Preventing Arc Flash Injuries:
Engineering is A Science, Safety
is a Culture
Presented by: Khadijah Latiff
Date: July 25, 2013
“Greeley and Hansen has met the standards and requirements of
the Registered Continuing Education Program. Credit earned on
completion of this program will be reported to RCEP at RCEP.net.
A certificate of completion will be issued to each participant. As
such, it does not include content that may be deemed or construed
to be an approval or endorsement by RCEP.”
2
Greeley and Hansen's Intellectual Property
Please be aware that this presentation
has been developed for
the exclusive use of Greeley and Hansen personnel
for training and other specific purposes.
As such, it is considered to be
the firm's intellectual property
and is not to be shared with
persons external to the firm or other organizations.
For additional information, refer to Greeley and Hansen’s
Employee Policy 104 – Non-Disclosure and Confidentiality
3
Topics
1. Introduction
to Electrical Hazards
2. Organizational and Behavioral Aspects of
Safety
3. Electrically Safe Environment
4. Arc Flash Study, PPE, Electrical Safety
Program
4
Introduction
Definitions
 Terminology
 ‘Live’ / Energized / De-energized
 Personal Protective Equipment (PPE)
 Electrical Equipment
 Short circuit
 Fault current
 Protective device
6
Resources

NIOSH – National Institute of Occupational Safety and
Health
7
Shock Hazard vs Arc Flash
Electrical
Hazards
Contact with
current-carrying
conductor
Arc Flash
Arc Blast
Electric
Shock
Arc ‘blast’ is a high pressure
sound wave caused by an
arc fault
Electric ‘arc’ – high temperature
discharge of current through air
8
Shock Hazard vs. Arc Flash
1. Shock
Hazard:
 Current, I = V / Rbody
 Current path
 ~5mA pain/perception
 ~10mA let-go-threshold
 ~100mA (0.1A) heart fibrillation, skin burns
9
Shock Hazard vs. Arc Flash
1. Shock
Hazard: VOLTAGE
 Higher the Voltage, Higher the Hazard
 Defines
 Limited Approach Boundary
 Restricted Approach Boundary
 Prohibited Approach Boundary
10
Shock Hazard vs. Arc Flash
1. Arc
Flash Energy: Available fault current
AND fault clearing time
 Available fault current (Isc)
 Protective device fault clearing time
(t = 0.0 – 0.2s)
 Higher exposure time, higher the hazard
 Defines Arc Flash Boundary
11
Arc Flash Hazard
12
Determining the Flash Protection
Boundary
1. Distance within which second degree
burn is possible
2. Based on arc flash incident energy (cal/
cm2)
3. 1.2 cal/cm2 is threshold for onset of
second degree burn
13
Causes of Arc Flash
Main Causes
Improper
Negligent
equipment/
preventative Human error
system
maintenance
design
14
Discrepancy in Approach
Equipment Human
Failure
Error
Engineering
Design
Human Behavior
15
Existing Approach to Arc Flash
1.
2.
3.
Regulatory
 OSHA 29CFR 1910
 NFPA 70E
 NEC article 110.16
 IEEE 1584
Technical
 Electrical and Arc Flash Hazard Analysis
 Personal Protective Equipment (PPE)
 Equipment marking (labels)
Arc Flash Mitigation Technologies
 Arc Flash resistant switchgear
 Optical or arc pressure sensors
 High resistance grounding equipment
What are we
missing?
16
Risk Assessment Model
Safety Management
Hazard Identification
Design Control
Arc rated equipment
Design Engineering
Protective Devices
Information (study)
Organization
(administrative and
behavioral controls)
System that increases awareness
Training/Procedures
Work organization & instruction
Personal protective equipment
Communication
Verification, validation,
documentation
17
Organizational and Behavioral
Aspects of Safety
Importance of Safety Mentality
“I have sat through safety meetings before,
thinking the whole time that the only reason for
the meeting was to meet some company
insurance requirement or the company just
trying to cover itself in case an accident
happened."
- experienced service electrician, trained
“What could possibly happen, as long
as I am careful? I have done this a
million times before.”
“All that (PPE) gear is so hot and
bulky.”
19
NIOSH Study (Electrocution Deaths - 1980-1992)
90
Rate per 100,000 Workers
80
70
60
50
40
30
20
10
0
16-19
20-24
25-34
35-44
45-54
55-64
65 or >
411 deaths by electrocution per year
20
NIOSH Study (Electrocution Deaths - 1980-1992)
1. Contributing
Factors:
 Safe work procedures not implemented or




followed
PPE was not provided or worn
LOTO procedures not implemented or followed
Lack of compliance with OSHA, NEC, NESC
Inadequate worker and supervisor training
21
Negative Habits
1. Hard
mentalities:
 Complacency
 Arrogance
 Ignorance
 Incompetence
 Silence
22
Negative Habits
1. Complacency
 Putting comfort ahead of safety
 Underestimating risks in performing
routine tasks
 Habit of relying on experience
 Neglect of housekeeping, maintenance,
cleanliness of workplace
23
Negative Habits
1. Arrogance
 Knowingly violating safety rules and
procedures
 Taking shortcuts to save time
 Performing work without approved
energized work permit
 Treating job briefings and training as mere
formality
24
Negative Habits
1. Ignorance
 Inability to recognize source of hazard
 Accidents involving unqualified persons in
hazardous areas
25
Negative Habits
1. Incompetence
 Lack of specific training
 Lack of job preparation
 Fail to think through job
 Under pressure to the point of
incompetence
26
Negative Habits
1. Silence
 Seeing unsafe work conditions and not
speaking up
 Fear of blame or negative action from
management
27
Investing in Values and Culture
1.
2.
3.
4.
5.
A complicated safety implement is only as good as the
operator operating it
An electrical hazard assessment report is only good if it is
used and understood
An arc flash hazard label is only good if it is readable and
understood
PPE is only good if it is WORN
Values and culture will outlast any technology
28
Creating Electrically
Safe Environment
Fundamentals of Electrical Safety
De-energize and isolate
2. Test, to verify equipment de-energized
3. Having clearly defined justifications and
required authorization for energized
work permit
1.
30
Energized Work Permit
1. Part
I – To be completed by requester
 Description of circuit, equipment, location
 Description of work
31
Energized Work Permit
1. Part
II – To be completed by person
doing the work
 Must be an electrically qualified person
 Detailed description of procedures
 Description of safe work practices to be

employed
Documentation of hazard analysis and job
briefing
32
Energized Work Permit
1. Part
III – Approval
 Maintenance/Engineering Manager
 Electrically Knowledgeable Person
 Safety Manager
 Operations Manager
 General Manager
33
Work Permit Flow Chart
Is potential
exposure to
energized parts
less than <50V?
Are there other
sources of hazard, ie
capacity of source,
overcurrent
protection between
source and worker?
Yes
Yes
No
Can an electrically
safe work
condition be
established (ie
Yes
No
Follow safe work
practice, wear
appropriate PPE and
complete the task
Coordinate
shutdown. Follow
LO/TO procedures
No
No
Refer to task table
for guidelines on
permit
requirement. Is
Request
denied
Yes
Obtain Energized
Electrical Work
Permit and begin
assesment
All levels of
approval not
Live work is not justified
according to criteria
(increased hazards when
coordinating shutdown,
infeasibility to de-energize due
to equipment design or
Live work is
justified and all
levels of approval
obtained
Arc Flash Study, PPE &
Equipment Labels
Power Systems Analysis
1. Short
circuit study – available fault
current
2. Coordination study – shows coordination
of protective devices
3. Arc Flash study – provides incident
energy, hazard risk category, PPE
36
Hazard Risk Categories
 As
determined by Arc Flash study
Incident Energy
Hazard Risk Category
Less than 1.2 cal/cm2
0
1.2 – 4 cal/cm2
1
4 – 8 cal/cm2
2
8 – 25 cal/cm2
3
25 – 40 cal/cm2
4
Above 40 cal/cm2
Dangerous!
37
Simplified Two-Category Clothing
System
Clothing
Hazard/Risk Category
Everyday Work Clothing
Arc-rated long-sleeve shirt with Arc-rated pants (minimum
arc rating of 8)
or
Arc-rated coveralls (minimum arc rating of 8)
0, 1, 2
Arc Flash Suit
A total clothing system consisting of arc-rated shirt and
pants and/or arc-rated coveralls and/or arc flash coat and
pants (clothing system minimum arc rating of 40)
3, 4
Table H.2 Simplified, Two-Category, Arc-Rated Clothing System
Head protection, hearing protection
 Insulated, arc-rated gloves
 Safety glasses/goggles
 Leather work shoes

38
Arc Flash Suit
1. Common
cause of disregard:
 Discomfort
 Obstructed vision
 Interferes with task
39
Equipment Marking
NEC Article 110.16
NFPA 70E 130.5(C)
To think about:
 Quality (information, readability)
 Context (general, specific, understandable?)
 Quantity (too many, too few)
 Placement (visibility)
40
Electrical Safety Program
Electrical Safety Program
110.3 Electrical Safety Program
(A) General. The employer shall implement and document an overall
electrical safety program that directs activity appropriate for the
electrical hazards, voltage, energy level, and circuit conditions.
(B) Awareness and Self-Discipline. The electrical safety program
shall be designed to provide an awareness of the potential electrical
hazards to employees who work in an environment with the presence
of electrical hazards. The program shall be developed to provide the
required self-discipline for all employees who must perform work that
may involve electrical hazards. The program shall instill safety
principles and controls.
NFPA 70E
42
Electrical Safety Program
Electrical Safety Program should outline:
1. Principles

2.
Controls

3.
Training, skills assessment, hazard identification, policies, maintenance,
anticipate unexpected events
Precautions and steps, methods, de-energizing safely, categorization of
tasks and PPE level
Procedures

Qualifications, job briefing, limitations, electrical diagrams, reference
material, checklist, PPE, tools, limits of approach
43
Electrical Safety Program
1. Think
about:
 Developing electrical safety program that is site




specific, not cut-and-paste job
Employees have different skill and experience
levels
Updated periodically with system upgrades
Perform electrical safety auditing
Document training and retraining
44
Challenges
1. Working
with contractors and outside
service personnel
 Host employer responsibilities
 Job briefings, site review, documentation
 Importance of having a qualified, trained,
knowledgeable person to assist contractors
45
Summary
1.
Safety is not merely compliance
 Human error is a variable factor
 Human behavior is complex
 Attitude towards hazard and danger largely depend on the
understanding/awareness
2.
3.
Creating a safety culture
 Addressing behavioral component
 Creating awareness and self discipline
 Using knowledge and judgment
There is no one-size fits all solution
46
Thank you for your time!
QUESTIONS?
This concludes the educational content of this activity
47
SAVE THE DATE!
May 23, 2013 at 12pm CST
Sustainable Design Challenge
By: John Lenti
Answers to Quiz





1. a)
2. a)
3. b)
4. b)
5. c)





6. d)
7. a)
8. b)
9. d)
10. a)
49