importance of arc flash analysis (“arc flash loss prevention”)

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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. - PowerPoint PPT Presentation

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Page 1: Importance of Arc Flash Analysis (“Arc Flash Loss Prevention”)
Page 2: Importance of Arc Flash Analysis (“Arc Flash Loss Prevention”)

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

Page 3: Importance of Arc Flash Analysis (“Arc Flash Loss Prevention”)

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

Page 4: Importance of Arc Flash Analysis (“Arc Flash Loss Prevention”)

Electrical Hazards Consist of:

Electric Shock

Arc Flash

Arc Blast

Other Hazards

Page 5: Importance of Arc Flash Analysis (“Arc Flash Loss Prevention”)

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.

Page 6: Importance of Arc Flash Analysis (“Arc Flash Loss Prevention”)

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.

Page 7: Importance of Arc Flash Analysis (“Arc Flash Loss Prevention”)

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

Page 8: Importance of Arc Flash Analysis (“Arc Flash Loss Prevention”)

Safe Work Practices

OSHA 1910.333

• 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

Page 9: Importance of Arc Flash Analysis (“Arc Flash Loss Prevention”)

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

Page 10: Importance of Arc Flash Analysis (“Arc Flash Loss Prevention”)

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

Page 11: Importance of Arc Flash Analysis (“Arc Flash Loss Prevention”)

Approach Boundary to Live Parts

Limited (42 in)

Restricted (12 in)

Prohibited (1 in)

Based on system voltage = 480VNFPA 70E, Annex C, Figure C.1.2.4

Page 12: Importance of Arc Flash Analysis (“Arc Flash Loss Prevention”)

Flash Protection Boundaries (FPB)

Using NFPA 70E, the methods to determine FPB

• Defaults (i.e. tables)

• Perform Analysis that uses Calculation Methods

Page 13: Importance of Arc Flash Analysis (“Arc Flash Loss Prevention”)

Levels of Exposure

Page 14: Importance of Arc Flash Analysis (“Arc Flash Loss Prevention”)

Personal Protective Equipment (PPE)

Page 15: Importance of Arc Flash Analysis (“Arc Flash Loss Prevention”)

PPE

Designed to protect specific areas of the body

• Eye Protection

• Neck, Face, Head, Chin

• Arm & Hand Protection

• Body Protection

• Leg & Foot Protection

Page 16: Importance of Arc Flash Analysis (“Arc Flash Loss Prevention”)

PPE - Gloves

Voltage rated gloves are REQUIRED for all voltage testing above 50 volts

Page 17: Importance of Arc Flash Analysis (“Arc Flash Loss Prevention”)

OSHA/NFPA 70EGeneral Industry Requirements

OSHA 1910.355(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

Page 18: Importance of Arc Flash Analysis (“Arc Flash Loss Prevention”)

OSHA Fines

For non-compliance, OSHA may audit a facility and issue fines

Most recently: U.S. Postal Service

$420,000 (pending) – single facility

Page 19: Importance of Arc Flash Analysis (“Arc Flash Loss Prevention”)

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.

Page 20: Importance of Arc Flash Analysis (“Arc Flash Loss Prevention”)

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

Page 21: Importance of Arc Flash Analysis (“Arc Flash Loss Prevention”)

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

Page 22: Importance of Arc Flash Analysis (“Arc Flash Loss Prevention”)

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

Herndon HS

Page 23: Importance of Arc Flash Analysis (“Arc Flash Loss Prevention”)

Herndon HS

Page 24: Importance of Arc Flash Analysis (“Arc Flash Loss Prevention”)

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.)

C1 22 3 A 8 - 12

C2 28 3 B 10 - 12

C3 27 3 C 9 - 11

C4 28 3 D 10 - 12

C5 22 3 E 8 - 10

Following C1-C5

C6 22 3 A/E 5 - 7

C7 25 3 C 9 - 11

C8 25 3 B/D 6 -8

Page 25: Importance of Arc Flash Analysis (“Arc Flash Loss Prevention”)

1ST Step - Collect Hard Copy Data

Existing Building Documents

-Electrical One-Line Diagrams

-Floor Plans

-Maintenance Documents

Page 26: Importance of Arc Flash Analysis (“Arc Flash Loss Prevention”)

2nd Step - Field Survey

Page 27: Importance of Arc Flash Analysis (“Arc Flash Loss Prevention”)

Types of Equipment Surveyed

Page 28: Importance of Arc Flash Analysis (“Arc Flash Loss Prevention”)

Gathering of InformationDuring Survey Process

Protective Device Information

• Location, (Room/Panel/What’s it feeding?)

• Make, Model, Manufacture

• AIC and Trip Plug Rating

• Settings

Page 29: Importance of Arc Flash Analysis (“Arc Flash Loss Prevention”)

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”

Page 30: Importance of Arc Flash Analysis (“Arc Flash Loss Prevention”)

Build the Model in the SoftwareDominion Power

13800.0 VSC Contribution 3P 10000.0 AmpsSC Contribution SLG 1000.0 AmpsX/R 3P 8.000X/R SLG 8.000

C-UTILITY FEEDER2 -#500, 120ft

S

P T-UTILTIY FEEDER300.0 kVA13800/480V5.0 %Z

C-SWITCH BOARD-MAIN1 -#500, 30ft

PD-SWITCH BOARD-MAINSensor/Trip 800A/400A

SWITCH BOARD480.0 V

PD-PP1Sensor/Trip 250A/200A

C-PP11 -#2/0, 56ft

PD-PP1-MAINSensor/Trip 150A

PP1480.0 V

PD-AC/1Sensor/Trip 250A/100A

C-AC/1-DISC1 -#4, 20ft

PD-AC/1-DISCSensor/Trip 80A

AC/1-DISC480.0 V

C-AC/11 -#4, 20ft

M-AC/1 60.0 hp

PD-LPSensor/Trip 400A/300A

C-T-LP1 -#350, 40ft

PD-LP-MAINSensor/Trip 125A

C-LP1 -#2, 10ft

LP208.0 V

S

P T-LP45.0 kVA480/208V5.0 %Z

Page 31: Importance of Arc Flash Analysis (“Arc Flash Loss Prevention”)

Run a Short Circuit Study

Compare

Protective Device Ratings Breakers/fuses Against the available

3-phase and SLG Fault currents.

Available Fault Current

Device Rating

Dominion Power3P Contribution 10000.0 AmpsSLG Cont ribut ion 1000.0 AmpsX/R 3P 8.000X/R SLG 8.000

C-UTILITY FEEDER

S

P T-UTILTIY FEEDER300.0 kVA13800/480V5.0 % Z

C-SWITCH BOARD-MAIN

PD-SWITCH BOARD-MAINRating 65kA

SWITCH BOARD7238 Amps 3P7034 Amps SLGPD-PP1

Rating 65kA

C-PP1

PD-PP1-MAINRating 25kA

PP16472 Amps 3P5916 Amps SLG

PD-AC/1Rating 65kA

C-AC/1-DISC

PD-AC/1-DISCRating 200kA

AC/1-DISC6731 Amps 3P6183 Amps SLG

C-AC/1

M-AC/160.0 hp72.4A

PD-LPRating 65kA

C-T-LP

PD-LP-MAINRating 30kA

C-LP

LP2111 Amps 3P2177 Amps SLG

S

P T-LP45.0 kVA480/208V5.0 % Z

Device Rating

Device Rating

Device Rating

Device Rating

Device Rating

Device Rating

Available Fault Current

Available Fault Current

Available Fault Current

Page 32: Importance of Arc Flash Analysis (“Arc Flash Loss Prevention”)

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.

Page 33: Importance of Arc Flash Analysis (“Arc Flash Loss Prevention”)

Coordination Example Dominion Power

13800.0 VSC Contribution 3P 10000.0 AmpsSC Contribution SLG 1000.0 AmpsX/R 3P 8.000X/R SLG 8.000

C-UTILITY FEEDER2 -#500, 120ft

S

P T-UTILTIY FEEDER300.0 kVA13800/480V5.0 %Z

C-SWITCH BOARD-MAIN1 -#500, 30ft

PD-SWITCH BOARD-MAINSensor/Trip 800A/400A

SWITCH BOARD480.0 V

PD-PP1Sensor/Trip 250A/200A

C-PP11 -#2/0, 56ft

PD-PP1-MAINSensor/Trip 150A

PP1480.0 V

PD-AC/1Sensor/Trip 250A/100A

C-AC/1-DISC1 -#4, 20ft

PD-AC/1-DISCSensor/Trip 80A

AC/1-DISC480.0 V

C-AC/11 -#4, 20ft

M-AC/1 60.0 hp

PD-LPSensor/Trip 400A/300A

C-T-LP1 -#350, 40ft

PD-LP-MAINSensor/Trip 125A

C-LP1 -#2, 10ft

LP208.0 V

S

P T-LP45.0 kVA480/208V5.0 %Z

0.5 1 10 100 1K 10K 100K0.01

0.10

1

10

100

1000

CURRENT IN AMPERES

tcc1.tcc Ref. Voltage: 480V Current in Amps x 1

TIM

E IN

SE

CO

ND

S

PD-PP1-MAINSQUARE D KA KA Trip 70.0 ASettings Phase Thermal Curve INST LO (350A)

PD-SWITCH BOARD-MAINSQUARE D DS/DSL, Digitrip RMS 510/610/810/PowerLogic 810D DS-206E Trip 600.0 APlug 600.0 ASettings Phase LTPU (0.5-1.0 x P) 1 (600A) LTD (2-24 Sec.) 24 STPU (2-10 x LTPU) 2 (1200A) STD (0.1-0.5 Sec.) 0.1 (I^2t Out) INST (2-12 x P) M1 (4800A)

PD-PP1SQUARE D DS/DSL, Digitrip RMS 510/610/810/PowerLogic 810D DS-206E Trip 600.0 APlug 400.0 ASettings Phase LTPU (0.5-1.0 x P) 0.8 (320A) LTD (2-24 Sec.) 2 STPU (2-10 x LTPU) 5 (1600A) STD (0.1-0.5 Sec.) 0.4 (I^2t Out) INST (2-12 x P) 6 (2400A)

PD-PP1-MAINSQUARE D KA KA Trip 70.0 ASettings Phase Thermal Curve INST LO (350A)

PD-SWITCH BOARD-MAINSQUARE D DS/DSL, Digitrip RMS 510/610/810/PowerLogic 810D DS-206E Trip 600.0 APlug 600.0 ASettings Phase LTPU (0.5-1.0 x P) 1 (600A) LTD (2-24 Sec.) 24 STPU (2-10 x LTPU) 2 (1200A) STD (0.1-0.5 Sec.) 0.1 (I^2t Out) INST (2-12 x P) M1 (4800A)

PD-PP1SQUARE D DS/DSL, Digitrip RMS 510/610/810/PowerLogic 810D DS-206E Trip 600.0 APlug 400.0 ASettings Phase LTPU (0.5-1.0 x P) 0.8 (320A) LTD (2-24 Sec.) 2 STPU (2-10 x LTPU) 5 (1600A) STD (0.1-0.5 Sec.) 0.4 (I^2t Out) INST (2-12 x P) 6 (2400A)

Page 34: Importance of Arc Flash Analysis (“Arc Flash Loss Prevention”)

Poor CoordinationDominion Power

13800.0 VSC Contribution 3P 10000.0 AmpsSC Contribution SLG 1000.0 AmpsX/R 3P 8.000X/R SLG 8.000

C-UTILITY FEEDER2 -#500, 120ft

S

P T-UTILTIY FEEDER300.0 kVA13800/480V5.0 %Z

C-SWITCH BOARD-MAIN1 -#500, 30ft

PD-SWITCH BOARD-MAINSensor/Trip 800A/400A

SWITCH BOARD480.0 V

PD-PP1Sensor/Trip 250A/200A

C-PP11 -#2/0, 56ft

PD-PP1-MAINSensor/Trip 150A

PP1480.0 V

PD-AC/1Sensor/Trip 250A/100A

C-AC/1-DISC1 -#4, 20ft

PD-AC/1-DISCSensor/Trip 80A

AC/1-DISC480.0 V

C-AC/11 -#4, 20ft

M-AC/1 60.0 hp

PD-LPSensor/Trip 400A/300A

C-T-LP1 -#350, 40ft

PD-LP-MAINSensor/Trip 125A

C-LP1 -#2, 10ft

LP208.0 V

S

P T-LP45.0 kVA480/208V5.0 %Z

0.5 1 10 100 1K 10K 100K0.01

0.10

1

10

100

1000

CURRENT IN AMPERES

tcc1.tcc Ref. Voltage: 480V Current in Amps x 1

TIM

E IN

SE

CO

ND

S

PD-PP1-MAINSQUARE D KA KA Trip 70.0 ASettings Phase Thermal Curve INST LO (350A)

PD-SWITCH BOARD-MAINSQUARE D DS/DSL, Digitrip RMS 510/610/810/PowerLogic 810D DS-206E Trip 600.0 APlug 600.0 ASettings Phase LTPU (0.5-1.0 x P) 1 (600A) LTD (2-24 Sec.) 24 STPU (2-10 x LTPU) 2 (1200A) STD (0.1-0.5 Sec.) 0.1 (I^2t Out) INST (2-12 x P) M1 (4800A)

PD-PP1SQUARE D DS/DSL, Digitrip RMS 510/610/810/PowerLogic 810D DS-206E Trip 600.0 APlug 400.0 ASettings Phase LTPU (0.5-1.0 x P) 0.8 (320A) LTD (2-24 Sec.) 2 STPU (2-10 x LTPU) 5 (1600A) STD (0.1-0.5 Sec.) 0.4 (I^2t Out) INST (2-12 x P) 6 (2400A)

PD-PP1-MAINSQUARE D KA KA Trip 70.0 ASettings Phase Thermal Curve INST LO (350A)

PD-SWITCH BOARD-MAINSQUARE D DS/DSL, Digitrip RMS 510/610/810/PowerLogic 810D DS-206E Trip 600.0 APlug 600.0 ASettings Phase LTPU (0.5-1.0 x P) 1 (600A) LTD (2-24 Sec.) 24 STPU (2-10 x LTPU) 2 (1200A) STD (0.1-0.5 Sec.) 0.1 (I^2t Out) INST (2-12 x P) M1 (4800A)

PD-PP1SQUARE D DS/DSL, Digitrip RMS 510/610/810/PowerLogic 810D DS-206E Trip 600.0 APlug 400.0 ASettings Phase LTPU (0.5-1.0 x P) 0.8 (320A) LTD (2-24 Sec.) 2 STPU (2-10 x LTPU) 5 (1600A) STD (0.1-0.5 Sec.) 0.4 (I^2t Out) INST (2-12 x P) 6 (2400A)

Main Breaker Trips, Shutting Down the Entire Switchboard

Page 35: Importance of Arc Flash Analysis (“Arc Flash Loss Prevention”)

Adjustments to be Made

0.5 1 10 100 1K 10K 100K0.01

0.10

1

10

100

1000

CURRENT IN AMPERES

tcc1.tcc Ref. Voltage: 480V Current in Amps x 1

TIM

E IN

SE

CO

ND

S

PD-PP1-MAINSQUARE D KA KA Trip 70.0 ASettings Phase Thermal Curve INST LO (350A)

PD-SWITCH BOARD-MAINSQUARE D DS/DSL, Digitrip RMS 510/610/810/PowerLogic 810D DS-206E Trip 600.0 APlug 600.0 ASettings Phase LTPU (0.5-1.0 x P) 1 (600A) LTD (2-24 Sec.) 24 STPU (2-10 x LTPU) 2 (1200A) STD (0.1-0.5 Sec.) 0.1 (I^2t Out) INST (2-12 x P) M1 (4800A)

PD-PP1SQUARE D DS/DSL, Digitrip RMS 510/610/810/PowerLogic 810D DS-206E Trip 600.0 APlug 400.0 ASettings Phase LTPU (0.5-1.0 x P) 0.8 (320A) LTD (2-24 Sec.) 2 STPU (2-10 x LTPU) 5 (1600A) STD (0.1-0.5 Sec.) 0.4 (I^2t Out) INST (2-12 x P) 6 (2400A)

PD-PP1-MAINSQUARE D KA KA Trip 70.0 ASettings Phase Thermal Curve INST LO (350A)

PD-SWITCH BOARD-MAINSQUARE D DS/DSL, Digitrip RMS 510/610/810/PowerLogic 810D DS-206E Trip 600.0 APlug 600.0 ASettings Phase LTPU (0.5-1.0 x P) 1 (600A) LTD (2-24 Sec.) 24 STPU (2-10 x LTPU) 2 (1200A) STD (0.1-0.5 Sec.) 0.1 (I^2t Out) INST (2-12 x P) M1 (4800A)

PD-PP1SQUARE D DS/DSL, Digitrip RMS 510/610/810/PowerLogic 810D DS-206E Trip 600.0 APlug 400.0 ASettings Phase LTPU (0.5-1.0 x P) 0.8 (320A) LTD (2-24 Sec.) 2 STPU (2-10 x LTPU) 5 (1600A) STD (0.1-0.5 Sec.) 0.4 (I^2t Out) INST (2-12 x P) 6 (2400A)

These devices are not coordinated. By adjusting the settings on each devices we can improve coordination..

These devices are not coordinated. By adjusting the settings on each devices we can improve coordination..

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

Page 36: Importance of Arc Flash Analysis (“Arc Flash Loss Prevention”)

Improved Coordination

0.5 1 10 100 1K 10K 100K0.01

0.10

1

10

100

1000

CURRENT IN AMPERES

tcc1.tcc Ref. Voltage: 480V Current in Amps x 1

TIM

E IN

SE

CO

ND

S

PD-PP1-MAINSQUARE D KA KA Trip 70.0 ASettings Phase Thermal Curve INST LO (350A)

PD-PP1SQUARE D DS/DSL, Digitrip RMS 510/610/810/PowerLogic 810D DS-206E Trip 600.0 APlug 400.0 ASettings Phase LTPU (0.5-1.0 x P) 0.8 (320A) LTD (2-24 Sec.) 7 STPU (2-10 x LTPU) 2 (640A) STD (0.1-0.5 Sec.) 0.1 (I^2t Out) INST (2-12 x P) 2 (800A)

PD-SWITCH BOARD-MAINSQUARE D DS/DSL, Digitrip RMS 510/610/810/PowerLogic 810D DS-206E Trip 600.0 APlug 600.0 ASettings Phase LTPU (0.5-1.0 x P) 1 (600A) LTD (2-24 Sec.) 7 STPU (2-10 x LTPU) 2 (1200A) STD (0.1-0.5 Sec.) 0.2 (I^2t Out) INST (2-12 x P) 5 (3000A)

PD-PP1-MAINSQUARE D KA KA Trip 70.0 ASettings Phase Thermal Curve INST LO (350A)

PD-PP1SQUARE D DS/DSL, Digitrip RMS 510/610/810/PowerLogic 810D DS-206E Trip 600.0 APlug 400.0 ASettings Phase LTPU (0.5-1.0 x P) 0.8 (320A) LTD (2-24 Sec.) 7 STPU (2-10 x LTPU) 2 (640A) STD (0.1-0.5 Sec.) 0.1 (I^2t Out) INST (2-12 x P) 2 (800A)

PD-SWITCH BOARD-MAINSQUARE D DS/DSL, Digitrip RMS 510/610/810/PowerLogic 810D DS-206E Trip 600.0 APlug 600.0 ASettings Phase LTPU (0.5-1.0 x P) 1 (600A) LTD (2-24 Sec.) 7 STPU (2-10 x LTPU) 2 (1200A) STD (0.1-0.5 Sec.) 0.2 (I^2t Out) INST (2-12 x P) 5 (3000A)

These devices are now coordinated. PD-PP1 will know trip before the Switchboard Main..

These devices are now coordinated. PD-PP1 will know trip before the Switchboard Main..

Dominion Power13800.0 VSC Contribution 3P 10000.0 AmpsSC Contribution SLG 1000.0 AmpsX/R 3P 8.000X/R SLG 8.000

C-UTILITY FEEDER2 -#500, 120ft

S

P T-UTILTIY FEEDER300.0 kVA13800/480V5.0 %Z

C-SWITCH BOARD-MAIN1 -#500, 30ft

PD-SWITCH BOARD-MAINSensor/Trip 800A/400A

SWITCH BOARD480.0 V

PD-PP1Sensor/Trip 250A/200A

C-PP11 -#2/0, 56ft

PD-PP1-MAINSensor/Trip 150A

PP1480.0 V

PD-AC/1Sensor/Trip 250A/100A

C-AC/1-DISC1 -#4, 20ft

PD-AC/1-DISCSensor/Trip 80A

AC/1-DISC480.0 V

C-AC/11 -#4, 20ft

M-AC/1 60.0 hp

PD-LPSensor/Trip 400A/300A

C-T-LP1 -#350, 40ft

PD-LP-MAINSensor/Trip 125A

C-LP1 -#2, 10ft

LP208.0 V

S

P T-LP45.0 kVA480/208V5.0 %Z

Page 37: Importance of Arc Flash Analysis (“Arc Flash Loss Prevention”)

4th Step - Arc Flash Evaluation

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.

Page 38: Importance of Arc Flash Analysis (“Arc Flash Loss Prevention”)

Arc Flash AnalysisDominion Power

C-UTILITY FEEDER

S

P T-UTILTIY FEEDER

C-SWITCH BOARD-MAIN

PD-SWITCH BOARD-MAIN

SWITCH BOARDEnergy 23.9 Cal/cm^2@ 18 inchesPPE Class 3

PD-PP1

C-PP1

PD-PP1-MAIN

PP1Energy 0.2 Cal/cm^2@ 18 inchesPPE Class 0

PD-AC/1

C-AC/1-DISC

PD-AC/1-DISC

AC/1-DISCEnergy 0.2 Cal/cm^2@ 18 inchesPPE Class 0

C-AC/1

M-AC/1

PD-LP

C-T-LP

PD-LP-MAIN

C-LP

LPEnergy 0.1 Cal/cm^2@ 18 inchesPPE Class 0

S

P T-LP

Page 39: Importance of Arc Flash Analysis (“Arc Flash Loss Prevention”)

Arc Flash Analysis

Dominion Power

C-UTILITY FEEDER

S

P T-UTILTIY FEEDER

C-SWITCH BOARD-MAIN

PD-SWITCH BOARD-MAIN

SWITCH BOARDEnergy 23.9 Cal/cm^2@ 18 inchesPPE Class 3

PD-PP1

C-PP1

PD-PP1-MAIN

PP1Energy 0.2 Cal/cm^2@ 18 inchesPPE Class 0

PD-AC/1

C-AC/1-DISC

PD-AC/1-DISC

AC/1-DISCEnergy 0.2 Cal/cm^2@ 18 inchesPPE Class 0

C-AC/1

M-AC/1

PD-LP

C-T-LP

PD-LP-MAIN

C-LP

LPEnergy 0.1 Cal/cm^2@ 18 inchesPPE Class 0

S

P T-LP

0.5 1 10 100 1K 10K 100K0.01

0.10

1

10

100

1000

CURRENT IN AMPERES

tcc1.tcc Ref. Voltage: 480V Current in Amps x 1

TIM

E IN

SE

CO

ND

S

PD-PP1SQUARE D DS/DSL, Digitrip RMS 510/610/810/PowerLogic 810D DS-206E Trip 600.0 APlug 400.0 ASettings Phase LTPU (0.5-1.0 x P) 0.8 (320A) LTD (2-24 Sec.) 2 STPU (2-10 x LTPU) 3 (960A) STD (0.1-0.5 Sec.) 0.4 (I^2t Out) INST (2-12 x P) 4 (1600A)

PD-PP1-MAINSQUARE D KA KA Trip 70.0 ASettings Phase Thermal Curve INST LO (350A)

PD-SWITCH BOARD-MAINSQUARE D DS/DSL, Digitrip RMS 510/610/810/PowerLogic 810D DS-206E Trip 800.0 APlug 800.0 ASettings Phase LTPU (0.5-1.0 x P) 1 (800A) LTD (2-24 Sec.) 24 STPU (2-10 x LTPU) S1 (6400A) STD (0.1-0.5 Sec.) 0.1 (I^2t Out) INST (2-12 x P) M2 (10160A)

PD-PP1SQUARE D DS/DSL, Digitrip RMS 510/610/810/PowerLogic 810D DS-206E Trip 600.0 APlug 400.0 ASettings Phase LTPU (0.5-1.0 x P) 0.8 (320A) LTD (2-24 Sec.) 2 STPU (2-10 x LTPU) 3 (960A) STD (0.1-0.5 Sec.) 0.4 (I^2t Out) INST (2-12 x P) 4 (1600A)

PD-PP1-MAINSQUARE D KA KA Trip 70.0 ASettings Phase Thermal Curve INST LO (350A)

PD-SWITCH BOARD-MAINSQUARE D DS/DSL, Digitrip RMS 510/610/810/PowerLogic 810D DS-206E Trip 800.0 APlug 800.0 ASettings Phase LTPU (0.5-1.0 x P) 1 (800A) LTD (2-24 Sec.) 24 STPU (2-10 x LTPU) S1 (6400A) STD (0.1-0.5 Sec.) 0.1 (I^2t Out) INST (2-12 x P) M2 (10160A)

The Switchboard Main breaker clear the fault in 60 seconds.

Arc Flash Current

The Switchboard Main breaker clear the fault in 60 seconds.

Arc Flash Current

Page 40: Importance of Arc Flash Analysis (“Arc Flash Loss Prevention”)

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

Page 41: Importance of Arc Flash Analysis (“Arc Flash Loss Prevention”)

ON-SITE ELECTRICALSAFETY 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

Page 42: Importance of Arc Flash Analysis (“Arc Flash Loss Prevention”)

Sample Arc Flash Label

Page 43: Importance of Arc Flash Analysis (“Arc Flash Loss Prevention”)

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.

Page 44: Importance of Arc Flash Analysis (“Arc Flash Loss Prevention”)

Qualified Person

Are they qualified to be working on live exposed electrical parts?

Page 45: Importance of Arc Flash Analysis (“Arc Flash Loss Prevention”)

Perception of a Qualified Person

Licensed Electrician = qualified employee

Training Certificates

Years of Experience

“I have never been hurt”

Page 46: Importance of Arc Flash Analysis (“Arc Flash Loss Prevention”)

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!)

Page 47: Importance of Arc Flash Analysis (“Arc Flash Loss Prevention”)

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.

Quick FactsEstablished in 198175 employees4 office locations Massachusetts North Carolina Vermont Virginia

Multi-Disciplined Team 25 Mechanical 25 Electrical & Controls 15 Instrument Technicians 10 CAD/Admin

Partial Client ListHealth CareBurlington Community Health Ctr.Fanny Allen HospitalFletcher Allen Health CareLittleton HospitalUniversity Health CareUniversity of Vermont, Given MedicalUpper Connecticut Valley HospitalVA Hospital

BioTech & PharmaceuticalAstra ZenecaBaxter BioscienceCovidienGenzymeJohnson & JohnsonLifeNet Lonza BiologicsMylan TechnologiesNovartisPfizer Global R&DSiemens Medical SolutionsStryker BiotechWyeth

Geographically

Percent of fee revenueMA RegionVT Region

40%

40%20%

Mid-Atlantic Region

ServicesPercent of fee revenue

CommissioningEngineering

Systems Integration

30%35%

35%

MarketsPercent of fee revenue

Life Sciences, Health Care, R&D, Higher Education

Microelectronics

Industrial

70% 15%

15%

Page 48: Importance of Arc Flash Analysis (“Arc Flash Loss Prevention”)