1. arc flash basics The International Facilities
Management Association – Wichita Chapter
Presented By: Dee Jones, P.E.
Electrical Engineering Division of AVO Training Institute, Inc.
Introduction of speakers: give qualifications

2. Facility managers and arc flash safety
What is an arc flash?
What are the hazards and consequences of arc flash incidents?
What do I need to do to provide a safe work environment?
Specify that time spent on 1 and 2 will be short.

3. What is an arc flash? A rapid release of energy due to an arcing fault
- Phase-to-phase
- Phase-to-neutral
- Phase-to-ground
Air is the conductor during an arc fault

4. Arc Flash Video We have just viewed an arc flash at 138,000 volts
Now let us view one at 480 volts
What differences do you observe?

5. What is an arc flash?
Typically an arc flash could be over in less than 6 cycles which is 0.1 seconds (s)
0.1 s converted to milliseconds (ms) would be 100 ms The human eye blinks at 300 to 400 ms
The blink of an eye is 3 to 4 times slower than an arc flash

6. What is an arc flash/blast?
An arc blast is a multi-hazard event:
Arc flash (temperature rise, incident energy, UV)
Arc blast (explosion)
Expansion produces explosion with:
Molten metal
Vaporized metal (plasma)
Fragmented metal
High temperatures
Pressure on the body
165 db
Toxic fumes 6

7. < 740 mph IR
Visible
15000 °C
165 db UV
1000 °C
2000 psf
50 cal/cm2

8. WHERE DO I BEGIN? Arc Flash Hazard

9. PROCESS Understand the laws and regulations
Evaluate the degree and nature of the hazard
Begin or modify a safe work program
Select appropriate personal protective equipment (PPE)
Determine PPE supply and maintenance policy
Install warning labels on electrical equipment
Training
Implement or improve electrical equipment maintenance program
Ongoing review of hazards analysis and safe work program

10. fundamentals: Arc Flash Hazard

11. KEY ARC FLASH TERMS
Incident Energy: Amount of energy impressed on a surface, a certain distance from the source, generated during an electric arc event.
Based on:
Available fault current (amperage)
Distance from the equipment (feet and inches)
Fault clearing time (seconds or cycles)

12. KEY ARC FLASH TERMS Units of Measurement:
Calories per centimeter squared (cal/cm2)
FR clothing rated in arc thermal performance value (ATPV), given in cal/cm2
1 cal/cm2 is equivalent to the energy produced from a
lighter in one second
1.2 cal/cm2 causes beginning of 2nd degree burn
10.7 cal/cm2 causes beginning of 3rd degree burn

13. KEY ARC FLASH TERMS Limited approach boundary
Shock hazard exists
Restricted approach boundary
Increased shock hazard due to electric arc over combined with inadvertent movement
Prohibited approach boundary
Same as making contact
Arc Flash Protection boundary
An approach limit within which a person could receive a 2nd degree burn
NFPA 70E® pg 10 13

14. KEY ARC FLASH TERMS
Arc Flash Hazard: 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. Under normal operating conditions, enclosed energized equipment that has been properly installed and maintained is not likely to pose an arc flash hazard. 14

15. DE-ENERGIZED WORK
Working on de-energized equipment Equipment is not considered de-energized until absence of voltage is verified. PPE MUST BE WORN. Once absence of voltage is verified and equipment is grounded with lock out/tag out in place work can proceed without further arc flash clothing requirements. 15

16. arc flash effects
NIOSH studies show that employees are hospitalized every day with electrical arc flash related burns
NFPA 70E® states that over 2,000 people are admitted into burn centers each year with severe electrical burns (2-6 months average stay). NFPA 70E® Pg. 87

17. Rules and regulations: Arc Flash Hazard

18. Rules and Regulations OSHA 1910.132 (d) NFPA 70E®
• Requires employers to assess the workplace to determine if hazards are or are likely to be present and assign PPE appropriate for the hazards
• References NEC®, NFPA 70E® and IEEE standards
NFPA 70E®
• Requires a hazard analysis be performed and documented to determine the incident energy exposure of the worker, flash protection boundary and PPE usage based upon the associated hazard
• Provides procedure for performing hazard analysis calculations
NESC, ANSI-C2
• Requires flash hazard analysis completed by January 1, 2009 (specifically enforced for utilities)
IEEE 1584 • Provides procedure for performing hazard analysis calculations

19. NON-COMPLIANCE
U.S. Postal Service faces nationwide complaint for electrical safety violations
… The Occupational Safety and Health Administration (OSHA) issued fines totaling more than $6.2 million …for willful and serious electrical safety violations at 30 U.S. Postal Service (USPS) … facilities across the country.
…untrained or unqualified workers performing tests
…inadequate personal protective equipment (PPE) and warning signs
…The postal Service exposed workers … to the serious and potentially fatal hazards of shock, electrocution, and arc flash..
EC&M magazine Jan. 24, 2011 by Beck Ireland 19

20. NON-COMPLIANCE - VIDEO BACKGROUND
Information from an article by Ken Mastrullo in Fall 2004 NETA World Magazine
“Electrical Safety Should Never
Take a Holiday”
Perform preventive maintenance on Memorial Day morning
Open 15 kV switch to start emergency generator
Run generator for 3 hours under load to test reliability of system
All workers had minimum of 5 years of experience

21. NON-COMPLIANCE - 15kV Arc-Flash Video

22. NON-COMPLIANCE - Effect on workers
Two workers had serious 2nd and 3rd degree burns
One of the workers was burned over 60% of his body
The third worker has suffered long term effects, including neurological problems
Three families will never be the same again

23. NON-COMPLIANCE - Post evaluation
No hazard analysis
Workers were not properly trained (qualified)
Workers were wearing poly-blend clothing
All three workers were within the flash protection boundary

24. NON-COMPLIANCE - End results
OSHA citations and fines
- 5 serious
- 2 willful
- >$100,000
Medical expenses
Litigation
Negative publicity
They are required to do an OSHA mandated arc flash analysis

25. RESULTS OF Non-Compliance

26. RESULTS OF Non-Compliance

27. RESULTS OF Non-Compliance
He did fully recover!
He was LUCKY!!

28. Evaluate the degree and nature of the hazard NFPA 70E

29. NFPA 70E TABLES
When the NFPA 70E® Table 130.7(C)(9) is used in lieu of an arc flash hazard analysis, the notes for available fault current and clearing time must be used This table is limited in application because available fault current and clearing times may not correspond to the notes Refer to NFPA 70E, Paragraph 130.7(C)(9): “The assumed maximum short-circuit current capacities and maximum fault clearing times for various tasks are listed in the notes…” “…for power systems with greater than the assumed maximum short circuit current capacity or with longer than the assumed maximum fault clearing times, an arc flash hazard analysis shall be required…” NFPA 70E® Pg 29

30. NFPA 70E® TABLE 130.7(C)(9)
600 V Class Motor Control Centers (MCCs) – Note 2 (except as indicated)
Perform infrared thermography and other non-contact inspections outside the restricted approach boundary 1 N
CB or fused switch or starter operation with enclosure doors closed
600 V Class Switchgear (with power circuit breakers or fused switches) – Note 4
Perform infrared thermography and other non-contact inspections outside the restricted approach boundary 2 N
CB or fused switch or starter operation with enclosure doors closed 30

31. NFPA 70E® TABLE 130.7(C)(9) NOTES
Maximum of 25 kA short circuit current available; maximum of 0.03 sec (2 cycle) fault clearing time.
Maximum of 65 kA short circuit current available; maximum of 0.03 sec (2 cycle) fault clearing time.
Maximum of 42 kA short circuit current available; maximum of 0.33 sec (20 cycle) fault clearing time.
Maximum of 35 kA short circuit current available; maximum of up to 0.5 sec (30 cycle) fault clearing time. 31

32. NFPA 70E TABLES
The Tables should be used primarily for contractors. Contractors are not responsible for arc flash hazard analysis. The owner of the property is responsible (NFPA 70E, Relationships with Contractors (Outside Service Personnel, etc.). Secondarily the Tables with notes should be used for interim use until owners complete their arc flash hazard analysis NFPA 70E® Pg Tables provide no guidance for locations exceeding 40 calories. These locations must be identified. 32

33. Arc Flash Hazard Analysis NFPA 70E

34. What is arc flash hazard analysis?
Mathematical methods used to determine and reduce, where possible, the risk of personal injury as result of exposure to incident energy from arc flash
Identifies:
Incident energy exposure of the worker
Flash protection boundary
Appropriate work distance
Required PPE 34

35. What is arc flash hazard analysis?
Arc flash hazard expressed in incident energy
Arc flash protective clothing is rated in arc thermal performance value (ATPV)
ATPV is expressed in cal/cm2 35

36. ARC FLASH HAZARD ANALYSIS
For the best results on an arc flash hazard analysis:
Use a registered Professional Engineer (PE)
Calculation engineering software or equivalent qualified staff to perform and review results
Dedicated time and resources
Have a clearly defined scope of work and deliverables 36

37. ENGINEERING: Arc Flash Hazard Analysis

38. ENGINEERING ANALYSIS PROCESS
1. One-line Diagrams
2. Data Gathering
3. System Modeling
4. Short Circuit Study
5. Protective Device Coordination Study
6. Arc Flash Hazard Analysis
7. Written Reports
8. Labels 38

39.   USE CORRECT SIGNAGE Using generic arc flash hazard warning labels:
National Electrical Code (NEC®)
Requires flash protection field
marks for equipment with live
working condition
Refers to ANSI Z ,
Product Safety Signs and Labels,
for the design of safety signs and
labels  
Replace Warning sign with new sign 39

40. LABEL THE EQUIPMENT
Required by NEC

41. Implementation After Completion of the Arc Flash Hazard Analysis

42. IMPLEMENTATION Implement your results Allocate time and resources
It can only make your facility safer
Allocate time and resources
PPE
Develop and implement an Electrical Safety Program
Training
Implement a preventive maintenance program

43. Personal Protective Equipment Selection

44. Protective equipment
If the arc flash hazard analysis is completed properly:
The PPE requirements will be specific
PPE purchases can be specific to the need
PPE will be adequate but not excessive
PPE will meet the requirements and intent of OSHA
Most importantly PPE will protect the workers from recognized hazards

45. EXAMPLES OF ARC FLASH PPE
Balaclava w/face shield
Note 7 – face shield with a minimum arc rating of 4 for hazard risk category 1 with wrap-around guarding to protect not only the face, but also the forehead, ears, and neck (or an arc flash suit hood) is required.
multi-layer flash hood
Various combinations
Flash Suit
Balaclava (sock hood) 45

46. PERSONAL AND OTHER PROTECTIVE EQUIPMENT
NFPA 70E, 130.7
Includes:
Arc-rated jacket, parka, or rainwear
Hard hat
Safety glasses or safety goggles
Hearing protection (ear canal inserts)
Leather gloves
Leather work shoes 46

47. ELECTRICAL SAFETY PROGRAM: Develop and Implement

48. Your first choice should be to reduce or
arc flash prevention
PPE is the last line of defense in the event of an arc flash incident
“The protection is not intended to prevent all injuries but to mitigate the impact of an arc flash upon the individual, should one occur. In many cases, the use of PPE has saved lives and prevented injury.” IEEE Std , page 4
Your first choice should be to reduce or
eliminate the hazard! 48

49. TRAINING: Develop and Implement

50. PLAN FOR TRAINING OSHA AND 70E REQUIREMENTS
OSHA and NFPA 70E require training as part of the electrical safety program. You can now customize this training to include the results of your Arc Flash Hazard Analysis

51. MAINTENANCE: Develop and Implement an Maintenance Program

52. INADEQUATE EQUIPMENT MAINTENANCE
Example:
A low-voltage power circuit breaker has not been operated or maintained for several years
The lubrication has become sticky or hardened
The circuit breaker could take additional time to clear a fault condition 52

53. INADEQUATE EQUIPMENT MAINTENANCE
Two flash hazard analyses will be performed using a 20,000-amp short-circuit with the worker 18 inches from the arc:
Based on what the system is supposed to do 0.083
seconds (s) (5 cycles)
Due to a sticky mechanism, the breaker now has an
unintentional time delay of 0.5 s (30 cycles) 53

54. INADEQUATE EQUIPMENT MAINTENANCE
(1) DB = 18 in.
(2) tA = second (5 cycles)
(3) F = 20kA
EMB = DB tA[0.0093F F ]
= 1038x0.0141x0.083[0.0093x x ]
= x[2.7815]
= 3.5 cal/cm2
NFPA 70E-2009, Section 130.3(B)(1) requires arc-rated FR clothing and other PPE to be selected based on this incident energy level exposure. Therefore the FR clothing and PPE must have an arc rating of at least 3.5 cal/cm2.
NFPA 70E® pg 54

55. INADEQUATE EQUIPMENT MAINTENANCE
(1) DB = 18 in.
(2) tA = 0.5 second (30 cycles)
(3) F = 20kA
EMB = DB tA[0.0093F F ]
= 1038x0.0141x0.5[0.0093x x ]
= x[2.7815]
= 20.4 cal/cm2
NFPA 70E-2009, Section 130.3(B)(1) requires arc-rated FR clothing and other PPE to be selected based on this incident energy level exposure. Therefore the FR clothing and PPE must have an arc rating of at least 20.4 cal/cm2.
NFPA 70E® pg 55

56. PLAN FOR ANALYSIS MAINTENANCE
Analysis reviewed every 5 years, per NFPA 70E® 130.3
An analysis maintenance plan will integrate changes to the system over time
Maintenance of the database is more economical than starting from scratch
NFPA 70E® Pg. 25

57. CONCLUSION: Arc Flash Hazard Analysis

58. Arc Flash CASE History Video
This video is produced by Dow Chemical and is a report of an actual arc flash incident where proper PPE was utilized and the employee was not injured.

59. conclusions Perform the Analysis Do nothing Require incorrect PPE
Arc Flash Hazard Analysis is risk management. You have 3 choices.
Do nothing
Fatality/injury
Treatment costs
Fines
Litigation
Insurance
Perform OSHA mandated Analysis
Require incorrect PPE
Inadequate or excessive PPE
Perform the Analysis
Performed by a Registered Professional Engineering Firm
Issue the analysis report with results
Make recommendations 59

60. AVO Electrical Engineering Division
Dee Jones, P.E.
Principal Engineer and Division Manager
x 7347
Direct:
Leisa Busbea
Corporate Sales & Development
x 7318
Direct: