IEEE Std C57.12.51-2008 IEEE Standard for Ventilated Dry- Type Power Transformers, 501 kVA and Larger, Three-Phase, with High- Voltage 601 V to 34 500 V.pdf

IEEE Std C57.12.51-2008 (Revision of IEEE Std C57.12.51-1981) IEEE Standard for Ventilated Dry- Type Power Transformers, 501 kVA and Larger, Three-Phase, with High- Voltage 601 V to 34 500 V; Low- Voltage 208Y/120 V to 4160 V General Requirements IEEE 3 Park Avenue New York, NY 10016-5997, USA 9 March 2009 IEEE Power Low- Voltage 208Y/120 V to 4160 V General Requirements Sponsor IEEE 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. Introduction This introduction is not part of IEEE Std C57.12.51-2008, IEEE Standard for Ventilated Dry-Type Power Transformers, 501 kVA and Larger, Three-Phase, with High-Voltage 601 V to 34 500 V; Low-Voltage 208Y/120 V to 4160 VGeneral Requirements. This dry-type transformer standard describes ventilated dry-type transformers with self-cooled kilovolt- ampere ratings 501 V to 7500 V and high voltages 601 V to 34 500 V; forced-air-cooled ratings for certain sizes are listed in Clause 9. This standard is the result of an effort encompassing the interests of users, manufactures, and others dedicated to developing voluntary consensus standards primarily for dry-type transformers. Table 2, Table 3, Table 9, Table 11, and Table 12 of this standard have been revised to coordinate with IEEE Std C57.12.01.a Table 4 has been revised to reflect industry practice. The copyright of this standard has been transferred from NEMA to IEEE. This standard is a voluntary consensus standard. Its use is mandatory only when required by a duly constituted legal authority or when specified in a contractual relationship. 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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. A patent holder or patent applicant has filed a statement of assurance that it will grant licenses under these rights without compensation or under reasonable rates, with reasonable terms and conditions that are demonstrably free of any unfair discrimination to applicants desiring to obtain such licenses. Other Essential Patent Claims may exist for which a statement of assurance has not been received. 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 are reasonable or non- discriminatory. Further information may be obtained from the IEEE Standards Association. v Copyright © 2009 IEEE. All rights reserved. Participants At the time this standard was submitted to the IEEE-SA Standards Board for approval, the Ventilated Dry- Type Power Transformers Working Group had the following membership: Paulette Payne Powell, Chair Derek Foster Charles Johnson Richard Marek Sheldon Kennedy The following members of the balloting committee voted on this standard. Balloters may have voted for approval, disapproval, or abstention. William J. Ackerman I. Antweiler Stan Arnot David Barnard Wallace Binder Thomas Bishop Thomas Blair William Bloethe Steven Brockschink Carl Bush Tommy Cooper Jerry Corkran Dieter Dohnal Donald Dunn Gary Engmann Joseph Foldi Paul Forquer Marcel Fortin Jalal Gohari Randall Groves Michael Haas Norman Haggerty Kenneth Hanus Gary Heuston John Houdek James Huddleston Charles Johnson James Jones Sheldon Kennedy J. Koepfinger Jim Kulchisky Saumen Kundu John Lackey Chung-Yiu Lam Stephen Lambert Keith N. Malmedal Richard Marek John W. Matthews Gary Michel Daniel Mulkey Jerry Murphy Michael S. Newman Alvaro Portillo Paulette Payne Powell Iulian Profir Kirk Robbins Michael Roberts Dinesh Pranathy Sankarakurup Bartien Sayogo Hyeong Sim Tarkeshwar Singh James E. Smith Jerry Smith S. Thamilarasan T. Traub John Vergis Kenneth White James Wilson William Wimmer Kipp Yule Matthew Zeedyk Ahmed Zobaa When the IEEE-SA Standards Board approved this standard on 26 September 2008, it had the following membership: Robert M. Grow, Chair Tom A. Prevost, Vice Chair Steve M. Mills, Past Chair Judith Gorman, Secretary Victor Berman Richard DeBlasio Andrew Drozd Mark Epstein Alexander Gelman William R. Goldbach Arnold M. Greenspan Kenneth S. Hanus James Hughes Richard H. Hulett Young Kyun Kim Joseph L. Koepfinger* John Kulick David J. Law Glenn Parsons Ronald C. Petersen Chuck Powers Narayanan Ramachandran Jon Walter Rosdahl Anne-Marie Sahazizian Malcolm V. Thaden Howard L. Wolfman Don Wright *Member Emeritus Also included are the following nonvoting IEEE-SA Standards Board liaisons: Satish K. Aggarwal, NRC Representative Michael Janezic, NIST Representative Lorraine Patsco IEEE Standards Program Manager, Document Development Matthew J. Ceglia IEEE Standards Program Manager, Technical Program Development vi Copyright © 2009 IEEE. All rights reserved. Contents 1. Overview 1 1.1 Scope. 1 1.2 Purpose 1 2. Normative references 2 3. Definitions 2 4. Usual service conditions. 2 5. Ratings and characteristics. 2 5.1 Kilovolt-ampere ratings. 2 5.2 Kilovolt-ampere and voltage ratings 3 5.3 Taps. 3 5.4 Insulation levels. 3 5.5 Angular displacement and terminal markings. 4 5.6 Percent impedance voltage 5 6. Construction. 5 6.1 Insulation system. 5 6.2 Accessory location. 5 6.3 Nameplate 6 6.4 Transformer connections. 6 6.5 Tap changing. 7 6.6 Lifting, jacking, and moving facilities. 7 6.7 Ground pad 8 6.8 Transformer enclosure. 9 7. Routine tests. 10 8. Tolerances 10 9. Other ratings and characteristics. 10 9.1 Forced-air-cooled ratings. 10 9.2 40 °C average ambient temperature conditions. 11 9.3 Other winding temperature rises 11 9.4 Other temperature class insulation systems. 11 9.5 Other high-voltage ratings and connections 12 9.6 YY connected transformers. 13 9.7 Increased neutral insulation. 15 9.8 Other basic lightning impulse insulation levels. 15 vii Copyright © 2009 IEEE. All rights reserved. 10. Other construction 16 10.1 High-voltage connection arrangements. 16 10.2 Low-voltage connection arrangements 16 10.3 Surge arresters. 16 10.4 Unit substation application 17 10.5 Temperature devices 17 10.6 Forced-air cooling 17 10.7 Provision for future forced-air cooling 17 10.8 Space heaters. 18 10.9 Current transformers (or provision for their addition in the future). 18 10.10 Terminal blocks. 18 10.11 Contacts. 18 11. Other tests. 18 Annex A (informative) Bibliography. 19 viii Copyright © 2009 IEEE. All rights reserved. IEEE Standard for Ventilated Dry- Type Power Transformers, 501 kVA and Larger, Three-Phase, with High- Voltage 601 V to 34 500 V; Low- Voltage 208Y/120 V to 4160 V General Requirements IMPORTANT NOTICE: This standard is not intended to ensure safety, security, health, or environmental protection in all circumstances. 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 publications 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. 1.1 1.2 Overview Scope This standard is intended to set forth characteristics relating to performance, limited electrical and mechanical interchangeability, as well as safety of the equipment described, and to assist in the proper selection of such equipment. Specific rating combinations are described in the range from 750/1000 kVA to 7500/10 000 kVA inclusive, with high-voltage 601 V to 34 500 V inclusive and low-voltage 208Y/120 V to 4160 V inclusive. This standard does not apply to other types of transformers such as specialty, ventilated dry-type 500 kVA and smaller, sealed dry-type, pad-mounted dry-type, liquid immersed, instrument, regulating, furnace, mine, and rectifier transformers. Transformers with high voltage 600 V or less are excluded. Purpose This standard describes certain electrical and mechanical characteristics and takes into consideration certain safety features of 60 Hz, two-winding, three-phase, ventilated dry-type transformers with self-cooled ratings 501 kVA and larger, which are generally used for step-down purposes. Forced-air-cooled ratings for certain sizes are listed in Clause 9. 1 Copyright © 2009 IEEE. All rights reserved. IEEE Std C57.12.51-2008 IEEE Standard for Ventilated Dry-Type Power Transformers, 501 kVA and Larger, Three-Phase, with High-Voltage 601 V to 34 500 V; Low-Voltage 208Y/120 V to 4160 VGeneral Requirements 2. 3. 4. 5. 5.1 Normative references The following referenced documents are indispensable for the application of this document (i.e., they must be understood and used, so that each referenced document is cited in text and its relationship to this document is explained). For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments or corrigenda) applies. IEEE Std C57.12.01TM, IEEE Standard General Requirements for Dry-Type Distribution and Power Transformers, Including Those with Solid-Cast and/or Resin Encapsulated Windings.1,2 IEEE Std C57.12.70TM, IEEE Standard Terminal Markings and Connections for Distribution and Power Transformers. IEEE Std C57.13TM, IEEE Standard Requirements for Instrument Transformers. Definitions For the purposes of this standard, the following terms and definitions apply. Transformer terminology as set forth in IEEE Std C57.12.80TM B63 shall apply. The Authoritative Dictionary of IEEE Standards, Seventh Edition B5 should be referenced for other terms not defined. Usual service conditions Service conditions shall be in accordance with those described in IEEE Std C57.12.01TM. Ratings and characteristics Kilovolt-ampere ratings Kilovolt-ampere ratings are continuous and based on not exceeding a 150°C average winding temperature rise, as measured by resistance with a 220 °C temperature class insulation system (220 °C limiting temperature) as defined in IEEE Std C57.12.01. The preferred self-cooled (AN) kilovolt-ampere ratings are 750, 1000, 1500, 2000, 2500, 3750, 5000, and 7500 kVA. 1The IEEE standards or products referred to in this clause are trademarks of the Institute of Electrical and Electronics Engineers, Inc. 2IEEE publications are available from the Institute of Electrical and Electronics Engineers, 445 Hoes Lane, Piscataway, NJ 08854, USA (http:/standards/ieee.org/). 3The numbers in brackets correspond to those of the bibliography in Annex A. 2 Copyright © 2009 IEEE. All rights reserved. IEEE Std C57.12.51-2008 IEEE Standard for Ventilated Dry-Type Power Transformers, 501 kVA and Larger, Three-Phase, with High-Voltage 601 V to 34 500 V; Low-Voltage 208Y/120 V to 4160 VGeneral Requirements 5.2 Table 1 Kilovolt-ampere and voltage ratings The preferred kilovolt-ampere and voltage ratings for three-phase self-cooled (AN) transformers are shown in Table 1. Range of kilovolt-ampere and voltage ratings for three-phase (AN) transformers Kilovolt-ampere ratings (kVA) Rated high voltage (V) Low voltage 208Y/120 Low voltages 480, 480Y/277 Low voltages 2400, 4160grdY/2400, 4160 2400 7501000 7501500 4160 7501000 7501500 4800 7501000 7501500 6900 7501000 7502500 7200 7501000 7502500 12 000 7501000 7502500 7507500 12 470 7501000 7502500 7507500 13 200 7501000 7502500 7507500 13 800 7501000 7502500 7507500 23 000 7501000 10002500 15007500 34 500 7501000 10002500 15007500 NOTE 1All voltages are unless otherwise indicated. NOTE 2Kilovolt-ampere ratings separated by a dash indicate that all the intervening ratings listed in 5.1 are included. 5.3 5.4 Taps Four high-voltage winding rated kilovolt-ampere taps shall be provided as follows: two 2.5% taps above rated voltage, and two 2.5% taps below rated voltage. Insulation levels High-voltage line terminal insulation levels shall be in accordance with IEEE Std C57.12.01; Table 2 and Table 3 summarize the preferred insulation