrawn
Wired pendant station for “rack-in”/
“rack-out” operation.
Momentary Jog
Mounting offset bracket to clear device
panel
ARC FLASH Avoidance:
Superior Protection with the Right Products
Overrunning mechanism
prevents stripping of
the mechanism or
overtorquing
Breaker must be
open to access
racking tool
receiver
Makes insertion of large
size 4,5 buckets a
much safer evolution.
No more shoving
buckets on to the
vertical bus.
APPLICATIONS
Fiber Optic Arc Mitigation Devices
Electrical Incidents
Motor Control Centers account for the second highest
frequency of electrical accidents. As a result of this finding, the
industry is in need of a Motor Control Center that addresses all
of these potential hazards.
MCC’s
Fiber Optic Arc Mitigation
Devices
APPLICATIONS
Fiber Optic Arc Mitigation Devices
UL Listing Issues
NO INDUSTRY STANDARD exists for the design,
application, or performance for these systems.
On January 27, 2010, Underwriters Laboratories
held a meeting to address this issue. UL clearly
stated in the January meeting that they do NOT
recognize any arc flash detection (light detection)
systems.
Able to Distinguish Between Light
from Fault and Background
Lighting
Fast Acting Relay Trips Breaker
Instantaneously
European Design (Vaasa, ABB,
Etc.)
SEL, iGard & Eaton
APPLICATIONS
Fiber Optic Arc Mitigation Devices
UL Listing Issues
Eaton and UL are fully aware that several suppliers of devices
that sense internal arcs and operate upstream protective
devices have obtained UL labels. These labels, however,
have been obtained utilizing generic standards intended for
other types of devices, such as protective relays. In essence,
they are misleading users relative to the certified capabilities
of these devices.
Customers need to be aware, that should UL labeled
equipment integrated with these devices become involved in
accidents that result in damage or injury, the suppliers of
these devices will not have a legitimate industry standard
upon which to claim safety compliance.
22
APPLICATIONS
Fiber Optic Arc Mitigation Devices
Other Issues with these Devices
Eaton will not utilize these devices to reduce PPE
Requirement calculated in an Arc Flash Study. No
test standard to justify engineering calculation for
arc flash study.
Infrared Scanning
Windows for LV/MV
Assemblies
Other arc mitigation devices like GE Arc Vault also
would have UL issue.
Can install in Non-Listed Assemblies
May be utilized as a “back-up” system.
Remote Switching: Chicken Switch
Safety Related Solution Offerings
Without
Remote Racking of MV Breakers VCP-W 5/15 kV Swgr – New Swgr
With
Remain physically outside the flash protection boundary.
Therefore NO ARC FLASH HAZARD protection required!
Increase Working Distance
Increase Working Distance
ARC FLASH Avoidance:
ARC FLASH Avoidance:
Superior Protection with the Right Products
Remote Racking
Superior Protection with the Right Products
Remote Racking – Eaton’s
Universal Design for Retrofit Applications
• LV or MV
VS
• Any breaker
o Air-Magnetic
o Vacuum
o Vacuum Replacement
o SF6
• 1-2 high MV & 1- 4 high LV
• Flashgard MCC
23
AmpGard Motor Operated Iso
Switch
Motor Operated Iso Switch
New Optional Accessory
For Remote Operation Of
Ampgard Isolation
Switch And Increased
Operator Safety.
Temporarily Mounts To
Front Of Starter Door
Equipped With Mounting
Provisions.
Operation By Control
Station Connected To
Motor Operator Via 25foot Cable.
ArcArc-Resistant Switchgear
5/15 kV Arc Construction
Arc Flaps
Redirects Arc Energy and Particulates
Control
Section
2000A or
3000A breaker
with Vent
VT
drawer
LV Arc Resistant Switchgear - Testing
1200A can be 1
high or 2 high
Manual Close/Open
Push Buttons
Substations Without Main Secondaries
AFL Retrofit
Test @ 65kA / 508V
Arc initiated in breaker
compartment
Plenum Design
March 2008 - PASS
Arc out-gassing through plenum
No arc flash out of
the front of the
gear
24
Substations Without Main Secondaries
Substations Without Main Secondaries
Pri Fuse Only = 594
Calories
Pri Bkr Only= 289
Calories
Pri. Bkr + Maint. Switch=
7.5 calories
Substations Without Main Secondaries
ASTM F1506-02a - Standard Performance
Specification for Textile Material for Wearing
Apparel for Use by Electrical Workers Exposed
to Momentary Electric Arc and Related Thermal
Hazards, 2002a
Developed to give min performance specs for
protective clothing.
Major requirement being that the fabric is flame
resistant.
Results must be reported to the end user as an Arc
Rating on a garment label.
Sense at 480V TxmrTrip Primary
Use Group Settings for
ARMS
Many Variations
Must Meet ANSI
C37.59
ARC FLASH Avoidance:
Superior Protection with the Right Products
•
•
•
•
•
•
•
•
ASTM F1506 Standard
Retrofill Primary Fuse
with Mini Vac Bkr
MV AMPGARD
MV VCP-W
I/R Windows
FlashGard Motor Control Centers
Door Mounted Metering and Controls
Thru-Door racking capability
High Impedance Transformers
High Resistance Grounding
Definition of Arc Rating
Arc Rating
Previously the Arc Thermal Performance Exposure Value (ATPV)
Minimum incident thermal energy on a fabric or material that
results in sufficient heat transfer through the fabric or material to
cause the onset of a second degree burn based on the energy
transmitted through the clothing.
Arc Rating is expressed in cal/cm2. This energy is related to the
Stoll curve.
The Arc Rating is an average of 20 tests performed using the
ASTM F1959-99 standard.
25
Layering of FR Clothing
Layering of FR Clothing
Layering of Clothing
Layering significantly increases the level of protection.
Two thin layers are better than one thick layer.
Layer of air acts as a “buffer zone” between layers of
flame resistant fabrics.
Some multi-layer testing has been done by various fabric
manufacturers and ASTM Task Groups (varies
dramatically with different two-ply systems.)
Wear life & Laundering of FR
Clothing
Layering of FR Clothing
The single layer and multi-layer ratings for two FR fabrics are shown as
an example below:
Tested per ASTM F1959/F1959M-04 Standard Test Method for Determining the
Arc Thermal Performance Value of Materials for Clothing
Single-Layer Fabrics
INDURA® Ultra Soft®
Style 301
Style 801
Product / Style
Fabric Description
7oz (237g/m2) Shirting Twill
13oz (440g/m2) Heavyweight Sateen
ATPV
(cal/cm2)
8.7
Expected Lifetime and Effects of Cleaning
Wear life is affected by laundering.
Industrial laundering will create more wear on a garment
than home laundering.
Garments manufacturer’s provide the expected lifetime
based on use and laundering.
•
21.0
Multi-Layered Systems
•
ATPV
2
(cal/cm )
INDURA® Ultra Soft® Systems
301- 7oz (237g/m2) over 301- 7oz (237g/m2)
27.2
801- 13oz (440g/m2) Heavyweight Sateen over 301- 7oz (237g/m2)
51.5
•
FireWear - Inherently flame resistant, a characteristic that cannot be
degraded by laundering. Expected wear life of 18 to 30 months when
worn and home laundered once per week.
Nomex IIIa - Inherently flame resistant, a characteristic that cannot
be degraded by laundering. Expected wear life of 30-48 months.
Indura Cotton - Cotton fabric made flame resistant through an
ammonia cure process. Expected wear life of 12 to 18 months when
worn and home laundered once per week.
Laundering Instructions for
Indura Garments
Laundering Instructions for
Indura Garments
Washing
Washing
Wash Garments inside out
Do not use chlorine bleach
Do not overload washer
Do not use tallow soap: (One containing animal fats)
Use high water level
For optimum results use an acid sour.
Softened water provides the best results
Wash at temperature necessary to clean garment
(Maximum 165°F, or 74°C)
Use recommended amount of quality detergent.
(Phosphate can be used)
26
Laundering Instructions for
Indura Garments
Laundering Instructions for
Indura Garments
Drying
Pressing
Dry garments inside out.
Do not use extreme heat or leave in for long periods.
(Maximum stack temperature 165°F, or 74°C)
Press garment to remove wrinkles.
Use cotton setting.
Remove garment when slightly damp. Complete
drying on a hanger.
Garments may be line dried.
Specialized Arc Flash Protective
Equipment
ARC FLASH Avoidance:
Superior Protection with the Right Products
Specialized Arc Flash Protective Equipment
Flash Suits / Switching Coats
Two-Layer Flash
Suit,
ATPV = 42 cal/cm2
Use: Hazard/Risk
Category 4
We do we go from here?
1. Power System Studies
• Arc Flash Hazard Study
• Protective Device Coordination
• Short Circuit Study
• Updated Plant One-Line
• Arc-Flash Hazard Labels
2. Power Systems Training Program
• Understanding Arc-Flash
• Electrical & Arc-Flash Safety
3. Institute PPE Program
4. Vigilantly enforce Safety & PPE Program….Everyday
Thank You!
We sincerely thank you for your time!
27