LEADER 04736oam 2200529I 450 001 9911007294903321 005 20211202025256.0 010 $a1-00-320729-4 010 $a1-5231-4448-3 010 $a1-000-52149-4 010 $a87-7022-620-2 010 $a1-003-20729-4 035 $a(CKB)5600000000025160 035 $a(MiAaPQ)EBC6791487 035 $a(Au-PeEL)EBL6791487 035 $a(OCoLC)1273727887 035 $a(OCoLC-P)1273727887 035 $a(FlBoTFG)9781003207290 035 $a(EXLCZ)995600000000025160 100 $a20211007d2021 uy 0 101 0 $aeng 135 $aurcnu|||unuuu 181 $ctxt$2rdacontent 182 $cc$2rdamedia 183 $acr$2rdacarrier 200 10$aOvercurrent protection $eNEC Article 240 and beyond /$fGregory P. Bierals 205 $aFirst edition. 210 1$a[Place of publication not identified] :$cRiver Publishers,$d2021. 215 $a1 online resource (110 pages) 311 $a87-7022-621-0 327 $aCover -- Half Title -- Title Page -- Copyright Page -- Table of Contents -- Preface -- Chapter 1: Definitions -- Chapter 2: Conductor Insulation Withstand Ratings, Terminal Withstand Ratings, Conductor Fusing Currents, and Overcurrent Protection Over 1000 Volts -- Chapter 3: Motor Circuits -- Adjustable-Speed Drive Systems -- Chapter 4: Selective Coordination -- Circuit Breakers -- Chapter 5: A Comprehensive Analysis of a 3-Phase, 4-Wire Distribution System -- Overcurrent Protection - Questions -- Answer key -- Index -- About the Author. 330 $aAn overcurrent is caused by a short-circuit, ground-fault, or an overload. A short-circuit may be hundreds or even thousands of times above the normal operating current. This type of fault may be an arcing fault between ungrounded conductors or between an ungrounded conductor and a grounded (usually, a neutral) conductor, a line-to-line arcing fault may produce a current of 74% of a 3-phase bolted fault. A line-to-neutral arcing fault will be somewhat less. A line-to-line bolted fault, the equivalent, of the conductors bolted together, may be up to 100% of the available short-circuit current. A line-to-neutral bolted fault may be in excess of 100% of the 3-phase bolted fault at the source, but considerably less downstream. A ground-fault, that is, the equivalent of a connection between an ungrounded conductor and the equipment grounding system, will produce a current that may be 38% or higher of the 3-phase bolted fault current. These types of faults are typically arcing faults which normally are intermittent in nature. That is, they strike and restrike over time and may produce a short-circuit fault due to insulation damage. Once again, a line-to-equipment ground fault near the source may produce a fault current of over 100% of the 3-phase bolted fault, but considerably less downstream. An overload typically ranges from one to six times the normal current, and are normally caused by motor starting currents or transformer magnetizing currents. These conditions are of such short duration that the circuit components are not damaged. This book has a detailed analysis of these types of faults, along with explanations and examples of the various types of overcurrent protective devices to assure proper protection. This volume has extensive information on the application of overcurrent protection for conductors and equipment. The reader will be able to calculate fault currents as well as establishing the short-circuit withstand rating of conductor insulation and to determine the appropriate type of overcurrent devices based on circuit conditions. In addition, determining ground-fault currents for the purpose of selecting the proper size of equipment grounding conductors to establish an effective ground-fault current path is discussed in detail. Readership - Anyone involved with the design of overcurrent protection for electrical distribution systems from the system source to the electrical utilization equipment. The emphasis is placed on the design of the overcurrent protection for specific installations to assure proper protection for the circuit components regardless of the type of fault encountered. 606 $aElectric power distribution 606 $aElectric currents$xGrounding 606 $aElectric wiring$xSafety measures 615 0$aElectric power distribution. 615 0$aElectric currents$xGrounding. 615 0$aElectric wiring$xSafety measures. 676 $a621.319 676 $a621.31921 700 $aBierals$b Gregory P.$f1946-$01823167 801 0$bOCoLC-P 801 1$bOCoLC-P 906 $aBOOK 912 $a9911007294903321 996 $aOvercurrent protection$94389667 997 $aUNINA