1、 The Institute of Electrical and Electronics Engineers, Inc.3 Park Avenue, New York, NY 10016-5997, USACopyright 2003 by the Institute of Electrical and Electronics Engineers, Inc.All rights reserved. Printed in the United States of America.Print:ISBN 0-7381-3629-8 SH95111PDF:ISBN 0-7381-3630-1 SS95
2、111No part of this publication may be reproduced in any form, in an electronic retrieval system or otherwise, without the prior written permission of the publisher.ANSI C57.12.25-1990American National Standard for TransformersPad-Mounted, Compartmental-Type, Self-Cooled, Single-Phase Distribution Tr
3、ansformers with Separable Insulated High-Voltage Connectors; High Voltage, 34 500 GrdY/19 920 Volts and Below;Low Voltage, 240/120 Volts; 167 kVA and SmallerRequirementsApproved 05/11/90American National Standards Institute, Inc.iiForeword (This Foreword is not part of American National Standard C57
4、.12.25-1990.)Accredited Standards Committee on Transformers, Regulators, and Reactors, C57, has for many years beendeveloping and correlating standards on transformers and regulators. The data used in this work have been gatheredfrom many sources, including the standards of the Institute of Electric
5、al and Electronics Engineers and the NationalElectrical Manufacturers Association, reports of committees of the Edison Electric Institute, and others.This standard was prepared by the Subcommittee on Distribution Transformers, Overhead and Pad-Mounted,C57.12.2.Suggestions for improvement of this sta
6、ndard will be welcome. They should be sent to the National ElectricalManufacturers Association, 2101 L Street, NW, Washington, DC 20037.This standard was processed and approved for submittal to ANSI by the Accredited Standards Committee onTransformers, Regulators, and Reactors, C57. Committee approv
7、al of this standard does not necessarily imply that allcommittee members voted for its approval. At the time it approved this standard, the C57 Committee had the followingmembers:(Vacant), (Chairman)(Vacant), (Vice-Chairman)C. H. White, (Secretary)Organization RepresentedName of RepresentativeElectr
8、ic Light and Power Group . W. ColeG. GunnelsP. OrehekA. VelazquezD. Soffrin (Alt.)J. Sullivan (Alt.)Institute of Electrical and Electronics Engineers .J. BonnucchiO. ComptonJ. DuttonL. McCormickW. NeiswenderF. Huber, Jr. (Alt.)H. Smith (Alt.)National Electrical Manufacturers Association J. DouglasP.
9、 HopkinsonW. KendallK. LinsleyW. McNuttH. RobinR. SchewR. Uptegraff, Jr.N. Mohesky (Alt.)J. Nay (Alt.)D. Strang (Alt.)Testing Laboratory Group .W. OGradyR. Seelbach (Alt.)Tennessee Valley Authority. L. SmithU.S. Department of Agriculture Rural Electrification Administration J. Arnold, Jr.U.S. Depart
10、ment of Energy. D. TorgensonU.S. Department of the Interior F. Cook, Sr.U.S. Department of the Navy H. StickleyiiiSubcommittee C57.12.2, on Distribution Transformers, Overhead and Pad-Mounted, which developed this standard,had the following members:W. E. Cole, ChairmanC. H. White, Secretary J. C. Ar
11、nold, Jr.A. E. Bolin, Jr.T. P. CopperA. A. GhafourianM. E. GruberK. S. HanusJ. HuntR. D. JordanJ. P. LazarD. S. LyonJ. H. Malloy, Jr.P. A. ManosJ. R. MillerR. P. Miller, SrN. L. MoheskyG. A. PaivaJ. W. SandersR. W. ScheuR. J. StaharaF. StevensR. S. SumrallJ. C. ThompsonA. M. VelazquezA. L. WilksC. W
12、. Williams, Jr.L. E. WilliamsJ. L. Corkran (Alt.)K. D. Edwards (Alt.)T. N. Freeland (Alt.)C. A. Larson (Alt.)D. MacKintosh (Alt.)R. J. Manes (Alt.)M. C. Mingoia (Alt.)D. W. Whitley (Alt.)ivCLAUSE PAGE1. Scope.11.1 11.2 11.3 11.4 12. Normative references 22.1 General. 23. Ratings 23.1 Kilovolt-ampere
13、 ratings . 23.2 Voltage ratings and tap ratings. 24. Basic lightning Impulse insulation levels and dielectric test levels34.1 34.2 35. Tests 35.1 General. 35.2 Dielectric tests 36. Construction 36.1 General. 36.2 Connectors and terminals. 96.3 High-voltage and low-voltage compartment 136.4 Instructi
14、on nameplate. 136.5 Oil preservation 136.6 Tanks 146.7 Components for looped primary cable systems . 147. Storage and Installation.157.1 Storage . 157.2 Installation 158. Other requirements that may be specified for some applications .15Copyright 2003 IEEE All Rights Reserved 1American National Stan
15、dard for Transformers Pad-Mounted, Compartmental-Type, Self-Cooled, Single- Phase Distribution Transformers with Separable Insulated High-Voltage Connectors; High Voltage, 34 500 GrdY/ 19 920 Volts and Below; Low Voltage, 240/120 Volts; 167 kVA and Smaller Requirements1. Scope1.1 This standard is in
16、tended for use as a basis for determining performance, interchangeability, and safety of theequipment covered, and to assist in the proper selection of such equipment.1.2 This standard covers certain electrical, dimensional, and mechanical characteristics, and takes into considerationcertain safety
17、features of single-phase, 60-Hz, mineral-oil-immersed, self-cooled, pad-mounted, compartmental-typedistribution transformers with separable insulated high-voltage connectors. These transformers are rated 167 kVA andsmaller, with high voltages of 34500 GrdY/19 920 volts and below for operation betwee
18、n one phase and groundedneutral, and low voltages of 240/120 volts. These transformers are generally used for step-down purposes from anunderground primary cable supply.NOTE Refer to latest federal regulations concerning PCB contamination in transformers.1.3 This standard covers two connector and te
19、rminal arrangements for loop feed systems. Either Type 1 (see Figure 1) orType 2 (see Figure 2) arrangements shall be specified.1.4 This standard does not cover the electrical and mechanical requirements of any accessory devices that may be suppliedwith the transformer.2 Copyright 2003 IEEE All Righ
20、ts ReservedANSI C57.12.25-1990 2. Normative references2.1 GeneralAll characteristics, definitions, terminology, voltage designation, and tests, except as otherwise specified herein, shallbe in accordance with the following American National Standards. The following standards contain provisions which
21、,through reference in this text, constitute provisions of this American National Standard. At the time of publication, theeditions indicated were valid. All standards are subject to revision, and parties to agreements based on this AmericanNational Standard are encouraged to investigate the possibil
22、ity of applying the most recent editions of the standardsindicated below.ANSI C57.12.20-1988, Transformers - Overhead-Type Distribution Transformers, 500 kVA and Smaller: HighVoltage, 34 500 Volts and Below; Low Voltage, 7970/13 800Y Volts and BelowANSI C57.12.28-1988, Switchgear and Transformers -
23、Pad-Mounted Equipment - Enclosure IntegrityANSI C57.12.70-1978 (R1986), Terminal Markings and Connections for Distribution and Power TransformersANSI/IEEE C57.12.00-1987, General Requirements for Liquid-Immersed Distribution, Power, and RegulatingTransformersANSI/IEEE C57.12.80-1978 (R1986), Termino
24、logy for Power and Distribution TransformersANSI/IEEE C57.12.90-1987, Test Code for Liquid-Immersed Distribution, Power, and Regulating Transformers andGuide for Short-Circuit Testing of Distribution and Power TransformersANSI/IEEE C57.91-1981, Guide for Loading Mineral-Oil-Immersed Overhead and Pad
25、-Mounted DistributionTransformers Rated 500 kVA and Less with 65C or 55C Average Winding RiseANSI/IEEE 386-1985, Separable Insulated Connector Systems for Power Distribution Systems above 600 V3. Ratings3.1 Kilovolt-ampere ratingsKilovolt-ampere ratings are continuous and based on not exceeding eith
26、er a 65C average winding temperature rise oran 80C hot-spot conductor temperature rise. The temperature rise of the insulating oil shall not exceed 65C whenmeasured near the top of the tank. These kilovolt-ampere ratings are based on the usual temperature and altitudeservice conditions specified in
27、ANSI/IEEE C57.12.00-1987. The kilovolt-ampere ratings shall be as follows:3.2 Voltage ratings and tap ratings3.2.1 Voltage ratings shall be in accordance with Table 1 and 6.2.1. For series-multiple transformers, the voltage changeshall be made with a switch handle located in the high-voltage portion
28、 of the terminating compartment. The handleshall be designed to prevent accidental operation by requiring a preliminary step before the voltage setting can bechanged. Actual voltages or position numbers corresponding to the nameplate shall be clearly identifiable near the25 7537.5 10050 167Copyright
29、 2003 IEEE All Rights Reserved 3ANSI C57.12.25-1990handle. There shall be located on or adjacent to the operating mechanism a caution to de-energize the transformerbefore operating.3.2.2 High-voltage windings designed for series-multiple operation shall be connected for the series voltage prior tosh
30、ipment.3.2.3 No taps shall be provided.4. Basic lightning Impulse insulation levels and dielectric test levels4.1 Basic lightning impulse insulation levels (BILs) shall be in accordance with Table 1 and 6.2.1.4.2 Dielectric test levels shall be in accordance with the distribution levels in Table 4 o
31、f ANSI/IEEE C57.12.00-1987. 5. Tests5.1 GeneralExcept as specified in 5.2, tests shall be performed as specified in ANSI/IEEE C57.12.001987 and ANSI/IEEEC57.12.90-1987. 5.2 Dielectric testsNo applied voltage test is required on the highvoltage winding. Induced voltage tests shall be performed by app
32、lyingbetween the terminals of one winding a voltage that will develop from the high-voltage line terminals to ground avoltage of 1000 volts plus 3.46 times the rated transformer winding voltage, but in no case shall the line-to-groundvoltage developed exceed 40 000 volts for 125 kV BIL and 50 000 vo
33、lts for 150 kV BIL. For this test, the neutralterminal shall be grounded.6. Construction6.1 GeneralA pad-mounted compartmental-type transformer shall conform to ANSI C57.12.28-1988 and consist of the tank witha high-voltage and low-voltage cable terminating compartment, as shown in Figures 1 and 2.6
34、.1.1 The high-voltage and low-voltage portions of the compartment shall be located side-by-side on one side of thetransformer tank. When viewed from the front, the low-voltage portion shall be on the right.4 Copyright 2003 IEEE All Rights ReservedANSI C57.12.25-1990 Figure 1 Interchangeability dimen
35、sions - Type-1 arrangementCopyright 2003 IEEE All Rights Reserved 5ANSI C57.12.25-1990Figure 1 Interchangeability dimensions - Type-1 arrangement (continued)6 Copyright 2003 IEEE All Rights ReservedANSI C57.12.25-1990 Figure 2 Interchangeability dimensions - Type-2 arrangementCopyright 2003 IEEE All
36、 Rights Reserved 7ANSI C57.12.25-1990Figure 2 Interchangeability dimensions - Type-2 arrangement (continued)8Copyright2003IEEEAllRightsReservedANSIC57.12.25-1990Table 1 Transformer and connector high-voltage ratings and electrical characteristicsTransformerElectrical characteristics of the completel
37、y assembled high-voltage connectors11For complete connector rating,see ANSl/IEEE 386-1985 .High-Voltage Rating22Transformers are suitable for connectors with phase-to-ground or phase-to-ground/phase-to-phase high-voltage ratings as listed.BIL kV60-Hz dry one minute withstand kVHigh-voltageratings vo
38、ltsMinimumBIL3kV3Arrester coordination may require higher BIL on multiple connection than indicated to achieve a minimum protection level of 20%.Phase-to-ground kVPhase-to-ground/phase-to-phase kVSingle High- Voltage4 160 GrdY/2 400 60 8.3 8.3/14.4 95 348 320 GrdY/4 800 75 8.3 8.3/14.4 95 3412 000 G
39、rdY/6 930 95 8.3 8.3/14.4 95 3412 470 GrdY/7 200 95 8.3 8.3/14.4 95 3413 200 GrdY/7 620 95 8.3 8.3/14.4 95 3413 800 GrdY/7 970 95 8.3 8.3/14.4 95 3416 340 GrdY/9 430 95 (8.3 or 15.2)44The required connector rating is to be specified.(8.3/14.4 or 15.2/26.3)4(95 or 125)4(34 or 40)422 860 GrdY/13 200 1
40、25 15.2 15.2/26.3 125 4023 900 GrdY/13 800 125 15.2 15.2/26.3 125 4024 940 GrdY/14 400 125 15.2 15.2/26.3 125 4034 500 GrdY/19 920 150 21.1 21.1/36.6 150 50Series MultipleHigh-Voltage4 160 GrdY/2 400x 12 470 GrdY/7 20060 x 95 8.3 8.3/14.4 95 344 160 GrdY/2 400x 13 200 GrdY/7 60060 x 95 8.3 8.3/14.4
41、95 348 320 GrdY/4 800x 24 940 GrdY/14 40075 x 125 15.2 15.2/26.3 125 4012 470 GrdY/7 200x 24 940 GrdY/14 40095 x 125 15.2 15.2/26.3 125 4013 200 GrdY/7 620x 24 940 GrdY/14 40095 x 125 15.2 15.2/26.3 125 40Copyright 2003 IEEE All Rights Reserved 9ANSI C57.12.25-19906.1.2 Access to the termination com
42、partment shall be provided by a single door or by individual compartment doors.Ifindividual compartment doors are provided, they shall be so constructed as to provide access to the high-voltageportion of the compartment only after the door to the low-voltage portion of the compartment has been opene
43、d. Thereshall be one or more additional captive fastening devices that must be disengaged before the high-voltage door can beopened. Where the low-voltage compartment door is of a flat panel design, or where only a single door is provided, thedoor shall have three-point latching with a handle provid
44、ed for a locking device. If a lift-up hood or a single doorprovides access to both the high-voltage and low-voltage portions of the compartment, one-point latching withprovision for a locking device shall be provided. (See Figure 3 for typical construction).6.1.3 The bottom edges of the compartment
45、shall be so constructed as to provide for the use of hold-down devices accessibleonly from inside the compartment.6.1.4 The construction of the unit shall be such that it can be lifted, skidded, or slid, or any combination of these, into placeon the mounting surface without disturbing the high-volta
46、ge or low-voltage cables.6.1.5 The transformer shall be arranged for rolling in two directions; parallel to and at right angles to one side of thetransformer.6.1.6 The lifting provisions shall be arranged on the tank to provide a distributed balanced lift in a vertical direction for thecompletely as
47、sembled transformer and shall be designed to provide a safety factor of 5. The safety factor of 5 is theratio of the ultimate stress of the material used to the working stress. The working stress is the maximum combinedstress developed in the lifting provisions by the static load of the completely a
48、ssembled transformer.6.2 Connectors and terminals6.2.1 The electrical characteristics of the completely assembled high-voltage connectors shall be as shown in Table 1. Theelectrical characteristics and clearance of the completely assembled low-voltage terminals shall be as follows:NOTE The minimum c
49、learance of live parts to ground should be increased wherever possible to allow the user easein making connections.Low-voltage rating 240/120 voltsBIL 30 kV60-Hz dry 1-minutewithstand voltage 10 kVMinimum clearance oflive parts to ground 1 inch10 Copyright 2003 IEEE All Rights ReservedANSI C57.12.25-1990 6.2.2 The number, location, and arrangement of the high-voltage connectors and low-voltage terminals shall be as shown inFigures 1 or 2.6.2.3 High-voltage separable insulated connectors shall be provided for connection to the distribution system. T
