2. Importance of Arc Flash Analysis (“Arc Flash Loss Prevention”)
Provides minimum requirements to prevent hazardous electrical exposures to personnel and ensure compliance with regulatory requirements applicable to electrical systems

3. Regulatory Requirements (elements necessary for Worker Safety)
OSHA = Shall Provide Worker Safety
NFPA 70E = How to provide Worker Safety
Employer Responsibility = Execution
Focus on safety, promote training, use best practices

4. Electrical Hazards Consist of:
Electric Shock
Arc Flash
Arc Blast
Other Hazards

5. Electric Shock
An electric shock occurs when electric current passes through the body. This can happen when touching an energized part. If the electric current passes through the chest or head, death can result.

6. Effects of Electrical Current in the Human Body
Below 1 milliampere: - Generally not perceptible
1 milliampere: - Faint tingle
5 milliamperes: - Slight shock felt; not painful but disturbing. Average individual can let go. Strong involuntary reactions can lead to other injuries.
6–25 milliamperes (women): - Painful shock, loss of muscular control*
9–30 milliamperes (men): - The freezing current or " let-go" range.* Individual cannot let go, but can be thrown away from the circuit if extensor muscles are stimulated.
50–150 milliamperes: - Extreme pain, respiratory arrest, severe muscular contractions. Death is possible.
1,000–4,300 milliamperes: - Rhythmic pumping action of the heart ceases. Muscular contraction and nerve damage occur; death likely.
10,000 milliamperes: - Cardiac arrest, severe burns; death probable* If the extensor muscles are excited by the shock, the person may be thrown away from the power source. Source: W.B. Kouwenhoven, " Human Safety and Electric Shock," Electrical Safety Practices, Monograph, 112, Instrument Society of America, p. 93. November 1968.

7. Arc Flash/Blast
An arc flash (also known as arc blast) is a sudden, explosive electrical arc that results from a short circuit through air. The air in the vicinity of an arc flash is heated to between 5,000 and 35,000 degrees in no more than 1/1000 of a second, becoming an electrically-conductive plasma. The sudden heating can cause a shock wave blast equivalent to several sticks of dynamite and carrying vaporized metal and shrapnel

8. Safe Work Practices OSHA 1910.333 NFPA 70E 110.8
Potential for shock or other injury
Working on or near live exposed parts
Practices must be consistent with the extent of the hazard
NFPA 70E 110.8
Requires deenergizing
Requires worker to be qualified
Requires hazard analysis
Electrical work permit

9. NFPA 70E Requirements for Working on or Near Live Parts
Perform Arc Flash Analysis
Select Personal Protective Equipment (PPE)
Complete Energized Electrical Work Permit
Complete Task Specific Training
Complete a job briefing session

10. Arc Flash Analysis Establish Shock Protection Boundary
(approach boundaries) – used to reduce shock hazard
Conduct Flash Hazard Analysis
Establish Flash Protection Boundary
Used to reduce arc flash hazards and may reduce arc blast hazards
Select Personal Protective Equipment
Analysis per NFPA 70E requires update every 5yrs

11. Approach Boundary to Live Parts
Limited (42 in)
Restricted (12 in)
Prohibited (1 in)
Based on system voltage = 480V
NFPA 70E, Annex C, Figure C.1.2.4

12. Flash Protection Boundaries (FPB)
Using NFPA 70E, the methods to determine FPB
Defaults (i.e. tables)
Perform Analysis that uses Calculation Methods

13. Levels of Exposure

14. Personal Protective Equipment (PPE)

15. PPE Designed to protect specific areas of the body Eye Protection
Neck, Face, Head, Chin
Arm & Hand Protection
Body Protection
Leg & Foot Protection

16. PPE - Gloves
Voltage rated gloves are REQUIRED for all voltage testing above 50 volts

17. OSHA/NFPA 70E General Industry Requirements
OSHA (a)
Employees exposed to potential electrical hazards shall use protective equipment that is appropriate for the specific areas of the body to be protected and for the work to be performed
NFPA 70E 130.7
Provides standards for equipment
Hazard Risk Table
PPE Matrix
Extensive detail for worker protection
Protective Equipment

18. OSHA Fines
For non-compliance, OSHA may audit a facility and issue fines
Most recently: U.S. Postal Service
$420,000 (pending) – single facility

19. A Facility’s Electrical System
A facility’s electrical system operates as a single, dynamic system. Its performance is dependent on the properties of each component and the loads connected to it.
Many facilities expand project by project using different design and construction teams. Even though each specific project may be well planned and designed, it’s often the case that the area of work specific to the project is limited to only a portion of the existing electrical distribution system.
In addition, due to the need for maintenance and emergency repairs, system components are often replaced with devices that are different than originally installed due to availability and cost.
Because of these occurrences, it’s common that no one has an overall and complete understanding of the entire electrical system.

20. Tools
Most firms that provide arc flash services utilize specially designed software for electrical system modeling in short circuit and arc flash studies.
Such as SKM Power System Tools

21. Process/Approach to Complete a Study
As-built Documentation
The usual starting point is to gather all existing drawings an Owner has and sort it by location and date. (One-Line Documentation)
Verification
Survey each site and verify one-line documentation. Acquire missing info.
PD types/sizes/settings, cable lengths, Xfmr impedance values
Loading
Load the information into SKM and run Short Circuit, Coordination, Arc Flash

22. Ex: How to Initiate a Study “Large School System”
Herndon HS
Pyramid
Langley HS Pyramid
McLean HS Pyramid
Aldrin ES
Churchill Road ES
Chesterbrook ES
Armstrong ES
Colvin Run ES
Franklin Sherman ES
Clearview ES
Forestville ES
Haycock ES
Dranesville ES
Great Falls ES
Kent Gardens ES
Herndon ES
Spring Hill ES
Timber Lane ES
Hutchison ES
Cooper MS
Longfellow MS
Herndon MS
Langley HS
McLean HS

23. Herndon HS

24. Cluster Analysis Approach
(5) field survey teams composed of (2) people each assigned to various sites within a cluster. All survey is schedule/time dependent.
CLUSTER SITES PYRAMIDS TEAM EST. TIME (mo.)
C A
C B
C C
C D
C E
Following C1-C5
C A/E 5 - 7
C C
C B/D 6 -8

25. 1ST Step - Collect Hard Copy Data
Existing Building Documents -Electrical One-Line Diagrams -Floor Plans -Maintenance Documents

26. 2nd Step - Field Survey

27. Types of Equipment Surveyed

28. Gathering of Information During Survey Process
Protective Device Information
Location, (Room/Panel/What’s it feeding?)
Make, Model, Manufacture
AIC and Trip Plug Rating
Settings

29. 3rd Step - Load the Data Build SKM One-Line Diagrams for each site
Verify accuracy of information
Acquire Utility Company contribution information
Run/Review Short Circuit Calculations
The maximum fault current can be calculated at each electrical buss in the system by knowing the properties of the power sources that will provide the current, and using the impedance values of the circuits that connect the busses
Understanding the “Duty Rating” of the equipment by comparing the available fault current to the rating of the “protective device”

30. Build the Model in the Software

31. Run a Short Circuit Study
Compare Protective Device Ratings Breakers/fuses Against the available 3-phase and SLG Fault currents.

32. Selective Coordination
In order to be assured that all over current protection devices are coordinated, it is necessary to look at the time vs. current characteristic of each device and compare it to the characteristics of any upstream devices.

33. Coordination Example

34. Poor Coordination
Main Breaker Trips, Shutting Down the Entire Switchboard

35. Adjustments to be Made Settings LTPU - Long time pick up
LTD – Long time delay
STPU – Short time Pickup
STD – Short time Delay
I²t – Short time delay bend
INST – Instantaneous
GFPU – Ground Fault Pick up
GFD – Ground Fault Delay
GFI²t – Ground Fault Delay bend

36. Improved Coordination

37. 4th Step - Arc Flash Evaluation
To calculate the available arc flash energy, it is necessary to perform a short circuit study to determine the magnitude of the current that will flow in a fault condition, and also a coordination study to determine the length of time it takes for an Over Current Protection Devices (OCPD) to clear the fault.

38. Arc Flash Analysis

39. Arc Flash Analysis

40. 5th Step – Review Results/Recommendations
Reports are generated based Existing (as is) conditions. Identifies the problem areas with bad coordination and high incident energy categories
Reports are generated based on Recommendations (best scenario) to better coordinate devices and lower arc flash incident energy categories
Begin Training Process

41. ON-SITE ELECTRICAL SAFETY TRAINING
A balance of safety & technical training is essential for continuous improvement
Designed to protect lives, prevent disabling injuries, and prevent damage to your facility & equipment.
Personnel learn about personal safety for working on or around electrical systems
Understand the proper use of materials and procedures for doing electrical work
Hands-on practical instruction that they can immediately apply when they go back to their workplace
Who should be trained? Anyone who works on or around any electrically energized equipment

42. Sample Arc Flash Label

43. Definition Qualified Person
OSHA
One who has received training in and has demonstrated skills and knowledge in the construction and operation of electric equipment and installations and the hazards involved.
NFPA 70E
Skills and knowledge related to the construction and operation of the equipment and has received safety training on the hazards involved.

44. Qualified Person
Are they qualified to be working on live exposed electrical parts?

45. Perception of a Qualified Person
Licensed Electrician = qualified employee
Training Certificates
Years of Experience
“I have never been hurt”

46. Summary Don’t assume that a person is qualified When in doubt, ask!!!!
Their qualifications can affect you, your co-workers, and your company, the facility, etc…
Best Practice: Whenever possible, work on electrical equipment de-energized
Remember, regulations are minimum requirements
Utilize best resources available
Develop a principle directive (Golden Rule!)

47. Multi-Disciplined Team Partial Client List
Quick Facts
Established in 1981
75 employees
4 office locations
Massachusetts
North Carolina
Vermont
Virginia
Multi-Disciplined Team
25 Mechanical
25 Electrical & Controls
15 Instrument Technicians
10 CAD/Admin
Partial Client List
Health Care
Burlington Community Health Ctr.
Fanny Allen Hospital
Fletcher Allen Health Care
Littleton Hospital
University Health Care
University of Vermont, Given Medical
Upper Connecticut Valley Hospital
VA Hospital
BioTech & Pharmaceutical
Astra Zeneca
Baxter Bioscience
Covidien
Genzyme
Johnson & Johnson
LifeNet
Lonza Biologics
Mylan Technologies
Novartis
Pfizer Global R&D
Siemens Medical Solutions
Stryker Biotech
Wyeth
Geographically
Percent of fee revenue
MA Region
VT Region
40%
20%
Mid-Atlantic Region
Services
Percent of fee revenue
Commissioning
Engineering
Systems Integration
30%
35%
Markets
Percent of fee revenue
Life Sciences, Health Care, R&D, Higher Education
Microelectronics
Industrial
70%
15%
Electrical systems design is at the core of our well established MEP firm. Leveraging our knowledge and expertise we can conduct arc flash analysis with precision, and provide recommendations based on our vast experience.
A comprehensive study of the electrical system can provide the Owner the necessary tools to predict possible system failures, as well as the data necessary for safety, maintenance, and future planning.