Arc Hazard Assessment for DC Applications in the Transit Industry
|
|
- Barnaby Price
- 5 years ago
- Views:
Transcription
1 Arc Hazard Assessment for DC Applications in the Transit Industry Kenneth S.Y. Cheng Kinectrics Inc. Toronto, Canada Stephen L. Cress Kinectrics Inc. Toronto, Canada Donald J. Minini Excalibur Associates, Inc. Connecticut, United States I TRODUCTIO During accidental faults on electrical power systems, workers may be exposed to hazards from electrical arcs. A prime concern is the exposure of workers to the intense radiated component of the arc energy, which has the potential to cause skin burns. In the United States of America, it has been reported that approximately 8% of electrical injuries are due to burns from exposure to radiant and convective energy from electrical arcs [1]. Further studies show that between 1 and 15 workers are hospitalized everyday due to burns caused by arc flash [2]. Safety programs including arc hazard analysis are dedicated to protecting workers from burns caused by electric arcs. Arc hazard analysis programs have been implemented by electric utilities and industries across North America and similar programs have been established in some public transportation organizations. These programs are conducted to select appropriate Personal Protective Equipment (PPE) for employees to limit burns to levels that are considered curable. Safety regulations such as Occupational Safety and Health Administration (OSHA) states clearly that it is the employers responsibilities to ensure that the employees are adequately protected (OSHA l,6,iii states that the employer shall ensure that each employee who is exposed to the hazards of flames or electric arcs does not wear clothing that could increase the extent of injury.). In the past few years, several corporations had been heavily penalized for their negligence. One of the more severe penalties charged by OSHA can be found in reference [3]. Assessment of thermal radiation from arcs is required for both Alternating Current (AC) and Direct Current (DC) electrical systems. A significant amount of testing and computational method development has been conducted related to the incident radiated energy that can be produced from AC faults [5], [6], [7]. This has resulted in a number of useful tools for assessing AC arc hazards in various industrial and utility work situations related to AC power systems (e.g. NFPA 7E, IEEE 1584, ArcPro TM ). There has been, however, a lack of test data and scientific algorithm development for the purpose of assessing DC arc hazard analysis. DC arc exposure might occur at locations with sizable battery banks and rectifiers such as in power plants or in the transportation or railway sectors. To-date, there is no single set of equations that can be used to evaluate all DC arc hazard situations. Several reviews of possible methodologies for DC arc hazard computations have been published [8], [9]. In this paper, some of the most relevant methods are reviewed and of most significance, these methods are compared to test data from novel DC arc tests conducted at Kinectrics High Current Laboratory (e.g. the tests for Bruce Power and Coast Mountain Bus Company). In particular the transit industry should find this information relevant to conducting due diligence arc hazard studies on rail and transit systems involving DC power at 6V and below. In a transit industry survey conducted for Kinectrics Inc., it was apparent that presently, transit regulators and standard developers such as the Federal Railway Administration (FRA), Federal Transit Administration (FTA) and the American Public Transit Association (APTA) have no inspection, compliance or standard programs that deal specifically with arc hazard assessment. For guidance on arc hazard assessment, corporations in each State generally default to Federal or State OSHA safety regulations (which applies NFPA 7E as the standard for compliance). Ultimately, it is clear that transit employers are obligated to ensure that workers who may be exposed to electric arcs must be clothed to prevent enhanced injury. Rulings have been awarded against transit companies as illustrated in reference [4], which describes one of the highest awards made to an ex-railroad worker. Survey results indicated that many rail companies in North America are aware of the need
2 for arc flash safety programs; nevertheless, only a few have taken the initiative to put these in place and these are generally at the early stages of program development. One of the difficulties faced by these organizations is how to compute arc hazards related to DC electric systems. Electric Arcs An electric arc is the passage of current through ionized air. The axial temperature of an arc column can reach 15, to 25, C. In addition to the radiated thermal energy, tremendous amounts of noise (15 db) and pressure (2 lb/ft 2 ) can also be released from electric arcs. Accidental arcs can be caused by foreign object bridging of phases, dielectric breakdown and mechanical failure. The severity of incident energy levels (which will be the focus of this paper) released from electric arcs is dependent on the following parameters: System voltage Available fault current Fault duration Arc length or gap distance Working distance Electrode materials Enclosure around arc AC or DC Number of phases involved Arc motion Figure 1 to Figure 4 show sample waveforms of AC and DC arcs. The waveforms were obtained from controlled laboratory experiments at Kinectrics Figure 1. AC Arc Current Waveform Figure 2. AC Arc Voltage Waveform Figure 3. DC Arc Current Waveform Figure 4. DC Arc Voltage Waveform As seen from the figures, there exist considerable differences between the AC and DC arcs. Below are some of the major differences: AC arcs encounter zero-crossing, but DC arcs do not. Therefore, under the assumption that all other parameters remain
3 constant, DC arcs generate more energy than AC arcs because DC arcs will not have ignition and re-ignition. The diameter of DC arc s plasma column remain constant, AC arcs plasma column expands and contracts. DC arcs are more difficult to extinguish. DC arcs decay characteristics are dependent on the source (ie battery systems have a finite capacity to sustain the arc). DC ARC TESTI G AT KI ECTRICS Kinectrics Inc. has conducted the pioneering DC arc hazard tests and modeling at their unique High Current Laboratory. Kinectrics has recently completed DC arc flash test for both Bruce Power (power generation company in Ontario, Canada) and Coast Mountain Bus Company (public transit company in Vancouver, Canada). Figure 5 shows a sample open-air arc flash test conducted at Kinectrics High Current Laboratory. Fault duration:.1 to 2 seconds Working distance: 6, 12, 22 and 34 Arcing environment: Open air and enclosed Electrode configurations: Vertical, horizontal and series With the results obtained from the various tests, Kinectrics has examined the relationship between incident energy and working distances from DC arcs, estimated arcing fault current from bolted fault current, and derived equations to predict the amount of incident energy released from DC arcs. Kinectrics has also compared the measured incident energy and ArcPro TM predictions. The following subsections show the sample test results and some of the DC arc hazard developments achieved by Kinectrics. 13 V and 26 V DC Test Results Figure 6 shows the measured heat flux from DC arcs of various lengths and at various available arcing currents for tests using a 26 V DC source. Controlled DC arcs were generated between 2 vertical electrodes. At 26 VDC, 1 and 2 inch arc could easily be sustained at higher arcing faults. The probability of sustaining arcs is highly dependent on the electrode configuration, the source voltage and on the current. Figure 5. Sample Arc Flash Test For the DC testing, a special low-impedance transformer was used to obtain the desired voltage and current range. The output of the transformer was connected to one or two high-power three-phase rectifiers to produce a DC power source. The current magnitude was controlled by adding resistance or inductance in the circuit on the output of the rectifier. Precise control of arc times was controlled by a test sequencer and a synchronous make-switch and circuit breaker. DC arc flash testing at Kinectrics has covered the following range of variables: System voltage: 125 V, 25 V and 6V DC Bolted fault current: 1 ka to 25 ka Arc gap distance:.2 to 6 Figure 6. 26V DC Heat 12 with 1 and 2 Arc Gap Extrapolating the heat flux data measured for 26V arcs, graphs of incident energy at 12 inches as a function of time were produced for different fault currents levels. The threshold of the hazard/risk categories set by NFPA 7E were also plotted on these graphs for 26V DC arcs. Figure 7 shows incident energy as a function of time for 26 V DC arcs with 2 gaps. Such curves can serve as a guide for the incident energy from DC arcs for a range of possible fault conditions.
4 measured values were averages. Also, the computed values are intended to be more conservative and more representative of the maximum hazards. 6 V DC Test Results Figure 7. FPA 7E Categories 12 Working Distance; 2 Arc Gap Distance; 26 V DC DC vs. AC Incident Energy Comparisons can be made between the results from the AC and DC tests with respect to the incident energy vs. fault current with a fixed arc gap. Comparisons were made using data from tests with 1 and 2 gaps and heat flux measured at 24 away from the arc. Similar fault currents were used for both AC and DC arcs. The curves in Figure 8 illustrate the results of the measurements at 26 V DC compared to AC with 1 and 2 arc gap distances. Note that DC arc energy is consistently higher than AC arc energy for the same current (DC vs. AC rms). The average value per unit difference in the range from 2, A to 1, A was estimated to be approximately V DC arc flash tests were performed in both open-air (electrodes pointing towards one another) and enclosed (electrodes pointing downwards and electrodes pointing outwards). It was observed that with arcs in a box, the two electrode configurations make very little differences with respect to the amount of incident energy captured by the calorimeter. Regardless of which direction the electrodes point, once the arc is generated, radiated incident energy will be deflected off the sidewalls of the box and captured by the calorimeter at the front opening. This also explains that radiated incident energy from an enclosed environment is always higher than that from an open environment if all other parameters remain unchanged. The objective of the test was to derive equations to calculate arcing fault current at 6 V DC and ultimately, to predict the amount of incident energy released from DC arcs at a specified working distance away from the potential arc. The empirically derived equations are as follows: = ( 1) =( ) (.4793 ln( )+1.27).1 6 where: is the arcing fault current in ka is the bolted fault current in ka G is the arc gap distance in inches t is the fault duration in seconds D is the working distance in inches The equations were derived under the following laboratory testing conditions: Figure 8. AC vs. DC Heat Flux Comparison at 24 Working Distance Figure 8 includes the ArcPro TM computation results along with the measured data. It shows that DC average currents produce higher incident energies than numerically equivalent AC rms currents. ArcPro TM computations are generally higher than the AC measured values, mostly due to the fact that the 6 V DC Bolted fault current of 2 ka to 25 ka Arc gap distance of up to 6 (depending on the configuration of the electrodes and the available fault current, arcs may not be sustainable at an arc gap distance of 6 )
5 As with all curve fit approximations, the above equations should be considered valid within the range of parameters in the data used to derive the equations. Figure 9 shows the relationship between bolted fault currents and arcing fault currents with arc gap distances of 1, 3 and 6. As obvious from the curves, there is an inverse correlation between the arcing fault currents and the arc gap distances. Arcing Fault Current (ka) Bolted Fault Current vs. Arcing Fault Current at 6 V DC 1" Arc Gap 3" Arc Gap 6" Arc Gap Bolted Fault Current (ka) Figure 9. Arcing Fault Current vs. Bolted Fault Current under Various Arc Gap distances at 6 V DC It can be noted from Figure 9 that at 2 ka or below, the arcing fault current is approximately equal to the bolted fault current. For the specific lab setup and tests conducted, the arcing fault currents always remain between 64% and 97% of the bolted fault currents. To identify how incident energy from DC arcs varies with working distances, fault durations were normalized as seen in Figure 1 below. As a result, incident energy can be plotted as heat flux. For instance, if the working distance is doubled, the incident energy would decrease by a factor of four. This relationship is true only under the circumstances that the energy readings captured by the calorimeters are 1% radiated thermal energy released by the arc, e.g. This is likely true for the more distant measurements but calorimeters as close as 6 are likely to be influenced by contact with hot arc plasma. In testing this generally leads to a wide range of incident energy values for calorimeters that are very close to the arc. The following figure shows similar information as Figure 7, it displays the resulting incident energy with the arcing fault currents and durations. The curves can be extrapolated to predict incident energy levels of longer duration. The incident energies were measured at 12 away from the arc with an 1 arc gap. Incident Energy (cal/cm2) Incident Energy at 12" vs. Arc Duration for 1" Gap Arcing Current at 6 VDC 2 ka 8.6 ka 13.4 ka Cat Cat 1 Cat 2 Cat Arc Duration (s) Figure 11. Arcing Fault Current and Duration vs. Incident Energy Heat Flux (cal/cm2/s) DC Heat Flux Comparison for 1" Arc for Various Distance.1 second arc.5 second arc Distance from Arc (inches) Figure 1. Heat Flux vs. Working Distances As expected, heat flux or incident energy varies inversely with the square of the working distances. COMPARISO OF DC ARC MODELS At the time of writing, there is no standardized and verified model to determine incident energy released from DC arcs. Another DC arc flash hazard equation is proposed in a paper by Doan [8]. This set of equations, as shown below, is applicable for DC systems rated up to 1 V. where: =.5 is the system voltage in volts is the system resistance, in ohms is the arcing time in seconds
6 R is the working distance from the arc, in centimeters is the estimated DC arc flash incident energy at the maximum power point, in cal/cm 2 For exposures where the arc is in a box or enclosure, the proposal suggests using a 3-times multiplying factor for the resulting incident energy value. Based on laboratory test results, this calculation is shown to be conservative and estimates higher than measured incident energy levels. A comparison of Doan s equation 1, ArcPro TM with a modification factor derived from the DC arc flash tests at 12 V and 26 V DC, and the test results at 6 V DC is shown in the following figure. Heat Flux (cal/cm2/s) Heat Flux at 12 inches vs. Arcing Fault Current 6 VDC 1" Arc Gap 6" Arc Gap Doan Arcpro 1" Arcpro 6" Arcing Fault Current (ka) Figure 12. Comparison of Existing DC Arc Flash Evaluation Methods As seen from Figure 12, under the specific scenario, ArcPro TM with factor matches well with the results from the 6 V DC test. It is also important to note that Doan s equation is designed for worst case energy and produced the same results independent of the value of the arc gap. RECOMME DATIO S An interim approach for performing arc flash evaluation at DC equipment could include: 1. ArcPro TM with factors has been verified for the following conditions: 13 V DC to 26 V DC 1 It is assumed that I bf = 2 I arc, where I arc is measured from the laboratory experiment at Kinectrics Bolted fault current of 2 ka to 25 ka Arc gap distance of up to.5 for 13 V DC systems and up to 2 for 26 V DC systems 2. The set of 6 V DC equations Kinectrics derived should be used under the following conditions: 6 V DC Bolted fault current of 2 ka to 25 ka Arc gap distance of up to 6 (depending on the configuration of the electrodes and the available fault current, arcs may not be sustainable at an arc gap distance of 6 ) 3. In situations where the case being assessed does not fall in 1. or 2. the maximum arc energy equation proposed by Doan could be used as a conservative approach. Further testing and studies are required in order to derive more practical models and formulae. CO CLUSIO S Arc hazard analysis is a safety assessment, dedicated to protecting workers who might be exposed to radiated thermal energy from electric arcs. In this paper, the focus is on incident energy released from DC arcs, which should be of particular interest to the transit industry. OSHA states clearly that it is the employers responsibilities to ensure that the employees are adequately protected with PPE. Based on the research and testing conducted at Kinectrics, the following can be concluded: 1. At present, there is no standardized and verified model to determine incident energy released from DC arcs. 2. An initial set of DC arc measurements from Kinectrics laboratories can be used as a verification tool for proposed DC arc hazard analysis tools. 3. The DC arc flash formulas proposed by Doan is conservative compared to measurements. Use of Arcpo TM and the 6 V DC arc hazard equation developed by Kinectrics, is suitable within the range of parameters for which these models have been verified.
7 4. There is a need for additional development of DC arc models. Extrapolation may produce misleading results. 5. It is critical to understand the applications and limitations of the existing models and equations. 6. The transit industry with DC systems for 3 rd rail and cantenary applications should find the test results and preliminary computation methods mentioned in this paper useful for initial DC arc hazard assessments. ACK OWLEDGEME TS [6] Doughty, R., Neal, T. and Floyd, L.. Predicting Incident Energy to Better Manage the Electric Arc Hazard on 6 V Power distribution Systems, United States. [7] ArcPro TM Software, Kinectrics Inc.. [8] Doan, D.. Arc Flash Calculations for Exposures to DC Systems, Delaware, United States. [9] Ammerman, R. et al.. DC Arc Models and Incident Energy Calculations, Colorado, United States. The authors would like to thank the following individuals and corporate for their contributions on this paper: Carl Keyes, Associate, Kinectrics Inc. Claude Maurice, High Current Laboratory Manager, Kinectrics Inc. Coast Mountain Bus Company Bruce Power Inc. REFERE CES [1] IEEE Standards Association: Industry Backs IEEE/ FPA Arc Flash Testing Program with Initial Donations of $1.25 Million. Retrieved May 8, 28, from Institute of Electrical and Electronics Engineers website: l [2] Neitzel, D. (26). The Hazards of Electricity Do You Know What They Are?, Texas, United States. [3] Harrell, J.. "Pieper Electric to challenge OSHA citations". Daily Reporter (Milwaukee). FindArticles.com. March 25, /ai_n / [4] Stannard, E.. "Injured Ex-Metro-North Worker Awarded $1.1M". New Haven Register. April 13, aa3ctrailaward4131.txt?viewmode=fullstory [5] Lee, R. (1982). The Other Electrical Hazard: Electric Arc Blast Burns, United States.
{40C54206-A3BA D8-8D8CF }
Informative Annex D Incident Energy and Arc Flash Boundary Calculation Methods This informative annex is not a part of the requirements of this NFPA document but is included for informational purposes
More informationElectrical Arc Hazards
Arc Flash Analysis 1996-2009 ETAP Workshop Operation Notes Technology, 1996-2009 Inc. Operation Workshop Technology, Notes: Arc Inc. Flash Analysis Slide 1 Electrical Arc Hazards Electrical Arcs can occur
More informationFirst Draft Language
110.16 First Draft Language (B) Service Equipment. In addition to the requirements in (A), service equipment shall contain the following information: (1) Nominal system voltage (2) Arc flash boundary (3)
More informationArc Flash Mitigation An Overview. Gus Nasrallah, P.E. Electroswitch May 30, 2013
Arc Flash Mitigation An Overview Gus Nasrallah, P.E. Electroswitch May 30, 2013 Agenda Origin of Modern Arc Flash studies Why Now more than before NFPA 70E Standards Protection Zone IEEE 1584 2002 IEEE
More informationDC ARC FLASH. THE IMPLICATIONS OF NFPA 70E 2012 ON BATTERY MAINTENANCE
DC ARC FLASH. THE IMPLICATIONS OF NFPA 70E 2012 ON BATTERY MAINTENANCE William Cantor, P.E. TPI Exton, PA 19341 Phil Zakielarz TPI Exton, PA 19341 Mario Spina Verizon Wireless Uniontown, OH 44685 Abstract
More informationArc Flash Analysis and Documentation SOP
Arc Flash Analysis and Documentation SOP I. Purpose.... 2 II. Roles & Responsibilities.... 2 A. Facilities Maintenance (FM).... 2 B. Zone Supervisors/ Shop Foremen... 2 C. PMCS & CPC... 2 III. Procedures...
More informationArc Flash Calculation Methods
Arc Flash Calculation Methods Course No: E04-033 Credit: 4 PDH Velimir Lackovic, Char. Eng. Continuing Education and Development, Inc. 9 Greyridge Farm Court Stony Point, NY 10980 P: (877) 322-5800 F:
More informationArc Flash Hazard Standards:
Arc Flash Hazard Standards: The Burning Question Presented by Sesha Prasad Specialist Power System Engineer Welcon Technologies At IDC Electrical Arc Flash Forum Melbourne April 14th & 15th 2010. Session
More informationTHREE PHASE PAD MOUNTED DISTRIBUTION TRANSFORMER ARC FLASH TESTING JUNE 23, 2009 FERRAZ SHAWMUT HIGH POWER LABORATORY NEWBURYPORT, MA
THREE PHASE PAD MOUNTED DISTRIBUTION TRANSFORMER ARC FLASH TESTING JUNE 23, 2009 FERRAZ SHAWMUT HIGH POWER LABORATORY NEWBURYPORT, MA Witnessed by: Jim Phillips, PE, Consultant Craig DeRouen, ERMCO Director
More informationNSA, Double layered system: Two Layers of Style IC UQ60 (XCYE) 9.0 oz/yd² 305 g/m² Woven, 88% Cotton 12% Nylon, Navy, January, 2011
Hugh Hoagland Consulting, Inc. Electric Arc Exposure Tests For NSA Fabric System Outer Layer 9.0 oz/yd² 305 g/m² Woven, 88% Cotton 12% Nylon Style IC UQ60 (XCYE) Inner Layer 9.0 oz/yd² 305 g/m² Woven,
More informationPaul Dobrowsky Innovative Technology Services
Significant Changes to NFPA 70E -2009 Edition Paul Dobrowsky Innovative Technology Services 2008 IEEE PCIC 1 Repeat Presentation This has been previously presented 2008 IEEE Electrical Safety Workshop
More informationElectrical Measurement Safety. Sponsored By:
Electrical Measurement Safety Sponsored By: About the Viewer Panel Slides: Go to the Links tab at the top and click on the link to download the PDF of the slides If you re watching the archive version,
More informationARC FLASH PPE GUIDELINES FOR INDUSTRIAL POWER SYSTEMS
The Electrical Power Engineers Qual-Tech Engineers, Inc. 201 Johnson Road Building #1 Suite 203 Houston, PA 15342-1300 Phone 724-873-9275 Fax 724-873-8910 www.qualtecheng.com ARC FLASH PPE GUIDELINES FOR
More information2015 NFPA 70E. SESHA 2015 ARIZONA MINI CONFERENCE December 10, 2015 Intel Corporation
2015 NFPA 70E SESHA 2015 ARIZONA MINI CONFERENCE December 10, 2015 Intel Corporation Introduction Jeffrey A. Pugh, P.E. Pugh Engineering LLC Bachelor of Science Degrees in Electrical Engineering and Computer
More informationNATIONAL ELECTRIC SAFETY CODE 2012 EDITION
NATIONAL ELECTRIC SAFETY CODE (ANSI C2 / NESC) 2012 EDITION Jim Tomaseski IBEW Director of Safety and Health EEI Safety and Health Committee Conference NESC 2012 IMPORTANT DATES SEPTEMBER 1, 2009 - Preprint
More informationSteve Kovach District Sales Engineer
Steve Kovach District Sales Engineer 630-740-7463 Steveekovach@Eaton.com Institute of Electrical and Electronics Engineers American Society of Safety Engineers 1 Electrical Hazards Electrical Hazards Shock
More informationCause, Effect & Mitigation Strategies
WSU HANDS ON RELAY SCHOOL 2019 Arc Flash Fault Cause, Effect & Mitigation Strategies Joe Xavier, Technical Manager West Region Arc Flash Fault - Agenda What is an Arc Flash? Why and when does Arc Flash
More informationCREATING A COMPARATIVE MAP OF RELATIVE POWER FOR DC ARC FLASH METHODOLOGIES. A Thesis. presented to
CREATING A COMPARATIVE MAP OF RELATIVE POWER FOR DC ARC FLASH METHODOLOGIES A Thesis presented to the Faculty of California Polytechnic State University, San Luis Obispo In Partial Fulfillment of the Requirements
More informationA Guide to Establish an Arc Flash Safety Program for Electric Utilities
A Guide to Establish an Arc Flash Safety Program for Electric Utilities by Craig Clarke, P.E. Eaton Corporation 50 Soccer Park Rd. Fenton, MO 63026 (636) 717-3406 CraigClarke@Eaton.com Ilanchezhian Balasubramanian,
More informationARC FLASH & PPE UPDATE. Michael Olivo, P.E. Aaron Ramirez, E.I.T.
ARC FLASH & PPE UPDATE Michael Olivo, P.E. Aaron Ramirez, E.I.T. What is Arc Flash? Arc Flash is the release of heat and light produced when electrical current flows through an air gap between two conductors
More informationREDUCING ARC FLASH HAZARD BY REMOTE SWITCHING
The Electrical Power Engineers Qual-Tech Engineers, Inc. 21 Johnson Road Building #1 Suite 23 Houston, PA 15342-13 Phone 724-873-9275 Fax 724-873-891 www.qualtecheng.com REDUCING ARC FLASH HAZARD BY REMOTE
More informationArc Flash Hazard and Mitigation 2 nd Workshop on Power Converters for Particle Accelerators June 14 16, 2010
Arc Flash Hazard and Mitigation 2 nd Workshop on Power Converters for Particle Accelerators June 14 16, 2010 Paul Bellomo June 14-16, 2010 2nd Workshop on Power Converters for Particle Accelerators - Arc
More informationElectric Arc and associated Hazards in the Rail Transit Industry Are we up to date with current developments?
Electric Arc and associated Hazards in the Rail Transit Industry Are we up to date with current developments? Dev Paul, P.E. AECOM Oakland, CA Abstract: Electrical arcing faults are inherent characteristics
More informationWebinar: An Effective Arc Flash Safety Program
Webinar: An Effective Arc Flash Safety Program Daleep Mohla September 10 th, 2015: 2pm ET Agenda Arc Flash Defined and Quantified NFPA 70E / CSA Z 462 - Recent Updates What is the ANSI Z10 Hierarchy of
More informationArc Flash and NFPA 70E
Arc Flash and NFPA 70E Presented by: J.D. Kyle Safe Work Practices Wearing Proper PPE? OSHA 1910.333 (a) (1) not to work hot or live except : 1. De energizing introduces additional or increased hazards
More informationNFPA-70E. Electrical Safety in the Workplace. Standard for Edition
NFPA-70E Standard for Electrical Safety in the Workplace 2015 Edition NFPA-70E 90.1 Purpose. The purpose of this standard is to provide a practical safe working area for employees relative to the hazards
More informationAPPLYING LOW-VOLTAGE CIRCUIT BREAKERS TO LIMIT ARC FLASH ENERGY
APPLYING LOW-VOLTAGE CIRCUIT BREAKERS TO LIMIT ARC FLASH ENERGY Copyright Material IEEE Paper No. PCIC-2006-2 George Gregory Kevin J. Lippert Fellow Member, IEEE Senior Member, IEEE Schneider Electric
More informationArc Flash Study Principles & Procedures for below 15 kv AC Systems. Xuan Wu, Dennis Hoffman, Ronald Wellman, and Manish Thakur
Arc Flash Study Principles & Procedures for below 15 kv AC Systems Xuan Wu, Dennis Hoffman, Ronald Wellman, and Manish Thakur Agenda Arc Flash Study Purposes Introduction of Arc Flash Arc Flash Risk Locations
More informationOSHA & Arc Flash. Scott Ray Distribution Project Engineer POWER Engineers, Inc.
OSHA & Arc Flash Scott Ray Distribution Project Engineer POWER Engineers, Inc. Outline Arc Flash Overview OSHA Overview Arc Flash Study Next Steps Why This Method? Questions Methodology Steps Analysis
More informationAN EXAMPLE OF A STANDARD ARC FLASH PPE LABELING STRATEGY
The Electrical Power Engineers Qual-Tech Engineers, Inc. 201 Johnson Road Building #1 Suite 203 Houston, PA 15342-1300 Phone 724-873-9275 Fax 724-873-8910 www.qualtecheng.com AN EXAMPLE OF A STANDARD ARC
More informationElectrical Severity Measurement Tool Revision 4
Electrical Severity Measurement Tool Revision 4 November 2017 Electrical Severity Measurement Tool 1.0 Purpose: This tool is intended to measure the severity of exposure to an electrical safety event based
More informationCHANGEABILITY OF ARC FLASH PARAMETERS AND ITS IMPACT ON HAZARD MITIGATION IN LOW VOLTAGE POWER SYSTEMS
CHANGEABILITY OF ARC FLASH PARAMETERS AND ITS IMPACT ON HAZARD MITIGATION IN LOW VOLTAGE POWER SYSTEMS by Abdeslem Kadri Bachelor of Engineering, Boumerdes University INELEC, 1996 A thesis presented to
More informationModelling of Sf6 Circuit Breaker Arc Quenching Phenomena In Pscad
Day 2 - Session IV-A High Voltage 163 Modelling of Sf6 Circuit Breaker Arc Quenching Phenomena In Pscad B. Kondala Rao, Gopal Gajjar ABB Ltd., Maneja, Vadodara, India Introduction Circuit breakers play
More informationADDENDUM NO. 2 PROJECT: COURTLAND PUMP STATION CONTRACT: IFB NO COM.00030
ADDENDUM NO. 2 PROJECT: COURTLAND PUMP STATION CONTRACT: IFB NO. 2018-008-COM.00030 To: Prospective Bidders of Record Date: December 17, 2018 The following changes, additions, revisions, and/or deletions
More informationCopper Core & Coil Transformer
Copper Core & Coil Transformer Transformer Stomach Pain Normal Operation: Transformer internal structures and windings are subjected to mechanical forces due to the magnetic forces. Through fault current
More informationArc Flash Analysis Training
Arc Flash Analysis Training Contact us Today for a FREE quotation to deliver this course at your company?s location. https://www.electricityforum.com/onsite-training-rfq An arc flash analysis study is
More information2018 Consultant s Handbook Division 26 Electrical ARC Flash Hazard Analysis
1 Summary 1.1 Provide a complete Arc Flash Hazard Analysis for the project indicated in the accompanying RFP. The Analysis may be performed: independent of the construction project in concert with the
More informationSECTION SHORT CIRCUIT, COMPONENT PROTECTION, FLASH HAZARD AND SELECTIVE COORDINATION STUDY
SECTION 16075 - SHORT CIRCUIT, COMPONENT PROTECTION, FLASH HAZARD AND SELECTIVE COORDINATION STUDY PART 1 GENERAL 1.1 SUMMARY A. Section Includes: 1. Provide a short-circuit, component protection, flash
More informationElectrical Overcurrent Studies
Electrical Overcurrent Studies 11-01-2011 Deliverables associated with electrical overcurrent studies are as follow : a. Draft Reports i. Construction Related Projects have the following draft reports
More informationSelection of PPE Practical experience of different arc assessment methods and their comparison
Selection of PPE Practical experience of different arc assessment methods and their comparison Dr.-Ing. Thomas Jordan Markus Kauschke Slide 1 ICOLIM 2017 Selection of Arc Flash PPE BSD Electrical Safety
More informationAN EXAMPLE OF A STANDARD ARC FLASH PPE LABELING STRATEGY
The Electrical Power Engineers Qual-Tech Engineers, Inc. 201 Johnson Road Building #1 Suite 203 Houston, PA 15342-1300 Phone 724-873-9275 Fax 724-873-8910 www.qualtecheng.com AN EXAMPLE OF A STANDARD ARC
More informationFt Worth IEEE-PES. Presented by: Doug Harris Specifications Engineer Dallas, TX. Arc-Flash Hazard Mitigation & Selectivity
Ft Worth IEEE-PES Presented by: Doug Harris Specifications Engineer Dallas, TX Arc-Flash Hazard Mitigation & Selectivity Electrical hazards Energized circuit/conductor Today s power system engineer must
More informationA controlled arc-flash, produced in a flashtube. Even though the energy level used is fairly low (85 joules), the low-impedance, low-inductance
An arc flash (also called a flashover), which is distinctly different from the arc blast, is part of an arc fault, a type of electrical explosion or discharge that results from a low-impedance connection
More informationHow OSHA s New Transient Overvoltage Requirements Affect Work Practices. B.A. YEUNG, H. BRANCO Leidos Engineering, LLC USA
21, rue d Artois, F-75008 PARIS CIGRE US National Committee http : //www.cigre.org 2016 Grid of the Future Symposium How OSHA s New Transient Overvoltage Requirements Affect Work Practices B.A. YEUNG,
More informationSpark Gap Surge Protectors For Lv Mains
Spark Gap Surge Protectors For Lv Mains By Phillip Tompson BE(Hons) FIE(Aust) CPEng MIEE Managing Director Introduction In the last year or so spark gap surge protectors have appeared in the Australian
More information3Ø Short-Circuit Calculations
3Ø Short-Circuit Calculations Why Short-Circuit Calculations Several sections of the National Electrical Code relate to proper overcurrent protection. Safe and reliable application of overcurrent protective
More informationSTANDARDIZING ARC FLASH PPE LABELS
The Electrical Power Engineers Qual-Tech Engineers, Inc. 01 Johnson Road Building #1 Suite 03 Houston, PA 1534-1300 Phone 74-873-975 Fax 74-873-8910 www.qualtecheng.com STANDARDIZING ARC FLASH PPE LABELS
More informationENGINEERING COMMITTEE Interface Practices Subcommittee AMERICAN NATIONAL STANDARD ANSI/SCTE
ENGINEERING COMMITTEE Interface Practices Subcommittee AMERICAN NATIONAL STANDARD ANSI/SCTE 108 2006 Test Method for Dielectric Withstand of Coaxial Cable NOTICE The Society of Cable Telecommunications
More informationMethod for Static and Dynamic Resistance Measurements of HV Circuit Breaker
Method for Static and Dynamic Resistance Measurements of HV Circuit Breaker Zoran Stanisic Megger Sweden AB Stockholm, Sweden Zoran.Stanisic@megger.com Abstract S/DRM testing methods usually use long,
More informationKey factors to maintaining arc flash safety
APPLICATI TE Key factors to maintaining arc flash safety Arc flash and blast When an arc fault occurs, the result is a massive electrical explosion. The light and heat emitted by the explosion is known
More informationAC INTERFERENCE OF TRANSMISSION LINES ON RAILWAYS: INFLUENCE OF TRACK-CONNECTED EQUIPMENT I. ABSTRACT
AC INTERFERENCE OF TRANSMISSION LINES ON RAILWAYS: INFLUENCE OF TRACK-CONNECTED EQUIPMENT R. D. Southey, J. Liu, F. P. Dawalibi, Y. Li Safe Engineering Services & technologies ltd. 1544 Viel, Montreal,
More informationDESIGN STANDARD DS 29
Assets Delivery Group Engineering DESIGN STANDARD DS 29 VERSION 1 REVISION 2 MAY 2018 FOREWORD The intent of Design Standards is to specify requirements that assure effective design and delivery of fit
More informationShort Circuit Current Calculations
Introduction Several sections of the National Electrical Code relate to proper overcurrent protection. Safe and reliable application of overcurrent protective devices based on these sections mandate that
More informationAppendix B to Working on Exposed Energized Parts
Working on Exposed Energized Parts. - 1910.269 App B Regulations (Standards - 29 CFR) - Table of Contents Part Number: 1910 Part Title: Occupational Safety and Health Standards Subpart: R Subpart Title:
More informationSECTION OVERCURRENT PROTECTIVE DEVICE COORDINATION STUDY
PART 1 - GENERAL 1.1 DESCRIPTION SECTION 26 05 73 OVERCURRENT PROTECTIVE DEVICE COORDINATION STUDY SPEC WRITER NOTE: Delete between // -- // if not applicable to project. Also, delete any other item or
More informationWestern Electric A V a c u u m T u b e
Western Electric 3 4 6 A V a c u u m T u b e Classification Three eiement coid cathode, gas-fiiied tube For use as a relay or rectifier in special circuits. The elements of the tube consist of a cathode,
More informationTopic 6 Quiz, February 2017 Impedance and Fault Current Calculations For Radial Systems TLC ONLY!!!!! DUE DATE FOR TLC- February 14, 2017
Topic 6 Quiz, February 2017 Impedance and Fault Current Calculations For Radial Systems TLC ONLY!!!!! DUE DATE FOR TLC- February 14, 2017 NAME: LOCATION: 1. The primitive self-inductance per foot of length
More informationDesign Approaches for Hospital Distribution Systems With Considerations for Future Expansion, Operator Safety, and Cost
Design Approaches for Hospital Distribution Systems With Considerations for Future Expansion, Operator Safety, and Cost Adam T. Powell, PE President Emerald Engineering, Inc. Jeffrey L. Small, Sr. Senior
More informationSECTION POWER SYSTEMS STUDIES
PART 1 - GENERAL 1.1 RELATED SECTIONS: Refer to Division 15 for Mechanical requirements. Refer to Division 16 for Electrical requirements. 1.2 OBJECTIVE: A. The short-circuit study is to calculate the
More informationEDS FAULT LEVELS
Document Number: EDS 08-1110 Network(s): Summary: EPN, LPN, SPN ENGINEERING DESIGN STANDARD EDS 08-1110 FAULT LEVELS This standard provides guidance on the calculation, application and availability of
More informationDepartment of Mechanical and Aerospace Engineering. MAE334 - Introduction to Instrumentation and Computers. Final Examination.
Name: Number: Department of Mechanical and Aerospace Engineering MAE334 - Introduction to Instrumentation and Computers Final Examination December 12, 2002 Closed Book and Notes 1. Be sure to fill in your
More informationVACUUM INTERRUPTER APPLICATION NOTES Filename: VIAN X-Rays and Vacuum Interrupters Revision: 0 PAGE 1
Revision: 0 PAGE 1 X-Rays and Vacuum Interrupters INTRODUCTION: Vacuum Interrupters made by Eaton carry a label that warns the user about the possibility of X-radiation. This warning needs some explanation
More informationFUNCTIONS OF CIRCUIT BREAKERS
FUNCTIONS OF CIRCUIT BREAKERS Circuit breakers are designed to carry out the following functions: 1. They must be capable of closing on and carrying full-load currents at rated power factors continuously.
More informationCOMMON SOURCES OF ARC FLASH HAZARD IN INDUSTRIAL POWER SYSTEMS
COMMON SOURCES OF ARC FLASH HAZARD IN INDUSTRIAL POWER SYSTEMS Joost Vrielink Hans Picard Wilbert Witteman Eaton Eaton SABIC-IP Europalaan 202 7559 SC Hengelo Europalaan 202 7559 SC Hengelo Plasticslaan
More informationGenerator Advanced Concepts
Generator Advanced Concepts Common Topics, The Practical Side Machine Output Voltage Equation Pitch Harmonics Circulating Currents when Paralleling Reactances and Time Constants Three Generator Curves
More informationIJSRD - International Journal for Scientific Research & Development Vol. 2, Issue 04, 2014 ISSN (online):
IJSRD - International Journal for Scientific Research & Development Vol. 2, Issue 04, 2014 ISSN (online): 2321-0613 Conditioning Monitoring of Transformer Using Sweep Frequency Response for Winding Deformation
More informationPower Electronics Laboratory-2 Uncontrolled Rectifiers
Roll. No: Checked By: Date: Grade: Power Electronics Laboratory-2 and Uncontrolled Rectifiers Objectives: 1. To analyze the working and performance of a and half wave uncontrolled rectifier. 2. To analyze
More informationTransformer Thermal Impact Assessment White Paper TPL Transmission System Planned Performance for Geomagnetic Disturbance Events
Transformer Thermal Impact Assessment White Paper TPL-007-2 Transmission System Planned Performance for Geomagnetic Disturbance Events Background Proposed TPL 007 2 includes requirements for entities to
More informationECE 2006 University of Minnesota Duluth Lab 11. AC Circuits
1. Objective AC Circuits In this lab, the student will study sinusoidal voltages and currents in order to understand frequency, period, effective value, instantaneous power and average power. Also, the
More informationRF Voltage Breakdown: Case Studies and Prevention
WMB-5 RF Voltage Breakdown: Case Studies and Prevention H. Clark Bell HF Plus h.c.bell@ieee.org References [1] R. Woo, Final Report on RF Voltage Breakdown in Coaxial Transmission Lines, Jet Propulsion
More informationELECTRICAL EQUIPMENT. Inspection. H.H. Sheik Sultan Tower (0) Floor Corniche Street Abu Dhabi U.A.E
ELECTRICAL EQUIPMENT Inspection H.H. Sheik Sultan Tower (0) Floor Corniche Street Abu Dhabi U.A.E www.ictd.ae ictd@ictd.ae Course Introduction: The course begins with the fundamental principles that always
More informationA SEMINAR REPORT PRESENT ON AIR BLAST CIRCUIT BREAKER
A SEMINAR REPORT PRESENT ON AIR BLAST CIRCUIT BREAKER Submitted by :- submitted to:- Tazinder singh E.E. 3 rd year (BBDNIIT) 1 Acknowledgement 2 content Topic Page no. Air blast circuit breaker 04 Principle
More informationUnit 3 Magnetism...21 Introduction The Natural Magnet Magnetic Polarities Magnetic Compass...21
Chapter 1 Electrical Fundamentals Unit 1 Matter...3 Introduction...3 1.1 Matter...3 1.2 Atomic Theory...3 1.3 Law of Electrical Charges...4 1.4 Law of Atomic Charges...4 Negative Atomic Charge...4 Positive
More informationPreface...x Chapter 1 Electrical Fundamentals
Preface...x Chapter 1 Electrical Fundamentals Unit 1 Matter...3 Introduction...3 1.1 Matter...3 1.2 Atomic Theory...3 1.3 Law of Electrical Charges...4 1.4 Law of Atomic Charges...5 Negative Atomic Charge...5
More informationThe Lightning Event. White Paper
The Lightning Event White Paper The Lightning Event Surge Protection Solutions for PTC 1 The Lightning Event There are volumes of information available on what we believe lightning is and how we think
More informationStandards for MV switchgear rated for arc flash protection
Standards for MV switchgear rated for arc flash protection by Bryan Johnson, ABB Switchgear standards historically considered the electrical capability of switchgear with little regard to the effects of
More informationCalculation of Transient Overvoltages by using EMTP software in a 2-Phase 132KV GIS
Calculation of Transient Overvoltages by using EMTP software in a 2-Phase 132KV GIS M. Kondalu, Dr. P.S. Subramanyam Electrical & Electronics Engineering, JNT University. Hyderabad. Joginpally B.R. Engineering
More informationThis section applies to the requirements for the performance of power system studies by both the Design Engineer and the Contractor.
Basis of Design This section applies to the requirements for the performance of power system studies by both the Design Engineer and the Contractor. Background Information A Short Circuit and Coordination
More informationElectrical PIP ELEGL03 Guidelines for Power Systems Analysis
July 2016 Electrical PIP ELEGL03 PURPOSE AND USE OF PROCESS INDUSTRY PRACTICES In an effort to minimize the cost of process industry facilities, this Practice has been prepared from the technical requirements
More informationPRC Generator Relay Loadability. Guidelines and Technical Basis Draft 4: (June 10, 2013) Page 1 of 75
PRC-025-1 Introduction The document, Power Plant and Transmission System Protection Coordination, published by the NERC System Protection and Control Subcommittee (SPCS) provides extensive general discussion
More informationModeling of Lightning Direct Effects Interaction of Continuing Current with Aluminum Skins
Excerpt from the Proceedings of the COMSOL Conference 2010 Boston Modeling of Lightning Direct Effects Interaction of Continuing Current with Aluminum Skins Y. Kostogorova-Beller *,1, R. Collins II 2 1
More informationNew Age Technologies in Construction Safety and Associated Concerns
New Age Technologies in Construction Safety and Associated Concerns Saurav Sinha General Manager BSI Group India Pvt. Ltd. WE SHALL COVER. New age technologies in Construction Safety - Wearable Technology
More informationSECTION LOW VOLTAGE ACTIVE HARMONIC FILTER SYSTEM NEMA 1 ENCLOSED
SECTION 16280 LOW VOLTAGE ACTIVE HARMONIC FILTER SYSTEM NEMA 1 ENCLOSED PART 1 - GENERAL 1.1 SUMMARY This specification defines the requirements for active harmonic filter systems in order to meet IEEE-519-2014
More informationRadio Frequency Emissions Analysis Report Sprint Wireless Water Tank Facility
Radio Frequency Emissions Analysis Report Sprint Wireless Water Tank Facility Site ID: BS3XC490 Site Name: Cedar St. Water Tank Address: 396 Cedar Street, Ashland, MA 0171 Latitude: 4.35300 Longitude:
More informationAMERICAN PUBLIC TRANSIT ASSOCIATION 2003 RAIL TRANSIT CONFERENCE. Cable Rating Considerations for Direct Current Traction Power Systems
AMERICAN PUBLIC TRANSIT ASSOCIATION 2003 RAIL TRANSIT CONFERENCE June 9, 2003 Rating Considerations for R. W. Benjamin Stell. P.E Manager of Power Systems The HNTB Companies 1 Burlington Woods Burlington,
More information5. Black box arc modelling
1 5. Black box arc modelling Circuit-breaker s performance in power system is analysed by representing the circuit-breaker characteristics by a function of electrical parameters such as current/voltage,
More informationExperiment 2: Transients and Oscillations in RLC Circuits
Experiment 2: Transients and Oscillations in RLC Circuits Will Chemelewski Partner: Brian Enders TA: Nielsen See laboratory book #1 pages 5-7, data taken September 1, 2009 September 7, 2009 Abstract Transient
More informationISSN: Page 298
Sizing Current Transformers Rating To Enhance Digital Relay Operations Using Advanced Saturation Voltage Model *J.O. Aibangbee 1 and S.O. Onohaebi 2 *Department of Electrical &Computer Engineering, Bells
More informationWireless System Collocation Presents New Issues For Worker Protection
Wireless System Collocation Presents New Issues For Worker Protection The electricity transmission and distribution community has been unaffected by standards covering radio frequency radiation until now.
More informationPREFACE ********************************************************** IT IS NOT INTENDED THAT THESE STANDARDS BE COPIED AND USED AS A SPECIFICATION!
PREFACE This publication has been prepared as a guide for Architectural and Engineering (A&E) firms in the preparation of documents for the design and construction of new structures and the remodeling
More informationShort-Circuit Apparent Power of System Survey Comments
WG Item 87 Short-Circuit Apparent Power of System Survey Comments Again, the values given in Table 18 are totally unrealistic of system conditions. I do not know any systems for which the short-circuit
More informationPRC Generator Relay Loadability. Guidelines and Technical Basis Draft 5: (August 2, 2013) Page 1 of 76
PRC-025-1 Introduction The document, Power Plant and Transmission System Protection Coordination, published by the NERC System Protection and Control Subcommittee (SPCS) provides extensive general discussion
More informationTest Specification for Type Approval
A2 (1991) (Rev.1 1993) (Rev.2 1997) (Rev. 2.1 July 1999) (Rev.3 May 2001) (Corr.1 July 2003) (Rev.4 May 2004) (Rev.5 Dec 2006) (Rev.6 Oct 2014) Test Specification for Type Approval.1 General This Test
More informationANALYSIS OF FAULTS INTERRUPTED BY GENERATOR
ANALYSIS OF FAULTS INTERRUPTED BY GENERATOR CIRCUIT BREAKER SF 6 ING. VÁCLAV JEŽEK PROF. ING. ZDENĚK VOSTRACKÝ, DRSC., DR.H.C. Abstract: This article describes the analysis of faults interrupted by generator
More informationAMENDMENT NO. 1 SEPTEMBER IS (Part 1) : 2001/IEC (1991) SURGE ARRESTORS
AMENDMENT NO. 1 SEPTEMBER 2011 TO IS 15086 (Part 1) : 2001/IEC 60099-1 (1991) SURGE ARRESTORS PART 1 NON-LINEAR RESISTOR TYPE GAPPED SURGE ARRESTORS FOR a.c. SYSTEMS (The Amendment was originally published
More informationHIGH VOLTAGE AND CURRENT CUT-OFF CAPACITY IN A COMPACT PACKAGE FEATURES
HIGH VOLTAGE AND CURRENT CUT-OFF CAPACITY IN A COMPACT PACKAGE (60A type only) RELAYS A PC board type 80A Connector type 60A Screw terminal type A TM type 300A Connector type RoHS Directive compatibility
More informationDevelopments in Electromagnetic Inspection Methods II
6th International Conference on NDE in Relation to Structural Integrity for Nuclear and Pressurized Components October 2007, Budapest, Hungary For more papers of this publication click: www.ndt.net/search/docs.php3?mainsource=70
More informationFACILITY RATINGS METHOD TABLE OF CONTENTS
FACILITY RATINGS METHOD TABLE OF CONTENTS 1.0 PURPOSE... 2 2.0 SCOPE... 3 3.0 COMPLIANCE... 4 4.0 DEFINITIONS... 5 5.0 RESPONSIBILITIES... 7 6.0 PROCEDURE... 8 6.4 Generating Equipment Ratings... 9 6.5
More informationIB2-1 HIGH AVERAGE POWER TESTS OF A CROSSED-FIELD CLOSING SWITCH>:< Robin J. Harvey and Robert W. Holly
HIGH AVERAGE POWER TESTS OF A CROSSED-FIELD CLOSING SWITCH>:< by Robin J. Harvey and Robert W. Holly Hughes Research Laboratories 3011 Malibu Canyon Road Malibu, California 90265 and John E. Creedon U.S.
More informationtotal j = BA, [1] = j [2] total
Name: S.N.: Experiment 2 INDUCTANCE AND LR CIRCUITS SECTION: PARTNER: DATE: Objectives Estimate the inductance of the solenoid used for this experiment from the formula for a very long, thin, tightly wound
More information