GE Energy

Arc-Flash Hazard

Analysis

WMEA

Photo courtesy of SquareD and Schneider Electric.

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Source: NFPA 70E 2004 Edition–Article 100

Flash HazardA dangerous condition associated with the release of energy caused by an electric arcFlash Hazard AnalysisA study investigating a worker’s potential exposure to arc-flash energy, conducted for the purpose of injury prevention and identifying NFPA-based safe work practices and calculating the NFPA-based levels of PPE

Defining Flash Hazards & Analysis

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Frequent Causes of Arc-Flash Hazards• Extended maintenance cycles• Extreme environments• Improper PPE• Missing or ineffective hazard labeling• Unsafe work practices • Complacency

Photo courtesy of Easypower.com

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Drivers for Arc-Flash Hazard Analysis

• Employee safety• Industry standards

–NFPA standards–IEEE standards–OSHA

• Financial liability–Regulatory fines–Litigation potential–Lost production–Insurance premiums

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Employee Safety

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Arc-Flash Injury PotentialPotential Health Impacts – Burns, Lacerations, Concussions, Broken Bones, Vision Impairment, Fatality• Arc-flash injuries occur daily in the U.S.

requiring hospitalization

• Arc-plasma temperatures may reach 35,000°F (~ 4 x hotter than the sun’s surface)

• 80% of all electrical injuries are burns from electric arc-flash and ignition of employees' clothing

Courtesy of Coastal Video and Joetedesco.com

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Traditional Studies are InsufficientArc-Flash builds upon your commitment to safety demonstrated through traditional power system studies

GE has over 100 years experience in performing power system studies

Arc-Flash Utilizes Results from:• Short-circuit analysis• Protective device coordination study• Load flow analysis• Harmonic analysis• Motor starting study• Transient stability

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Securing Safety is in the DetailsArc-Flash Hazard Analysis will calculate:• NFPA-based level of PPE required • Areas where PPE can not provide protection

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Industry Standards

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Industry Standards include:• NFPA 70, National Electric Code 2005 (110.16)

• NEC 2005 Handbook• OSHA 29 CFR 1910.269; OSHA 1910.132(d)(1)

• IEEE Std 1584-2002, IEEE Guide for Performing Arc-Flash Hazard Calculations and IEEE Std. 1584a-2004 (Amendment 1)

• NFPA 70E, Standard for Electrical Safety in the Workplace 2004 Edition, 130.3(B)

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OSHA Interpretation“Though OSHA does not, per se, enforce the NFPA standard, 2004 Edition, OSHA considers NFPA standard a recognized industry practice. The employer is required to conduct assessment in accordance with CFR 1910.132(d)(1). …Employers who conduct the hazard/risk assessment … as stated in the NFPA 70E standard, 2004 Edition, are deemed in compliance with the Hazard Assessment and Equipment Selection OSHA standard.”Richard S. Terrill, the Regional Administrator for Occupational Safety and Health, US Department of Labor for the Northwest Region at Seattle

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OSHA 1910 Subpart S Revisions Effective Aug 13th, 2007NFPA 70E-2000 is the basis for most of the final rule. However, there are some parts based upon the 2002 NEC and even some selected parts of NFPA 70E 2004 Edition.

“… The Agency intends to extend the commitment by using NFPA 70E as a basis for future revisions to its electrical safety-related work practice requirements and new requirements for electrical maintenance and special equipment.”

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Arc-Flash Hazard Analysis ApplicabilityElectrical equipment such as:• Switchgear• Switchboards• Panelboards• Motor Control Centers

All live electrical equipment:• 250V and up• 208V and 240V systems fed from 125kVA

transformers and up

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Financial Liability

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Ford Motor Company -Financial Liability

• $14,000 fine• Required to implement hazard analyses at its 37 manufacturing facilities and parts distribution centers in the US

Settlement: U.S. Dept. of Labor, OSHRC Docket 00-0763

Injured employee did not properly lock-out nor test for voltage, but Ford was held

liable, in part, for not using NFPA

guidelines to define hazards and specify

PPE

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OSHA–Issuing Fines for Non-Compliance

•$193,000 - Pieper Electric•$80,000 - Narragansett Electric Company, Inc.…Failure to instruct on unsafe conditions,

provide appropriate PPE… and identify the location of energized equipment and protective measures to be taken…

Recent Citations under OSHA’s General Duty Clause:

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GE Energy’s Arc-Flash Analysis

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Creating Confidence

Identify Systems

Data Collection

Verification

Develop Analysis Models

Perform System Analysis

Analyze Results

Implement Solution

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Expanded Analysis Results Minimum deliverables for each system location:• Calculated IEEE-based incident energy and Arc-

Flash protection boundary with the corresponding NFPA-based PPE class

• Arc-Flash and shock hazard labels

Additional benefits from GE Energy’s analysis:• Uncover power system operational or design issues• Uncover incorrect equipment trip settings• Identify opportunities to improve system reliability,

efficiency, capacity, maintenance and safety

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Arc-Flash Hazard PPE RequirementsTable 130.7(C)(11) Protective Clothing Characteristics

From NFPA 70E 2004 Edition –

Typical Protective Clothing System s

Hazard / Risk Category

Clothing Description (Typical num ber of clothing layers

is given in parentheses)

Required M inim um Arc Rating of PPE [J/cm 2 (cal/cm 2)]

0 Non-m elting, flam m able m aterials (i.e., untreated cotton, wool, rayon, or silk, or blends of these m aterials) with a fabric weight at least 4.5 oz/yd2 (1)

N/A

1 FR shirt and FR pants or FR coverall (1) 16.74 (4) 2 Cotton underwear— conventional short sleeve

and brief/shorts, plus FR shirt and FR pants (1 or 2)

33.47 (8)

3 Cotton underwear plus FR shirt and FR pants plus FR coverall, or cotton underwear plus two FR coveralls (2 or 3)

104.6 (25)

4 Cotton underwear plus FR shirt and FR pants plus m ultilayer flash suit (3 or m ore)

167.36 (40)

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Limits of Approach

Limited Approach Boundary (Shock protection boundary)Distance from an exposed live part where a shock hazard exists

Flash Protection BoundaryDistance from exposed live parts where a person could receive a second degree burn if an electrical arc flash were to occur

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Limits of Approach (cont.)Restricted Approach Boundary (Shock protection boundary) Distance from an exposed live part where there is an increased risk of shock from electrical arc-over combined with inadvertent movement

Prohibited Approach Boundary (Shock protection boundary)Distance from an exposed live part where work is considered the same as making contact with the live part

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Arc-Flash Hazard and Shock Hazard Equipment LabelsLabels for each system location• Arc-Flash hazard boundaries• Shock hazard boundaries• Combined levels of PPEDesigned for industrial environment• Highly visible• 5” x 3-5/8”• Chemical resistant• UV resistant• Washable/durable

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Arc-Flash Hazard Work PermitsWork permits (by employer):• Description and location of

circuit/equipment• Justification for energized work• Shock hazard protection

boundaries

Required by: NFPA 70E Section 110.8(B)(2) and 130.1(A)

If live components are not placed in electrically safe work condition, then it is considered energized electrical work, and a written permit is required

• Arc-flash hazard protection boundaries• PPE and access restrictions• Job briefing with discussion of job-specific

hazards• Work approval signature

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Bringing Experience and KnowledgeWorld-leading power system experience with:• Industry specific applications• Power system equipment • Greenfield solutions• Service, local presence on a global scaleCurrent with NFPA and related standards via:• Participation in NFPA committees and

conferences • Monitoring industry and regulatory trends

APPENDIX - Backup slides

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Appendix - Arc-Flash Hazard Analysis

Power System Studies Overview–Short-circuit study–Protective device coordination study–Load flow–Harmonic analysis–Conceptual design

Pieper Electric Citation ExcerptsReference NFPA 70E StandardsReference OSHA Materials

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Short-Circuit Study

• Periodically ensures system protection devices are correctly rated

• Provides fault information for setting overcurrent devices

• Performed when utility’s available short circuit current is increased

• Performed when substantial systems modifications are planned i.e. lines, motor or generation changes

• Assists in conceptual design• Needed for Arc-Flash study

Short-Circuit Study Results

IEEE Std. 141-1993 – Red Book

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Protective Device Coordination Study

• Analyzes over-current protection devices ability to protect components

• Provides over-current device settings for relays, breakers, etc. (using short-circuit study results)

• Isolates system faults, minimizing damage

These five protective devices are set so that

they work together to trip and isolate the smallest

possible area of the power system…

IEEE Std. 242-2001 – Buff Book

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Load Flow Study• Supports conceptual design • Determines when system

components are overloaded and system modifications are needed

• Performed when voltage performance is inadequate

• Determines power factor correction to increase system capacity and reduce utility costs

• Impact loads modeled to see system effects

Load Flow results showing watt/var flows

and the resulting system

voltages (in p.u.)

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Harmonic Analysis Study• Used to understand system

harmonics caused by drives, UPS systems, arc furnaces, etc.

• Needed for selecting capacitors for voltage/power factor improvement in a harmonic-rich environment

• Needed to design harmonic filters

Harmonics appear as distortions of voltage and

current sine waves. Resonance can amplify

these harmonics creating system problems

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Conceptual Design Study• Maximizes benefits of capital

investments by producing a cost- effective system design for an existing or new facility

• Performed when the existing system is inadequate to serve its loads

• Performed when a substantial power system expansion is planned

What could the power system look like in the

future?

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Pieper Electric OSHA Citation

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Pieper Electric OSHA Citation (Cont.)

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Pieper Electric OSHA Citation (Cont.)

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Pieper Electric OSHA Citation (Cont.)

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110.16 Flash ProtectionElectrical equipment such as* switchboards, panel- boards, 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.

NEC 2008 Standards for Flash Protection

The marking shall be located so as to be clearly visible to qualified persons before examination, adjustment, servicing, or maintenance of the equipment.

* New text for 2008 code.

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Reference NFPA 70E Standards• System One-Line - Section 205.2• Current Short Circuit Study – Section 400.5• Current Coordination Study – Section 400.6,

410.9(B)(1),(2),(3); 410.9 (C)(1),(2)• Flash Hazard Analysis – Section 110.8; 130.3(A),

(B)• Flash Protection Label - Section 400.11• Shock Hazard Analysis – Section 110.8(B)(1); 130.2• Personal Protective Equipment Requirements –

Section 130.7(C)• Work Permit – Section 110.8(B)(2); 130.1(A)

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Reference OSHA MaterialsOSHA 29 CFR 1910.269 states that “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.”OSHA 1910.132(d)(1) — The employer shall assess the workplace to determine if hazards are present, or are likely to be present, which necessitate the use of personal protective equipment (PPE). If such hazards are present, or likely to be present, the employer shall:OSHA 1910.132(d)(1)(i) — Select, and have each affected employee use, the types of PPE that will protect the affected employee from the hazards identified in the hazard assessment;OSHA 1910.132(d)(1)(ii) — Communicate selection decisions to each affected employee; and,OSHA 1910.132(d)(1)(iii) — Select PPE that properly fits each affected employee. Note: Non-mandatory Appendix B contains an example of procedures that would comply with the requirement for a hazard assessment.

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Reference Quote: Richard Terrill“Though OSHA does not, per se, enforce the NFPA standard, 2004 Edition, OSHA considers NFPA standard a recognized industry practice. The employer is required to conduct assessment in accordance with CFR 1910.132(d)(1). If an arc-flash hazard is present, or likely to be present, then the employer must select and require employees to use the protective apparel. Employers who conduct the hazard/risk assessment, and select and require their employees to use protective clothing and other PPE appropriate for the task, as stated in the NFPA 70E standard, 2004 Edition, are deemed in compliance with the Hazard Assessment and Equipment Selection OSHA standard.”

Richard S. Terrill, the Regional Administrator for Occupational Safety and Health, US Department of Labor for the Northwest Region at Seattle