Presentation Transcript
Arc Flash Energy & Protection : Arc Flash Energy & Protection Presented by EWB Engineering
(Electrical Engineers)
Objective : Objective To Understand
What is An Arc Flash
Why OSHA Is Addressing This Issue
New Requirements In NEC & NFPA 70E
Impact to Industry
Steps in Performing an Arc Flash Analysis
How to Select Required Protective Clothing
Slide3 : Arc Flash Event Every Day An Electrician Is Severely Injured by an Arc Flash Event
What Is An Arc Flash : What Is An Arc Flash Arc Resistant Switchgear Undergoing Test For an Arcing Fault An Arc Flash is a Sudden Release of Heat and Energy Caused By An Electric Arc
Recent Changes : Recent Changes Attention to Personnel Protection (PPE)
Recognition of Unsafe Work Practices
Impact to Business and Medical Costs
Changes to NFPA 70E & NEC
IEEE Standard for Arc Flash Analysis
Requirements of OSHA 1910, Subpart S
What Does OSHA Say? : What Does OSHA Say? 29 CFR 1910.333
Live electrical parts that an employee may be exposed shall be de-energized unless additional or greater hazards are introduced.
29 CFR 1910.335
Employees working in areas where potential electrical hazards exist shall be provided with and shall use personal protective equipment.
What Does NFPA 70E Say? : What Does NFPA 70E Say? NFPA 70E, Part II, 2-1.3.3
“A flash hazard analysis shall be done before a person approaches any exposed electrical conductor or circuit part that has not been placed in an electrically safe work condition.”
What Does National Electric Code (NEC) Say? : What Does National Electric Code (NEC) Say? NEC 110.16
States Equipment must be marked to warn qualified persons of potential electrical arc flash hazards.
Results of Arc Flash Analysis : Results of Arc Flash Analysis Flash Protection Boundary
Incident Arc Energy
Hazard Level for PPE
Arc Flash Principles : Arc Flash Principles Radiated Energy From Flash
Radiated Energy Function of
Arc Power
Distance From Arc
Time to Extinguish Arc
Arc Power Function of
Arc Voltage & Arc Current
Arc Voltage Function of
Arc Gap
Incident Arc Energy : Incident Arc Energy The amount of energy impressed on a surface, a certain distance from the source, generated during an arc event.
Arc Flash Boundary : Arc Flash Boundary
A distance from exposed live parts within which a person could receive a second degree burn.
Determine PPE Hazard Level : Determine PPE Hazard Level Category Cal / cm2 FR Clothing
0 1.2 Untreated Cotton
1 5 FR Shirt & FR Pants
2 8 Cotton Underwear + FR Shirt & FR Pants
3 25 Cotton Underwear + FR Shirt & FR Pants + FR Coverall
4 40 Cotton Underwear + FR Shirt & FR Pants +
Double Layer Switching Coat & Pants
Calculation Methods : Calculation Methods IEEE 1584
IEEE Method Preferred
NFPA 70E Tables
Can Be Used if Calculations Not Available
Limited Range of Fault Currents and Protective Device Characteristics
PPE Clothing Requirements : PPE Clothing Requirements Employees Required to Wear Flame Resistant (FR) Clothing – PPE
The Required Level of Clothing and Personal Protection Depends on the
Calculated Incident Arc Energy
For
The Specific Task
Arc Flash PPE Categories : Arc Flash PPE Categories Category 0
Untreated Cotton (Long Sleeve)
Untreated Cotton Pants (Long)
Voltage Rated Gloves
Safety Glasses
Hard Hat Category 1
FR Long Sleeve Shirt
Untreated Cotton Pants (Long)
FR Pants (Long)
Safety Glasses
Voltage Rated Gloves
Hard Hat
Arc Flash PPE Categories : Arc Flash PPE Categories Category 2
Untreated Cotton T-Shirt
Untreated Cotton Shirt (Long Sleeve)
FR Shirt (Long Sleeve)
Untreated Cotton Pants (Long)
FR Pants (Long)
Safety Glasses
Voltage Rated Gloves
Hard Hat
Double Layer Bee Keepers Hood
Arc Flash PPE Categories : Arc Flash PPE Categories Category 3
Untreated Cotton T-Shirt
Untreated Cotton Shirt (Long Sleeve)
FR Shirt (Long Sleeve)
Untreated Cotton Pants (Long)
FR Pants (Long)
Voltage Rated Gloves
Safety Glasses
FR Hard Hat Liner
Hard Hat
Double Layer Bee Keepers Hood
Hearing Protection
Arc Flash PPE Categories : Arc Flash PPE Categories Category 4
Untreated Cotton T-Shirt
Untreated Cotton Shirt (Long Sleeve)
FR Shirt (Long Sleeve)
Untreated Cotton Pants (Long)
FR Pants (Long)
FR Coveralls
Voltage Rated Gloves
Safety Glasses
FR Hard Hat Liner
Hard Hat
Double Layer Bee Keepers Hood
Hearing Protection
Conclusions : Conclusions OSHA & NFPA 70E Require An Arc Flash Hazard Analysis For Proper PPE
New Requirement in NEC States That Arc Flash Warning Labels Be Placed on Electrical Panels and Switchboards.
IEEE 1584 is Preferred Method for Determining Arc Flash Incident Energy & Arc Flash Boundaries.
Fault Study
Coordination Study
Determine Incident Arc Energy
Catch the
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