1、g3g3g3IEEE Standard for Overhead-Type Distribution Transformers 500 kVA and Smaller: High Voltage, 34 500 V and Below; Low Voltage, 7970/13 800Y V and Below Sponsored by the Transformers Committee g3IEEE 3 Park Avenue New York, NY 10016-5997 USA 20 September 2011 IEEE Power Low Voltage, 7970/13 800Y
2、 V and Below Sponsor Transformers Committee of the IEEE Power +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. iv Copyright 2011 IEEE. All rights reserved. Introduction This introdu
3、ction is not part of IEEE Std C57.12.20-2011, IEEE Standard for Overhead-Type Distribution Transformers 500 kVA and Smaller: High Voltage, 34 500 V and Below; Low Voltage, 7970/13 800 Y V and Below. In 1938 the Edison Electric Institute-National Electrical Manufacturers Association (EEI-NEMA) Joint
4、Committee on Standards for Distribution Transformers was organized to develop standards for the various types of distribution transformers. For 23 years the continuous work of this Joint Committee was evidenced by a series of reports published jointly by the Edison Electric Institute (EEI) and the N
5、ational Electrical Manufacturers Association (NEMA). The last report of overhead-type distribution transformers was the Seventh Report published in April 1961. The Joint Committees last two reports on overhead-type distribution transformers were approved as American National Standards; the Seventh R
6、eport was reissued as ANSI C57.12.20-1962. To avoid further duplication of effort and to simplify future revisions, the EEI-NEMA Joint Committee on Standards for Distribution Transformers was dissolved and replaced by new subcommittees of Accredited Standards Committee on Transformers, Regulators, a
7、nd Reactors, C57. The work on standards for overhead-type distribution transformers was taken over by the Subcommittee on Distribution Transformers, Overhead and Pad-mounted, C57.12.2. This standard was prepared by IEEE Subcommittee C57.12.2 on behalf of C57 and is a revision of IEEE Std C57.12.20-2
8、005, IEEE Standard for Overhead Type Distribution Transformers, 500 kVA and Smaller: High Voltage, 34 500 Volts and Below; Low Voltage 7970/13 800Y Volts and Below. The 1981 edition included detailed requirements on relief of excessive pressure. The 1988 revision recognized the step-down and series-
9、multiple designs in distribution transformers, and omitted the platform-type or station-type transformer. In recognition of the dramatic reduction in catastrophic failures of overhead transformers since the formulation of NEMA Standards Proposal Number TR-P7-1975, the 1988 revision included in Secti
10、on 8, this updated NEMA proposal that was previously designated 2.02 of NEMA Standards Publication for Transformers, Regulators, and Reactors, NEMA TR 1-1980 B4.aThe general industry consensus is that transformers that are built in conformance with this standard and that have adequate overcurrent pr
11、otection, and recognizing the limitations included therein, will provide for enclosures with reasonable withstand capability. The 2011 revision includes significant revisions to Clause 9. This standard was processed and approved for submittal to ANSI by Accredited Standards Committee on Transformers
12、, Regulators, and Reactors, C57. Committee approval of the standard does not necessarily imply that all committee members voted for its approval. Notice to users Laws and regulations Users of these documents should consult all applicable laws and regulations. Compliance with the provisions of this s
13、tandard does not imply compliance to any applicable regulatory requirements. Implementers of the standard are responsible for observing or referring to the applicable regulatory requirements. IEEE does not, by the publication of its standards, intend to urge action that is not in compliance with app
14、licable laws, and these documents may not be construed as doing so. aThe numbers in brackets correspond to those of the bibliography in Annex C. Copyrights This document is copyrighted by the IEEE. It is made available for a wide variety of both public and private uses. These include both use, by re
15、ference, in laws and regulations, and use in private self-regulation, standardization, and the promotion of engineering practices and methods. By making this document available for use and adoption by public authorities and private users, the IEEE does not waive any rights in copyright to this docum
16、ent. Updating of IEEE documents Users of IEEE standards should be aware that these documents may be superseded at any time by the issuance of new editions or may be amended from time to time through the issuance of amendments, corrigenda, or errata. An official IEEE document at any point in time con
17、sists of the current edition of the document together with any amendments, corrigenda, or errata then in effect. In order to determine whether a given document is the current edition and whether it has been amended through the issuance of amendments, corrigenda, or errata, visit the IEEE Standards A
18、ssociation web site at http:/ieeexplore.ieee.org/xpl/standards.jsp, or contact the IEEE at the address listed previously. For more information about the IEEE Standards Association or the IEEE standards development process, visit the IEEE-SA web site at http:/standards.ieee.org. Errata Errata, if any
19、, 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 periodically. Interpretations Current interpretations can be accessed at the following URL: http:/standards.ieee
20、.org/reading/ieee/interp/ index.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 i
21、n connection therewith. The IEEE is not responsible for identifying Essential Patent Claims for which a license may be required, for conducting inquiries into the legal validity or scope of Patents Claims or determining whether any licensing terms or conditions provided in connection with submission
22、 of a Letter of Assurance, if any, or in any licensing agreements are reasonable or non-discriminatory. Users of this standard are expressly advised that determination of the validity of any patent rights, and the risk of infringement of such rights, is entirely their own responsibility. Further inf
23、ormation may be obtained from the IEEE Standards Association. v Copyright 2011 IEEE. All rights reserved. Participants At the time this standard was submitted to the IEEE-SA Standards Board for approval, the Overhead Type Distribution Transformers Working Group had the following membership: Alan Tra
24、ut, Chair Charles Simmons, Vice-chair Jerry Allen Jose Alvarez James Armstrong Bikash Basu Paul Buchanan Tom Callsen Charlie Drexler Don Duckett Michael Faulkenberry Marcel Fortin Carlos Gaytan Jose Gamboa Ali Ghafourian Myron Gruber Said Hachichi Michael Hardin Gael Kennedy Robert Olen Justin Pezzi
25、n Martin Rave Mahesh Sampat Stephen Shull Edward Smith Ronald Stahara Christopher Sullivan Donnie Trivitt Antonio Trujilo Alan Wilks The following members of the balloting committee voted on this standard. Balloters may have voted for approval, disapproval, or abstention. William J. Ackerman Samuel
26、Aguirre Peter Balma Steven Bezner Wallace Binder Thomas Blackburn Harvey Bowles Chris Brooks Carl Bush Thomas Callsen Arvind K Chaudhary Bill Chiu Craig Colopy Jerry Corkran Jean-Bernard Dastous Kevin Delahoussaye Gary Donner Charles Drexler Gary Engmann Michael Faulkenberry Bruce Forsyth Marcel For
27、tin Fredric Friend David Gilmer Edwin Goodwin James Graham Randall Groves Said Hachichi J. Harlow Jeffrey Hartenberger Gary Heuston Philip Hopkinson R. Jackson Gael Kennedy Joseph L. Koepfinger David Krause Jim Kulchisky Chung-Yiu Lam Aleksandr Levin Larry A. Lowdermilk Greg Luri John W Matthews Lee
28、 Matthews Daniel Mulkey K. R. M. Nair Dennis Neitzel Michael S. Newman Charles Ngethe Carl Niemann Joe Nims Robert Olen Lorraine Padden Bansi Patel Alvaro Portillo Lewis Powell Michael Roberts Charles Rogers John Rossetti Thomas Rozek Bartien Sayogo Devki Sharma Stephen Shull Gil Shultz Hyeong Sim C
29、harles Simmons James Smith Jerry Smith Steve Snyder Ronald Stahara David Stankes Gary Stoedter David Tepen Alan Traut Joseph Tumidajski John Vergis Jane Verner Daniel Ward William Wimmer vi Copyright 2011 IEEE. All rights reserved. When the IEEE-SA Standards Board approved this standard on 16 June 2
30、011, it had the following membership: Richard H. Hulett, Chair John Kulick, Vice Chair Robert Grow, Past Chair Judith Gorman, Secretary Masayuki Ariyoshi William Bartley Ted Burse Clint Chaplin Wael Diab Jean-Philippe Faure Alex Gelman Paul Houz Jim Hughes David Law Thomas Lee Hung Ling Oleg Logvino
31、v Ted Olsen Gary Robinson Jon Rosdahl Sam Sciacca Mike Seavey Curtis Siller Phil Winston Howard Wolfman Don Wright*Member Emeritus Also included are the following nonvoting IEEE-SA Standards Board liaisons: Satish Aggarwal, NRC Representative Richard DeBlasio, DOE Representative Michael Janezic, NIS
32、T Representative Catherine Berger IEEE Standards Project Editor Erin Spiewak IEEE Standards Program Manager, Technical Program Development vii Copyright 2011 IEEE. All rights reserved. viii Copyright 2011 IEEE. All rights reserved. Contents 1. Overview .1 1.1 Scope .1 1.2 Purpose 1 2. Normative refe
33、rences.1 3. Definitions.2 4. Ratings .2 4.1 Kilovolt-ampere ratings.2 4.2 Voltage ratings and tap ratings 3 5. Basic lightning impulse insulation levels and dielectric test levels.3 5.1 Basic lightning impulse .3 5.2 Dielectric test.3 6. Tests .3 6.1 General 3 6.2 Dielectric tests .3 7. Construction
34、 3 7.1 Bushings and terminals4 7.2 Accessory equipment.5 7.3 Polarity, terminal markings, and angular displacement.7 7.4 Oil preservation .9 7.5 Tanks .9 8. Storage and installation .10 8.1 Storage.10 8.2 Installation.10 9. Design tests for fault current capability of overhead distribution transform
35、er enclosures 10 9.1 Objective .10 9.2 General requirements.11 9.3 Test duties11 9.4 Test duty 1An arcing fault in an enclosure11 9.5 Test duty 2For enclosures with internal fusible elements12 9.6 Test results.12 Annex A (informative) Auxiliary mounting devices.36 Annex B (informative) Flow chart fo
36、r fault current capability tests42 Annex C (informative) Bibliography.43 List of tables Table 1Kilovolt-ampere ratings .13 Table 2Ratings for single-phase transformers (single ratio).13 Table 3Ratings for single-phase transformers (series-multiple).14 Table 4Ratings for three-phase transformers .15
37、Table 5Recommended taps for single-phase and three-phase transformers .16 Table 6Electrical characteristics of bushings .16 Table 7Number of low-voltage terminals and arrangement for single-phase transformers17 Table 8High-voltage terminal sizes17 Table 9Low-voltage terminal sizes 18 Table 10Minimum
38、 electrical clearances (low-voltage terminals600 V and below) .19 Table 11Angular displacement 20ix Copyright 2011 IEEE. All rights reserved. List of figures Figure 1Kilovolt-ampere ratings Segment designations and interchangeability dimensions for single-phase transformers21 Figure 2Segment designa
39、tions and interchangeability dimensions for three-phase transformers .22 Figure 3 Support Lugs A and B.23 Figure 4Number of terminals, description, and arrangement for three-phase transformers 24 Figure 5aTerminal detailsEyebolt25 Figure 5bTerminal detailsSpade H and Spade J 26 Figure 6Connections a
40、nd polarity27 Figure 7 Single-phase 10 kVA to 50 kVA for pole mounting, two-position, single high-voltage cover bushing 28 Figure 8Single-phase 10 kVA to 500 kVA for pole mounting, single-position, single high-voltage cover bushing 29 Figure 9Single-phase 50 kVA to 500 kVA for pole mounting, single-
41、position, single high-voltage cover bushing, two low-voltage cover bushings .30 Figure 10Single-phase 10 kVA to 500 kVA for pole mounting, single-position, sidewall high-voltage bushings.31 Figure 11 Single-phase 10 kVA to 500kVA for pole mounting, single-position, two high-voltage cover bushings.32
42、 Figure 12Single-phase 50 kVA to 500 kVA for pole mounting, single-position, two high-voltage cover bushings, two low-voltage cover bushings33 Figure 13Three-phase 15 kVA to 300 kVA for pole mounting and 500kVA for platform mounting, sidewall high-voltage bushings .34 Figure 14 Three-phase 15 kVA to
43、 300 kVA for pole mounting and 500kVA for platform mounting, cover high-voltage bushings35 Figure A.1Support Lug C 37 Figure A.2Type-C adapter plates.38 Figure A.3Crossarm hangers and kickers (T1 and K1) .39 Figure A.4Crossarm hangers and kickers (T2 and K2) .40 Figure A.5Crossarm hangers .41 x Copy
44、right 2011 IEEE. All rights reserved. IEEE Standard for Overhead-Type Distribution Transformers 500 kVA and Smaller: High Voltage, 34 500 V and Below; Low Voltage, 7970/13 800Y V and Below IMPORTANT NOTICE: This standard is not intended to ensure safety, security, health, or environmental protection
45、. Implementers of the standard are responsible for determining appropriate safety, security, environmental, and health practices or regulatory requirements. This IEEE document is made available for use subject to important notices and legal disclaimers. These notices and disclaimers appear in all pu
46、blications containing this document and may be found under the heading “Important Notice” or “Important Notices and Disclaimers Concerning IEEE Documents.” They can also be obtained on request from IEEE or viewed at http:/standards.ieee.org/IPR/disclaimers.html. 1. Overview 1.1 Scope This standard c
47、overs certain electrical, dimensional, and mechanical characteristics and safety features of single- and three-phase, 60-Hz, mineral-oil-immersed, self-cooled, overhead-type distribution transformers 500 kVA and smaller, high voltages 34 500 V and below and low voltages 7970/13 800Y V and below. 1.2
48、 Purpose This standard is intended for use as a basis for determining the performance, interchangeability, and safety of overhead-type distribution transformers and to assist in the proper selection of this equipment. 2. Normative references The following referenced documents are indispensable for t
49、he application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments or corrigenda) applies. 1 Copyright 2011 IEEE. All rights reserved. IEEE Std C57.12.20-2011 IEEE Standard for Overhead-Type Distribution Transformers 500 kVA and Smaller: High Voltage, 34 500 V and Below; Low Voltage, 7970/13 800Y V and Below IEEE Std C37.40, IEEE Standard Service Conditions and Definitions for High-Voltage Fuses, Distribution Enclo
