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1、Published by the Institute of Electrical and Electronics Engineers, Inc. 142 IEEE Recommended Practice for Grounding of Industrial and Commercial Power Systems IEEE Std 142-2007 (Revision of IEEE Std 142-1991) IEEEBOOKgreen IEEE Std 142 -2007 (Revision of IEEE Std 142-1991) IEEE Recommended Practice
2、 for Grounding of Industrial and Commercial Power Systems Sponsor Power Systems Engineering Committee of the IEEE Industry Applications Society Approved 7 June 2007 IEEE-SA Standards Board The Institute of Electrical and Electronics Engineers, Inc. 3 Park Avenue, New York, NY 10016-5997, USA Copyrig
3、ht 2007 by the Institute of Electrical and Electronics Engineers, Inc. All rights reserved. Published 30 November 2007. Printed in the United States of America. IEEE is a registered trademark in the U.S. Patent +1 978 750 8400. Permission to photocopy portions of any individual standard for educatio
4、nal classroom use can also be obtained through the Copyright Clearance Center. ivCopyright 2007 IEEE. All rights reserved. Introduction This book is a revision of IEEE Std 142-1991, the IEEE Green Book . This recommended practice has served electrical engineers seeking electrical system grounding in
5、formation since the first edition in 1956. It reflects the experience and sound judgment of a working group made up of engineers active in the design and operation of electrical systems for industrial and commercial power systems. Notice to users Errata Errata, if any, for this and all other standar
6、ds can be accessed at the following URL: http:/standards.ieee.org/reading/ieee/updates/errata/index.html. Users are encouraged to check this URL for errata periodically. Interpretations Current interpretations can be accessed at the following URL: http:/standards.ieee.org/ reading/ieee/interp/index.
7、html. Patents Attention is called to the possibility that implementation of this standard may require use of subject matter covered by patent rights. By publication of this standard, no position is taken with respect to the existence or validity of any patent rights in connection therewith. The IEEE
8、 shall not be responsible for identifying patents or patent applications for which a license may be required to implement an IEEE standard or for conducting inquiries into the legal validity or scope of those patents that are brought to its attention. This introduction is not part of IEEE Std 142-20
9、07, IEEE Recommended Practice for Grounding of Industrial and Commercial Power Systems. Copyright 2007 IEEE. All rights reserved.v Participants At the time this standard was submitted to the IEEE-SA Standards Board for approval, the Working Group had the following membership: Elliot Rappaport, Chair
10、 Daleep C. Mohla, Vice Chair Chapter 1: System grounding Donald W. Zipse and Gene Strycula, Co-chairs Chapter 2: Equipment grounding Elliot Rappaport, Chair Chapter 3: Static and lightning protection grounding Donald McCullough II and Donald W. Zipse, Co-chairs Chapter 4: Connection to earth Ken Mic
11、haels, Chair Chapter 5: Electronic equipment grounding Thomas Baldwin, Chair The following members of the individual balloting committee voted on this standard. Balloters may have voted for approval, disapproval, or abstention. Larry Ayer V. Basch Baldwin Bridger William Bush M. Butkiewicz Thomas M.
12、 Gruzs M. Jerath Don O. Koval T. David Mills Neil Nichols Melvin K. Sanders Lynn F. Saunders Srinivasa I. Venugopaian Marcos Andrade Richard Becker W. J. (Bill) Bergman Thomas Blair William Bloethe Stuart Bouchey Baldwin Bridger Frederick Brockhurst Mark Bushnell Keith Chow Donald Colaberardino Step
13、hen P. Conrad Terry Conrad James Daly Stephen Dare Guru Dutt Dhingra Gary Di Troia Gary Donner Randall Dotson Neal Dowling Donald Dunn Randall Groves Thomas M. Gruzs Paul Hamer Robert Hoerauf Darin Hucul Robert Ingham David W. Jackson Joseph Jancauskas Yuri Khersonsky Robert Konnik Don O. Koval Saum
14、en Kundu Stephen R. Lambert Blane Leuschner Jason Lin Michael Lowenstein Richard Loyd Gregory Luri Keith Malmedal William McCoy Donald McCullough II William Moylan Michael Newman Neil Nichols Greg Nolan T. W. Olsen Gregory Olson Lorraine Padden Kostas Pervolarakis Paul Pillitteri Percy Pool Louie Po
15、well Elliot Rappaport Radhakrishna Rebbapragada Michael Roberts Melvin K. Sanders Steven Sano Robert Schuerger Robert Seitz Michael Shirven H. Jin Sim viCopyright 2007 IEEE. All rights reserved. When the IEEE-SA Standards Board approved this standard on 7 June 2007, it had the following membership:
16、Steve M. Mills, Chair Robert M. Gown, Vice Chair Don Wright, Past Chair Judith Gorman, Secretary *Member Emeritus Also included are the following nonvoting IEEE-SA Standards Board liaisons: Satish K. Aggarwal, NRC Representative Alan H. Cookson, NIST Representative Don Messina IEEE Standards Program
17、 Manager, Document Development Patricia A. Gerdon IEEE Standards Program Manager, Technical Program Development Dan Evans Jay Fischer H. Landis Floyd II Marcel Fortin Carl Fredericks Edgar Galyon Travis Griffith Mark McGranaghan John Merando James Michalec Gary Michel T. David Mills James Mitchem Ch
18、arles Morse Abdul Mousa David Smith Robert Smith Devendra Soni Peter Sutherland James Wilson Larry Young Donald W. Zipse Richard DeBlasio Alex Gelman William R. Goldbach Arnold M. Greenspan Joanna N. Guenin Julian Forster* Kenneth S. Hanus William B. Hopf Richard H. Hulett Hermann Koch Joseph L. Koe
19、pfinger* John Kulick David J. Law Glenn Parsons Ronald C. Petersen Tom A. Prevost Narayanan Ramachandran Greg Ratta Robby Robson Anne-Marie Sahazizia Virginia C. Sulzberger Malcolm V. Thaden Richard L. Townsend Howard L. Wolfman Copyright 2007 IEEE. All rights reserved.vii Contents Chapter 1 System
20、grounding. 1 1.1 Introduction1 1.2 Definitions2 1.3 Purposes of system grounding.4 1.4 Methods of system neutral grounding5 1.5 Obtaining the system neutral .22 1.6 Location of system grounding points.28 1.7 Grounding of industrial and commercial generators .38 1.8 Autotransformers.48 1.9 System gro
21、unding for uninterruptible power systems.53 1.10 Portable mining equipment supply systems.57 1.11 Creation of stray currents and potentials .60 1.12 Avoiding common-mode noise62 1.13 Limiting transferred earth potentials63 1.14 “Resonantly” produced voltages64 1.15 Grounding of dc power systems 66 1
22、.16 Normative references.70 1.17 Bibliography 73 Chapter 2 Equipment grounding 75 2.1 Basic objectives .75 2.2 Fundamental concepts77 2.3 Equipment grounding as influenced by type of use.95 2.4 Outdoor open-frame substations95 2.5 Unit substations99 2.6 Installations serving heavy portable electric
23、machinery100 2.7 Interior wiring systems 104 2.8 Interior unit substations and switching centers110 2.9 Utilization equipment.111 2.10 Normative references.114 2.11 Bibliography 116 Chapter 3 Static and lightning protection grounding. 119 3.1 Introduction119 3.2 Static grounding.119 3.3 Lightning pr
24、otection grounding.140 3.4 Normative references.156 3.5 Bibliography 159 viiiCopyright 2007 IEEE. All rights reserved. Chapter 4 Connection to earth. 161 4.1 Resistance to earth.161 4.2 Ground electrodes169 4.3 Methods and techniques of construction174 4.4 Measurement of resistance to earth176 4.5 N
25、ormative references.182 Chapter 5 Electronic equipment grounding. 187 5.1 Introduction187 5.2 Definitions187 5.3 History of computer grounding188 5.4 System or equipment to be grounded.190 5.5 Grounding electronic equipment191 5.6 Effects of internal rectifiers in computers200 5.7 Grounding of shiel
26、ds201 5.8 Interference from radio frequencies.204 5.9 Case histories.205 5.10 Normative references.207 5.11 Bibliography 208 Index . 211 Copyright 2007 IEEE. All rights reserved.1 IEEE Recommended Practice for Grounding of Industrial and Commercial Power Systems Chapter 1 System grounding 1.1 Introd
27、uction 1.1.1 Overview This chapter provides recommended procedures for the system grounding of industrial and commercial power systems, and the proper selection and application of grounding impedances. Special cases of system grounding are also addressed for generators, uninterruptible power supplie
28、s (UPS), portable mining equipment, and multi-voltage systems. 1.1.2 General Grounding of an electrical system is a decision that must be faced sometime by most engineers charged with planning or modifying electrical distribution. Grounding in some form is generally recommended, although there are c
29、ertain exceptions. Several methods and criteria exist for system grounding; each has its own purpose. It is the intention of this chapter to assist the engineer in making decisions on the subject by presenting basic reasons for grounding or not grounding and by reviewing general practices and method
30、s of system grounding. The practices set forth herein are primarily applicable to industrial power systems that distribute and utilize power at medium or low voltage, usually within a smaller geographical area than is covered by a utility. Where distances or power levels may dictate circuitry and eq
31、uipment similar to a utility, consideration of utility practices is warranted. However, restrictions of the National Electrical Code (NEC ), NFPA 70 1 particular needs of service and the experience and training of the workforce should also be considered. 1 Information on references can be found in 1
32、.16. IEEE Std 142-2007CHAPTER 1 2Copyright 2007 IEEE. All rights reserved. Where an industrial power system includes power-generating equipment, the reasons for grounding these components may be the same as those for grounding similar components of public utility systems. The methods of grounding wo
33、uld generally be similar under like conditions of service. However, in the industrial setting, conditions of service may be altered by the following: a)Location within the power system b)Individual generator characteristics c)Manufacturing process requirements All of these may affect grounding decis
34、ions. The NEC, sponsored by the National Fire Protection Association, contains regulations pertaining to system and equipment grounding applicable to industrial, commercial, and special occupancy facilities. These rules are considered minimum requirements for the protection of life and property and
35、should be carefully reviewed during the course of system design. The recommended practices in this document are intended to supplement, and not negate, any of the requirements in the NEC. 1.2 Definitions For the purposes of this document, the following terms and definitions apply. The Authoritative
36、Dictionary of IEEE Standards Terms B8 2 and the NEC should be referenced for terms not defined in this subclause. 1.2.1 effectively grounded: Grounded through a sufficiently low impedance such that for all system conditions the ratio of zero-sequence reactance to positive-sequence reactance ( X 0 /
37、X 1 ) is positive and not greater than 3, and the ratio of zero-sequence resistance to positive-sequence reactance ( R 0 / X 1 ) is positive and not greater than 1. 1.2.2 equipment grounding conductor (EGC): The conductor used to connect the non- current-carrying metal parts of the equipment, racewa
38、ys, and other enclosures to the system grounded conductor, the grounding electrode conductor (GEC), or both, at the service equipment or at the source of a separately derived system. 1.2.3 ground: A conducting connection, whether intentional or accidental, between an electrical circuit or equipment
39、and the earth, or to some other body that serves in place of the earth. 1.2.4 grounded: Connected to earth or to an extended conducting body that serves instead of the earth, whether the connection is intentional or accidental. 1.2.5 grounded system: A system in which at least one conductor or point
40、 (usually the middle wire or neutral point of transformer or generator windings) is intentionally grounded, either solidly or through an impedance. 2 The numbers in brackets correspond to those of the bibliography in 1.17. IEEE SYSTEM GROUNDINGStd 142-2007 Copyright 2007 IEEE. All rights reserved.3
41、1.2.6 grounding system: A system that consists of all interconnected grounding connections in a specific power system and is defined by its isolation from adjacent grounding systems. The isolation is provided by transformer primary and secondary windings that are coupled only by magnetic means. Thus
42、, the system boundary is defined by the lack of a physical connection that is either metallic or through a significantly high impedance. 1.2.7 high-resistance grounded: A resistance-grounded system designed to limit ground- fault current to a value that can be allowed to flow for an extended period
43、of time, while still meeting the criteria of R 0 1 000 000 ohm-cm). 4.2.6 Transferred earth potentials The phenomenon of a difference of potential at one location on the earth with respect to another location is known as transferred earth potential (see Nichols and Shipp). The ground potential rise
44、of a substation may be on the order of some 5000 V, which may be transferred out to a nonfault location by a ground conductor (or metal pipe, rail, etc.) leaving the station. This situation is to be avoided to ensure both personnel and equipment protection at the nonfaulted end. Steps to alleviate t
45、his transferred potential problem include the bonding together of ground mats (that are within a range of approximately 30 m to 90 m (100 ft to 300 ft) apart, and the use of isolation transformers. This problem was recognized by utilities in the application of pilot wire protection where the low-vol
46、tage conductors (pilot wire IEEE Std 142-2007CHAPTER 4 174Copyright 2007 IEEE. All rights reserved. circuit) were interconnecting two remote ground grids. Most of the ameliorating techniques were based on the utilities solution to this basic problem. Rail and pipe isolation joints may be used to lim
47、it the travel of transferred potentials. Additional information on this subject is found in IEEE Std 242 (IEEE Buff Book); IEEE Std 367; IEEE Std 487; Nichols and Shipp; and Rajan and Venugopalan. 4.3 Methods and techniques of construction 4.3.1 Choice of rods Ground rods are manufactured in diamete
48、rs of 9.53, 12.7, 15.88, 19.05, and 25.4 mm (3/8, 1/2, 5/8, 3/4, and 1 in, respectively) and in lengths of 1.5 m to 12.2 m (5 ft to 40 ft). For most applications, the diameters of 2.7, 15.88, and 19.05 mm (1/2, 5/8, and 3/4 in, respectively) are satisfactory. The NEC specified that rods of steel or
49、iron shall be at least 15.88 mm (5/8 in) in diameter and that rods of nonferrous materials shall not be less than 2.7 mm (1/2 in) in diameter. Copper-clad steel, one of the most common types of rods, permits driving to considerable depth without destruction of the rod itself, while the copper coat permits direct copper-to-copper connection between the ground wire and the rod. In addition to the copper-clad steel, galvanized steel rods and stainless steel rods are available. Stainless rods must be reviewed with soil conditions to ensure against the po
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