preventing arc flash injuriesengineering is a science - sa 2 · “greeley and hansen has met the...

Preventing Arc Flash Injuries: Engineering is A Science, Safety is a CulturePresented 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.”

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Greeley and Hansen's Intellectual Property

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Please be aware that this presentationhas been developed for

the exclusive use of Greeley and Hansen personnelfor training and other specific purposes.

As such, it is considered to be the firm's intellectual propertyand 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

Topics

1. Introduction to Electrical Hazards2. Organizational and Behavioral Aspects of

Safety3. Electrically Safe Environment4. Arc Flash Study, PPE, Electrical Safety

Program

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Introduction

Definitions

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Terminology ‘Live’ / Energized / De-energized Personal Protective Equipment (PPE) Electrical Equipment Short circuit Fault current Protective device

Resources

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NIOSH – National Institute of Occupational Safety and Health

Shock Hazard vs Arc FlashElectrical Hazards

Arc Flash Arc Blast Electric Shock

Contact with current-carrying

conductor

Electric ‘arc’ – high temperature discharge of current through air

Arc ‘blast’ is a high pressure sound wave caused by an

arc fault

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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

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1. Shock Hazard: VOLTAGE Higher the Voltage, Higher the Hazard Defines

Limited Approach Boundary Restricted Approach Boundary Prohibited Approach Boundary

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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

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Arc Flash Hazard

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Determining the Flash Protection Boundary1. Distance within which second degree

burn is possible2. Based on arc flash incident energy (cal/

cm2)3. 1.2 cal/cm2 is threshold for onset of

second degree burn

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Causes of Arc FlashMain Causes

Improper equipment/

system design

Negligent preventative maintenance

Human error

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Discrepancy in Approach

Equipment Failure

Human Error

Engineering Design

Human Behavior

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Existing Approach to Arc Flash1. Regulatory

OSHA 29CFR 1910 NFPA 70E NEC article 110.16 IEEE 1584

2. Technical Electrical and Arc Flash Hazard Analysis Personal Protective Equipment (PPE) Equipment marking (labels)

3. Arc Flash Mitigation Technologies Arc Flash resistant switchgear Optical or arc pressure sensors High resistance grounding equipment

What are we missing?

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Risk Assessment ModelHazard Identification

Arc rated equipment

Protective Devices

Information (study)

System that increases awareness

Training/Procedures

Work organization & instruction

Personal protective equipment

Verification, validation, documentation

Safety ManagementDesign Control

Design Engineering

Organization (administrative andbehavioral controls)

Communication17

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

“All that (PPE) gear is so hot and bulky.”

“What could possibly happen, as long as I am careful? I have done this a

million times before.”

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NIOSH Study (Electrocution Deaths - 1980-1992)

411 deaths by electrocution per year

90

80

70

60

50

40

30

20

10

0

16-19 20-24 25-34 35-44 45-54 55-64 65 or >

Rat

e pe

r 100

,000

Wor

kers

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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

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Negative Habits

1. Hard mentalities: Complacency Arrogance Ignorance Incompetence Silence

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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

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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

formality24

Negative Habits

1. Ignorance Inability to recognize source of hazard Accidents involving unqualified persons in

hazardous areas

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Negative Habits

1. Incompetence Lack of specific training Lack of job preparation Fail to think through job Under pressure to the point of

incompetence

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Negative Habits

1. Silence Seeing unsafe work conditions and not

speaking up Fear of blame or negative action from

management

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Investing in Values and Culture

1. A complicated safety implement is only as good as the operator operating it

2. An electrical hazard assessment report is only good if it is used and understood

3. An arc flash hazard label is only good if it is readable and understood

4. PPE is only good if it is WORN5. Values and culture will outlast any technology

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Creating Electrically Safe Environment

Fundamentals of Electrical Safety

1. De-energize and isolate2. Test, to verify equipment de-energized3. Having clearly defined justifications and

required authorization for energized work permit

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Energized Work Permit

1. Part I – To be completed by requester Description of circuit, equipment, location Description of work

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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

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1. Part III – Approval Maintenance/Engineering Manager Electrically Knowledgeable Person Safety Manager Operations Manager General Manager

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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?

Follow safe work practice, wear

appropriate PPE and complete the task

Can an electrically safe work

condition be established (ie

Coordinate shutdown. Follow LO/TO procedures

Refer to task table for guidelines on

permit requirement. Is

Obtain Energized Electrical Work

Permit and begin assesment

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

All levels of approval not

Request denied

No

Yes No

Yes

No

Yes

No

Yes

Work Permit Flow Chart

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

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Hazard Risk Categories

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!

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As determined by Arc Flash study

Simplified Two-Category Clothing System

Table H.2 Simplified, Two-Category, Arc-Rated Clothing System

Clothing Hazard/Risk Category

Everyday Work ClothingArc-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 SuitA 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

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Head protection, hearing protection Insulated, arc-rated gloves Safety glasses/goggles Leather work shoes

Arc Flash Suit

1. Common cause of disregard: Discomfort Obstructed vision Interferes with task

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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)

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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

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Electrical Safety Program should outline:1. Principles

Training, skills assessment, hazard identification, policies, maintenance, anticipate unexpected events

2. Controls Precautions and steps, methods, de-energizing safely, categorization of

tasks and PPE level

3. Procedures Qualifications, job briefing, limitations, electrical diagrams, reference

material, checklist, PPE, tools, limits of approach

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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

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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

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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. Creating a safety culture Addressing behavioral component Creating awareness and self discipline Using knowledge and judgment

3. There is no one-size fits all solution46

QUESTIONS?

Thank you for your time!

This concludes the educational content of this activity

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Sustainable Design Challenge

By: John Lenti

SAVE THE DATE!

May 23, 2013 at 12pm CST

Answers to Quiz

1. a) 2. a) 3. b) 4. b) 5. c)

6. d) 7. a) 8. b) 9. d) 10. a)

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preventing arc flash injuriesengineering is a science - sa 2 · “greeley and hansen has met the...

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