University of Tennessee, Knoxville TRACE: Tennessee Research and Creative Exchange Doctoral Dissertations Graduate School 12-2020 ARC FLASH IN SINGLE-PHASE ELECTRICAL SYSTEMS John Francis Wade University of Tennessee, Knoxville, [email protected] Follow this and additional works at: https://trace.tennessee.edu/utk_graddiss Part of the Fire Science and Firefighting Commons, and the Power and Energy Commons Recommended Citation Wade, John Francis, "ARC FLASH IN SINGLE-PHASE ELECTRICAL SYSTEMS. " PhD diss., University of Tennessee, 2020. https://trace.tennessee.edu/utk_graddiss/6096 This Dissertation is brought to you for free and open access by the Graduate School at TRACE: Tennessee Research and Creative Exchange. It has been accepted for inclusion in Doctoral Dissertations by an authorized administrator of TRACE: Tennessee Research and Creative Exchange. For more information, please contact [email protected]. To the Graduate Council: I am submitting herewith a dissertation written by John Francis Wade entitled "ARC FLASH IN SINGLE-PHASE ELECTRICAL SYSTEMS." I have examined the final electronic copy of this dissertation for form and content and recommend that it be accepted in partial fulfillment of the requirements for the degree of Doctor of Philosophy, with a major in Electrical Engineering. David J. Icove, Major Professor We have read this dissertation and recommend its acceptance: Mark E. Dean, Benjamin J. Blalock, James Evans Lyne, Vytenis Babrauskas Accepted for the Council: Dixie L. Thompson Vice Provost and Dean of the Graduate School (Original signatures are on file with official studentecor r ds.) ARC FLASH IN SINGLE-PHASE ELECTRICAL SYSTEMS A Dissertation Presented for the Doctor of Philosophy Degree The University of Tennessee, Knoxville John Francis Wade December 2020 Copyright © 2020 by John Francis Wade All rights reserved. ORCID: 0000-0002-6493-5070 ii This work is dedicated to those who have come before and those who encourage and inspire now but most especially to my wife and my family “We stand on the shoulders of giants.” - Isaac Newton iii ACKNOWLEDGEMENTS The author gratefully acknowledges Underwriters Laboratories (UL), Schneider Electric, and the following for invaluable assistance and support: Doctoral Committee Dr. Mark Dean, Dr. Ben Blalock, Dr. Evans Lyne MD, Dr. Vyto Babrauskas and Major Professor - Dr. David Icove Dissertation & Lab Time Grant - Dr. Thomas Chapin, UL Tuition Assistance - BWX Technologies Nuclear Fuel Services Experiment Guidance & Peer Review - Dr. Paul Brazis, UL High Power Lab – facilities, experiment support, lab time donation David Lambrecht - Engineering Manager Jade Kaiser, Ross Soska, and the Schneider Electric team Instrumentation - Eric Kachermeyer, PCB Piezotronics Disclaimer This work explores the history of arc flash investigations and the basis for IEEE 1584 calculations and presents the results of experiments addressing one gap in that Standard. These experiments and the conclusions drawn are the work of the author and do not reflect the work of the IEEE 1584 Working Group nor are they part of the IEEE 1584 Standard. Findings are intended to contribute to the base of knowledge and inspire further exploration. The author assumes no responsibility for any safety-related decisions, or the consequences thereof, based on this work. iv ABSTRACT Arc flash and blast are hazards unique to electrical installations. Such events can start fires, destroy equipment, and severely injure or kill workers. NFPA 70E and IEEE 1584 are defining standards for arc flash hazard analysis used during system design, construction, and maintenance. Both focus on three- phase faults for calculations since three-phase power distribution is predominant in utility and industrial applications. However, discussion of arc flash in single- phase systems prevalent in residential and commercial facilities is excluded. Single-phase faults can also occur in a variety of industrial and utility circumstances. This dissertation explores historic background and treatment of arc flash and foundation phenomena, considers IEEE results as published in the 1584- 2018 standard, and documents the author's work with single-phase arc flash. Experiments were performed at the Schneider Electric facility, High Power Lab #3 in Cedar Rapids, Iowa in June and September 2020. This facility provided a test article; a full suite of voltage, current, and temperature instrumentation; high-speed video recording; and interface for a blast pressure transducer provided by the principal investigator. Test plan development used a template provided by Schneider. Scenarios were peer-reviewed in advance. Experimental work revealed very low levels of heat released for most single-phase arc fault events at 434 volts and below though there was still blast, flash, and splatter of molten wire residue. In contrast, single-phase events at 460 v volts and above produced sustained arcs, orders of magnitude more heat, and dangerously high levels of blast pressure. Conclusions drawn are that low energy single-phase systems may be at low or very low risk of yielding arc flash burn-related injuries resulting from accidental short circuits. However, single-phase faults in systems with open circuit voltage at 460 volts or greater can produce significant levels of incident heat energy, flash, and blast pressure even at moderate levels of available fault current. vi TABLE OF CONTENTS Chapter One : Introduction .................................................................................... 1 Chapter Two : Literature Review - Arc Flash ........................................................ 5 Early Work on Arcing Faults .............................................................................. 6 Initial Consideration of Arc Flash ....................................................................... 9 Development of Basis for Protective Equipment Selection.............................. 10 Recent Work ................................................................................................... 12 Chapter Three : Analyses of Selected Works ..................................................... 16 Lee’s Initial Work ............................................................................................. 17 Stanback ......................................................................................................... 18 Doughty, Neal, Bingham, Floyd ....................................................................... 21 ASTM .............................................................................................................. 22 NFPA 70E ....................................................................................................... 22 Stokes, Oppenlander, and Sweeting ............................................................... 23 IEEE 1584 ....................................................................................................... 25 Smoak and Keeth ............................................................................................ 27 Gaps in Arc Flash Research for Single-Phase Systems ................................. 29 Chapter Four : Literature Review - Electric Arcs Behavior and Effects .............. 31 Physics of Fuse-Wire Initiated Arcs ................................................................. 32 Time to Onset .............................................................................................. 32 Contribution of Metallic Vapor ...................................................................... 34 Migration of the Arc ...................................................................................... 35 Heat and Burns ............................................................................................... 36 Heat Transport ............................................................................................. 36 Structure of Human Skin Related to Burns .................................................. 37 Skin Burn Classification ............................................................................... 37 Skin Burn Models ......................................................................................... 38 Arc Blast .......................................................................................................... 39 Hearing Damage .......................................................................................... 40 Blunt Force Trauma ..................................................................................... 41 Arc Flash Light Emission ................................................................................. 41 Vision Damage ............................................................................................ 43 Chapter Five : Representative Case Histories of Arc Flash Injuries.................... 45 Case: Chew et al. v. American Greetings Corp. .............................................. 47 Case: Khosh vs. Staples Construction Inc. ..................................................... 50 vii Case: Gerasi v. Gilbane Building Co. .............................................................. 52 Case: Arc Flash Accident - LANL TA-53 ......................................................... 55 Case: Electrical Arc Injury - Stanford Linear Accelerator Center ..................... 58 Case: Arc Flash - PM of Vacuum Circuit Breakers .......................................... 61 Case: Arc Flash - Locked Out 3.3-kV Fused Contactor................................... 63 Chapter Six : Experimental Materials