1、IEEE Std 1234-2007IEEE Guide for Fault-Locating Techniques on Shielded Power Cable SystemsIEEE3 Park Avenue New York, NY 10016-5997, USA16 November 2007IEEE Power Engineering SocietySponsored by theInsulated Conductors Committee1234TMIEEE Std 1234-2007 IEEE Guide for Fault-Locating Techniques on Shi
2、elded Power Cable Systems Sponsor Insulated Conductors Committee of the IEEE Power Engineering Society Approved 17 May 2007 IEEE-SA Standards Board Abstract: Tests and measurements that are performed on shielded power cables to identify the location of a fault are described. Whenever possible, the l
3、imitations of a particular test and measurement to locate a fault are provided and recommendations are made regarding specialized fault-locating techniques. A fault characterization chart is included as an aid to select a fault-locating technique. Keywords: arc reflection, cable fault locating, cabl
4、e testing, grounding, safety, sectionalizing, thumping, time domain reflectometry (TDR) _ The Institute of Electrical and Electronics Engineers, Inc. 3 Park Avenue, New York, NY 10016-5997, USA Copyright 2007 by The Institute of Electrical and Electronics Engineers, Inc. All rights reserved. Publish
5、ed 16 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 educational classroom use can also be obtained through the Copyright Clearance Center. Introduction This in
6、troduction is not part of IEEE Std 1234-2007, IEEE Guide for Fault-Locating Techniques on Shielded Power Cable Systems Many fault-locator personnel are experienced in locating short and open circuits on shielded power cables. Proper locating of high-resistance or intermittent cable faults, which are
7、 the majority of the faults on cables with extruded dielectric insulation, is considered tedious, inconsistent, and time-consuming. Therefore, re-closing, re-fusing, burning, and thumping at unnecessarily high voltage and energy levels, in order to generate an open or short circuit, are frequently u
8、sed without consideration of cable and equipment properties. The danger of activating dormant faults, generating new faults, or damaging utility and customer equipment by improper locating methods is not always recognized. By establishing cable fault-locating guidelines and training programs that in
9、corporate recommended cable fault-locating measurements and techniques, cable owners can realize substantial savings in manpower and cable and equipment replacement, and minimize losses from customer outages. Some information and figures in Clause 4, Clause 5, Clause 6, and Annex B, Annex C, and Ann
10、ex D are copyrighted by Gnerlich, Inc. and used with permission. Notice to users Errata Errata, if any, for this and all other standards 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 periodica
11、lly. Interpretations Current interpretations can be accessed at the following URL: http:/standards.ieee.org/reading/ieee/interp/ index.html. Patents Attention is called to the possibility that implementation of this guide may require use of subject matter covered by patent rights. By publication of
12、this guide, no position is taken with respect to the existence or validity of any patent rights in connection therewith. The IEEE 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
13、 the legal validity or scope of those patents that are brought to its attention. iv Copyright 2007 IEEE. All rights reserved. Participants At the time this guide was submitted to the IEEE-SA Standards Board for approval, the C3TF1 Working Group had the following membership: Hans R. Gnerlich, Chair W
14、olfgang B. Haverkamp, Vice Chair Ted. A. Balaska Earle C. Bascom Vern Buchholz Tom C. Champion Jack E. Cherry Frank DiGuglielmo Bill Larzelere Matthew S. Mashikian James D. Medek Dale T. Metzinger John T. Nierenberg John S. Rector Ewell T. Robeson Lawrence W. Salberg Nagu N. Srinivas Gordon W. Whitt
15、en T. Shayne Wright deceased The following members of the individual balloting committee voted on this guide. Balloters may have voted for approval, disapproval, or abstention. James Fitzgerald Arthur R. Fitzpatrick Marcel Fortin Robert B. Gear Hans R. Gnerlich Richard L. Harp Wolfgang B. Haverkamp
16、Stanley V. Heyer Lauri Hiivala Richard A. Huber Lawrence J. Kelly Albert Kong Carl Landinger Gabor Ludasi Gregory Luri Glenn Luzzi Matthew S. Mashikian Spiro G. Mastoras L. Bruce McClung J. D. Medek John E. Merando Jr Gary L. Michel Daleep C. Mohla Shantanu Nandi James J. Pachot Arthur V. Pack Jr Ne
17、al K. Parker Gary Polhill Dennis C. Pratt Radhakrishna V. Rebbapragada Robert A. Resuali Joseph H. Snow Nagu N. Srinivas Frank Stepniak John Tanaka William A. Thue Stephen E. Turner Gerald L. Vaughn Donald A. Voltz Daniel J. Ward Carl Wentzel William D. Wilkens Joe Zimnoch When the IEEE-SA Standards
18、 Board approved this Standard on 17 May 2007, it had the following membership: Steve M. Mills, Chair Robert M. Grow, Vice Chair Don F. Wright, Past Chair Judith Gorman, Secretary Richard DeBlasio Alexander D. Gelman William R. Goldbach Arnold M. Greenspan Joanna N. Guenin Julian Forster* Kenneth S.
19、Hanus William B. Hopf Richard H. Hulett Hermann Koch Joseph L. Koepfinger* John D. Kulick David J. Law Glenn Parsons Ronald C. Petersen Tom A. Prevost Narayanan Ramachandran Greg Ratta Robby Robson Anne-Marie Sahazizian Virginia C. Sulzberger Malcolm V. Thaden Richard L. Townsend Howard L. Wolfman *
20、Member Emeritus v Copyright 2007 IEEE. All rights reserved. Also included are the following nonvoting IEEE-SA Standards Board liaisons: Satish K. Aggarwal, NRC Representative Alan H. Cookson, NIST Representative Lorraine Patsco IEEE Standards Program Manager, Document Development Matthew J. Ceglia I
21、EEE Standards Program Manager, Technical Program Development vi Copyright 2007 IEEE. All rights reserved. Contents 1. Overview 1 1.1 General 1 1.2 Scope . 1 1.3 Purpose 1 2. Normative references 1 3. Definitions, acronyms, and abbreviations 2 3.1 Definitions . 2 3.2 Acronyms and abbreviations . 3 4.
22、 Safety 4 4.1 Safety practices 4 4.2 Responsibility 4 4.3 Precautions 5 4.4 Grounding 5 5. Cable system fault characteristics. 6 5.1 Radial distribution . 6 5.2 Network distribution 8 5.3 Cable system faults 9 6. Cable system fault locating. 10 6.1 Fault-locating preferences chart. 10 6.2 Sectionali
23、zing 11 6.3 Insulation Resistance . 12 6.4 Time domain reflectometry . 13 6.5 Capacitive discharge (thumping). 14 6.6 Burning (fault conditioning) 14 6.7 Surge arc reflection 15 6.8 Burn arc reflection. 16 6.9 Surge pulse reflection 16 6.10 Decay method 17 6.11 Bridge techniques 17 6.12 Tracing/loca
24、ting/pinpointing . 18 Annex A (informative) Bibliography . 21 Annex B (informative) First response cable system fault location in URD . 22 Annex C (informative) Fault location in network feeders 24 C.1 Fault tracing 24 C.2 TDR Assisted fault location 24 Annex D (informative) Fault location on cable
25、systems with concentric neutral corrosion. 26 Annex E (informative) Recommended minimum of fault-locating tools . 27 vii Copyright 2007 IEEE. All rights reserved. IEEE Guide for Fault-Locating Techniques on Shielded Power Cable Systems 1. 1.11.21.32. Overview General This guide has been developed as
26、 a guide for cable fault-locating techniques on shielded power cable systems. It is intended to emphasize those fault-locating techniques that maintain cable integrity, reduce customer outage time, and consider customer equipment sensitivity and safety. This guide applies to all insulated, shielded
27、power cable systems. Scope The introduction of cables with extruded dielectric insulation and of modern splicing technology has imposed new conditions and restrictions on cable fault locating. The use of excessive high voltages and energies during ac, dc, and surge testing of service-aged power cabl
28、e systems with extruded dielectric insulation may overstress insulation, creating defects that become faults after the cables are returned to service. This guide is intended to be applied to medium-voltage distribution cables. Medium-voltage distribution systems generally operate at system voltages
29、above 1 kV and up to 34.5 kV nominal. The end user of the cable circuit should evaluate the necessity for verifying the integrity of extruded dielectric insulated cables, and, if they are in critical service, proceed to perform the high-voltage/energies testing. If not detected during dielectric tes
30、ts, defects in dielectric materials may result in cable failures during the transient voltage surge episodes while in service. Purpose This guide is intended to provide trouble-shooting and testing personnel with information to quickly identify a faulted cable section and/or locate a cable fault wit
31、h minimum risk of further damaging serviceable cables, terminations, and equipment. Normative references The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the
32、referenced document (including any amendments or corrigenda) applies. 1 Copyright 2007 IEEE. All rights reserved. IEEE Std 1234-2007 IEEE Guide for Fault-Locating Techniques on Shielded Power Cable Systems IEEE Std 510-1983, IEEE Recommended Practices for Safety in High-Voltage and High-Power Testin
33、g (Reaff 1992).1, ,2 33. 3.1Definitions, acronyms, and abbreviations Definitions For the purposes of this guide, the following terms and definitions apply. The Authoritative Dictionary of IEEE Standards, Seventh Edition B94, should be referenced for terms not defined in this clause. 3.1.1 aerial ins
34、tallation type: An assembly of insulated conductors installed on a pole or similar overhead structure; it may be self-supporting or installed on a supporting messenger cable. 3.1.2 bolted fault: A cable fault having a resistance value of less than 5 . 3.1.3 branch circuits: A cable system in which i
35、ndependent cables branch out radially from a common source of supply. (See also: radial feed)3.1.4 breakdown: A disruptive discharge through insulation. 3.1.5 cable tray installation type: A structure of ladders, troughs, channels, solid bottom, and other similar devices through which cables systems
36、 may be routed. 3.1.6 characteristic impedance: The driving impedance of the forward-traveling transverse electro-magnetic wave. In cable fault locating, an incident wave on a cable (time domain reflectometer TDR, thumper, etc.) is reflected back to the source positively, negatively, or not at all b
37、y discontinuities and inhomogenities in the cable where impedance values differ from the characteristic cable impedance, respectively. 3.1.7 concentric neutral shield (metallic shield type): Wires helically applied over the semi-conducting insulation shield to carry charging, fault, and neutral curr
38、ents. 3.1.8 conduit installation type: A structure containing one or more ducts. NOTEConduit may be designated as iron pipe conduit, tile conduit, etc.3.1.9 direct buried installation type: Cable laid in a trench or pre-cast trough and covered with sand, specially prepared backfill material, and/or
39、excavated material; or, cable plowed directly into the earth or installed into the earth with guided boring techniques. 3.1.10 direct distribution: A primary feeder or cable that supplies energy directly to a consumer. 3.1.11 drain wires shield (metallic shield type): Wires helically applied over th
40、e semi-conducting insulation shield to carry charging currents only. 3.1.12 extruded dielectrics: Insulation like polyethylene (PE), crosslinked polyethylene (XLPE), tree retardant crosslinked polyethylene (TR XLPE), ethylene propylene rubber (EPR), etc. 3.1.13 flashover: A disruptive discharge thro
41、ugh air around or over the surface of a solid or liquid insulation, between parts at different potential, produced by the application of voltage wherein the breakdown path becomes sufficiently ionized to maintain an electric arc. 1IEEE publications are available from the Institute of Electrical and
42、Electronics Engineers, 445 Hoes Lane, Piscataway, NJ 08854, USA (http:/standards.ieee.org/). 2The IEEE standards or products referred to in this clause are trademarks of the Institute of Electrical and Electronics Engineers, Inc. 3IEEE Std 510-1983 has been withdrawn; however, copies can be obtained
43、 from Global Engineering, 15 Inverness Way East, Englewood, CO 80112-5704, USA, tel. (303) 792-2181 (http:/ 4The numbers in brackets correspond to those of the bibliography in Annex A. 2 Copyright 2007 IEEE. All rights reserved. IEEE Std 1234-2007 IEEE Guide for Fault-Locating Techniques on Shielded
44、 Power Cable Systems 3.1.14 installation types: See: aerial installation type, cable tray installation type, conduit installation type, direct buried installation type, and submarine installation type. 3.1.15 laminated dielectrics: Insulation like paper used in PILC cable design. 3.1.16 LC (longitud
45、inally corrugated) shield (metallic shield type): A longitudinally-applied, corrugated shield of copper or aluminum. LC shields are typically designed to carry both charging and fault currents, and sometimes neutral currents. 3.1.17 lead sheath shield (metallic shield type): An extruded layer of lea
46、d that serves as a metallic shield and also as a hermetic moisture barrier. 3.1.18 loop feed: A number of tie feeders in series, forming a closed circuit. 3.1.19 metal tape shield (metallic shield type): A tape helically applied over the semi-conducting insulation shield. Tape shields are typically
47、designed to carry charging currents and limited fault currents. 3.1.20 network distribution: See: network feeder. 3.1.21 network feeder: A primary feeder that supplies energy to a secondary network. 3.1.22 pinpoint: To locate exactly the fault site for excavation and repair. 3.1.23 pre-locate: Locat
48、ing the general area of a fault as a distance from cable start, end, splice transformer, change in cable type, etc. Identifying a faulted section of cable between two transformers, junction boxes, manholes, etc. 3.1.24 propagation velocity: The velocity at which an electric signal travels through a
49、cable. Propagation velocity is usually expressed in feet, yards, or meters per microsecond or as a percentage of the speed of light. The value of the propagation velocity depends on the (relative) dielectric constant of the insulation material used, the characteristic of the semicon shields, and the cable construction; it is assumed constant for all practical purposes. 3.1.25 radial feed: A cable system in which independent feeders branch out radially from a common source of supply. 3.1.26 reflection coefficient: A measure
