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 0-7381-3624-7 SH95108PDF:ISBN 0-7381-3625-5 SS95
2、108No 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 C57.12.21-1992American National StandardRequirements for Pad-Mounted, Compartmental-Type Self-Cooled,Single-Phase Distribution Tran
3、sformersWith High Voltage Bushings; High-Voltage, 34500 GRYD/19920 Volts and Below; Low-Voltage, 240/120 Volts; 167 kVA and SmallerApproved 5/7/92American National Standards Institute, Inc.Copyright The Institute of Electrical and Electronics Engineers, Inc. Provided by IHS under license with IEEENo
4、t for ResaleNo reproduction or networking permitted without license from IHS-,-,-Copyright The Institute of Electrical and Electronics Engineers, Inc. Provided by IHS under license with IEEENot for ResaleNo reproduction or networking permitted without license from IHS-,-,-Approval of an American Nat
5、ional Standard requires verification by ANSI that the requirements for due process, consensus, and other criteria for approval have been met by the standards developer. Consensus is established when, in the judgment of the ANSI Board of Standards Review, substantial agreement has been reached by dir
6、ectly and materially affected interests. Substantial agreement means much more than a simple majority, but not necessarily unanimity. Consensus requires that all views and objections be considered, and that a concerted effort be made toward their resolution. The use of American National Standards is
7、 completely voluntary; their existence does not in any respect preclude anyone, whether he has approved the standards or not, from manufacturing, marketing, purchasing, or using products, pro cesses, or procedures not conforming to the standards. The American National Standards Institute does not de
8、velop standards and will in no circumstances give an interpretation of any American National Standard. Moreover, no person shall have the right or authority to issue an interpretation of an American National Standard in the name of the American National Standards Institute. Requests for interpretati
9、ons shall be addressed to the secretariat or sponsor whose name appears on the title page of this stand ard. CAUTION NOTICE: This American National Standard may be revised or withdrawn at any time. The procedures of the American National Standards Institute require that action be taken to reaffirm,
10、revise, or withdraw this standard no later than five years from the date of approval. Purchasers of American National Standards may receive current information on all standards by calling or writing the American National Standards Institute. Published by National Electrical Manufacturers Association
11、 130 0 N. 17th Street, Rosslyn, Virginia 22209 Copyright 1996 National Electrical Manufacturers Association All rights reserved. No part of this publication may be reproduced in any form, in an electronic retrieval system or otherwise, without prior written permission of the publisher. Printed in th
12、e United States of AmericaAmerican National Standard Copyright The Institute of Electrical and Electronics Engineers, Inc. Provided by IHS under license with IEEENot for ResaleNo reproduction or networking permitted without license from IHS-,-,-Copyright The Institute of Electrical and Electronics E
13、ngineers, Inc. Provided by IHS under license with IEEENot for ResaleNo reproduction or networking permitted without license from IHS-,-,-i ANSI C57.12.21 - 1992 CONTENTS Page Foreword . iv 1 Scope 1 2 References 1 2.1 General . 1 3 Ratings 2 3.1 Kilovolt - ampere ratings . 2 3.2 Voltage ratings and
14、tap rat ings . 2 4 Basic lightning impulse insulation levels and dielectric test levels 3 5 Tests . 3 5.1 General . 3 5.2 Dielectric tests 3 6 Construction 3 6.1 General . 3 6.2 Bushings and terminals 4 6.3 High - voltage and low - voltage compartments . 4 6.4 Instruction nameplate . 5 6.5 Oil prese
15、rvation 5 6.6 Tanks 5 7 Storage and installation . 6 7.1 Storage . 6 7.2 Installation . 6 8 Other requirements that may be specified for some applications . 6 Copyright The Institute of Electrical and Electronics Engineers, Inc. Provided by IHS under license with IEEENot for ResaleNo reproduction or
16、 networking permitted without license from IHS-,-,-ii ANSI C57.12.21 - 1992 Foreword (This Foreword is not part of Amer ican National Standard C57.12.21 - 1992) The Accredited Standards Committee on Transformers, Regulators, and Reactors, C57, has for a number of years been developing and correlatin
17、g standards on transformers and regulators. The data used in this work have been gathered from many sources, including the standards of the Institute of Electrical and Electronics Engineers and the National Electrical Manufacturers Association, reports of committees of the Edison Electric Institute,
18、 and others. This standard was p repared by the Working Group of the Subcommittee on Distribution Transformers, Overhead and Pad - Mounted, C57.12.2, and is a revision of the 1986 edition. Added to this revision are sections on storage and installation with emphasis being placed on the actual positi
19、on when stored and the consideration of the angle of tilt when installed. At the time of approval, the Working Group members were as follows: Gerald A. Paiva, Chair A. Ghafourian M. Mingoia R. Stahara K. Hanus D. Peters J. Valdes J. Malloy R. Scheu D. Whitley This standard was processed and approved
20、 for submittal to ANSI by Accredited Standards Committee on Transformers, Regulators, and Reactors, C57. Committee approval of the standard does not necessarily imply that all committee members voted for its approval. At the time it approved this standard, the C57 Committee had the following members
21、: Chairman: P. J. Hopkinson, NEMA Delegation Vice Chairman: J. C. Thompson, EL High - Voltage, 34500 GRDY/19920 Volts and Below; Low - Voltage, 240/120 Volts; 167 kVA and Smaller 1 Scope This standard is intended for use as a basis for determining performance, interchangeability, and safety of the e
22、quipment 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 consideration c ertain safety features of single - phase, 60 Hz, mineral - oil - immersed, self - cooled, pad -mounted, c
23、ompartmental - type distribution transformers with high - voltage bushings. These transformers are rated 167 kVA and smaller, with high - voltages of 34500 GRD/19900 volts and below for operation between one phase and grounded neutral, and low - voltage of 240/120 volts. These transformers are gener
24、ally used for step - down purposes from an underground primary cable supply. NOTE Refer to latest federal regulations concern ing polychlorinated biphenyl (PCB) contaminations in transformers. 1.3 This standard covers bushing and terminal arrangements for both radial and loop feed systems. 1.4 This
25、standard does not cover the electrical and mechanical requirements of any accessory devices that may be supplied with the transformer. 2 References 2.1 General All characteristics, definitions, terminology, voltage designations, and tests, except as otherwise specified herein, shall be in accordance
26、 with the following American Natio nal Standards (see 2.2): ANSI C57.12.00 - 1987, American National Standard Requirements for Overhead - Type Distribution Transformers, 500 kVA and Smaller; High - Voltage, 34,500 Volts and Below; Low Voltage, 7970/13800 Y Volts and Below. ANSI C57.12.20 -1988, Amer
27、ican National Standard Requirements for Overhead - Type Distribution Transformers, 500 kVA and Smaller; High - Voltage, 34,500 Volts and Below; Low - Voltage, 7970/13800 Y Volts and Below. ANSI C57.12.28 - 1988, American National Standard for Switchgear and T ransformers Pad - Mounted Equipment Encl
28、osure Integrity . ANSI C57.12.70 - 1978 (Reaff. 1987), American National Standard Terminal Markings and Connections for Distribution and Power Transformers. ANSI C57.12.80 - 1978, American National Standard Terminology for Power and Distribution Transformers. ANSI C57.12.90 - 1987, American National
29、 Standard Test Code for Liquid - Immersed Distribution, Power, and Regulating Transformers and Guide for Short - Circuit Testing of Distribution and Power Transformers. Copyright The Institute of Electrical and Electronics Engineers, Inc. Provided by IHS under license with IEEENot for ResaleNo repro
30、duction or networking permitted without license from IHS-,-,-ANSI C57.12.21 - 1992 2 ANSI/IEEE C5 7.12.91 - 1981, American National Standard Guide for Loading Mineral - Oil - Immersed Overhead and Pad - Mounted Distribution Transformers Rated 500 kVA and Below with 65 C or 55 C Average Winding Rise
31、. 2.2 Revision of American National Standards referred to in this document. When an American National Standard referred to in this document is superseded by a revision approved by the American National Standards Institute, Inc., the latest revision shall apply. 3 Ratings 3.1 Kilovolt - ampere rating
32、s Kilovoltampere r atings shall be continuous and based on not exceeding either a 65 C average winding temperature rise or an 80 C hotspot conductor temperature rise. The temperature rise of the insulating oil shall not exceed 65 C when measured near the top of the tank. These kilovolt - ampere rati
33、ngs are based on the usual temperature and altitude service conditions specified in ANSI/IEEE C57.12.00. The kilovolt - ampere ratings shall be as follows: 25 75 37.5 100 50 167 3.2 Voltage ratings and tap ratings 3.2.1 Voltage r atings shall be in accordance with table 1. 3.2.2 No taps shall be pro
34、vided. Table 1 Transformer high - voltage ratings and insulation levels High - Voltage Rating (Volts) Minimum BIL (kV) 4160 GrdY/2400 60 8320 GrdY/4800 75 12000 GrdY/6930 95 12470 GrdY/7200 95 13200 GrdY/7620 95 13800 GrdY/7970 95 16340 GrdY/9430 95 22860 GrdY/13200 125 23900 GrdY/13800 125 24940 Gr
35、dY/14400 125 34500 GrdY/19920 150 4 Basic lightning impulse insulation levels and dielectric test levels 4.1 Basic lightning impu lse 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 ANSI/IEEE C5
36、7.12.00. Copyright The Institute of Electrical and Electronics Engineers, Inc. Provided by IHS under license with IEEENot for ResaleNo reproduction or networking permitted without license from IHS-,-,-ANSI C57.12.21 - 1992 3 5 Tests 5.1 General Except as specified in 5.2, tests shall be performed as
37、 specified in ANSI/IEEE C57.12.00 and ANSI/IEEE C57.12.90. 5.2 Dielectric tests No applied voltage test is required on the high voltage winding. Induced voltage tests shall be performed by applying between the terminals of one winding a voltage that wil l develop from the high - voltage line termina
38、ls to ground a voltage of 1000 volts plus 3.46 times the rated transformer winding voltage, in no case shall the line to ground voltage developed exceed 40,000 volts for 125 kV BIL and 50,000 volts for 150 kV BIL. For this test the neutral terminal shall be grounded. 6 Construction 6.1 General A pad
39、 - mounted, compartmental - type transformer shall conform to ANSI C57.12.28 and consist of a tank with high voltage and low - voltage cable terminating compartment, as sho wn in figure 1. The compartment shall be separated by a barrier of metal or other rigid material. 6.1.1 The high - voltage and
40、low - voltage compartments shall be located side - by - side on one side of the transformer tank. When viewed from the front, the low - voltage compartment shall be on the right. 6.1.2 Access to the terminal compartments shall be provided by a single door or by individual compartment doors. If indiv
41、idual compartment doors are provided, they shall be so constructed as to provide access to hi gh - voltage compartment only after the door to the low - voltage compartment has been opened. There shall be one or more additional captive fastening devices that must be disengaged before the high - volta
42、ge door can be opened. Where the low - voltage compartment door is of a flat - panel deign, or where only a single door is provided, the door shall have three - point latching with a handle provided for a locking device. If a lift - up hood or single door provides access to both the high - voltage c
43、ompartment and the lo w - voltage compartment, one -point latching with provision for a locking device shall be provided, along with an additional door or lift - out panel that must be removed before access can be gained to the high - voltage compartment. 6.1.3 The bottom edges of the compartments s
44、hall be so constructed as to provide for the use of hold -down devices accessible only from inside the compartments. 6.1.4 The construction of the unit shall be such that it can be lifted, skidded, or slid, or a combination of these, into p lace on the mounting surface without disturbing the high -
45、voltage or low - voltage cables. 6.1.5 The transformer base shall be arranged for rolling in two directions; parallel to and at right angles to one side of the transformer. 6.1.6 The lifting provisions shall be on the tank to provide a distributed balanced lift in a vertical direction for the comple
46、tely assembled transformer and shall be designed to provide a safety factor of 5. The safety factor of 5 is the ratio of the ultimate stress of the materia l used to be working stress. The working stress is the maximum combined stress developed in the lifting provisions by the static load of the com
47、pletely assembled transformer. Copyright The Institute of Electrical and Electronics Engineers, Inc. Provided by IHS under license with IEEENot for ResaleNo reproduction or networking permitted without license from IHS-,-,-ANSI C57.12.21 - 1992 4 6.2 Bushings and terminals 6.2.1 The electrical chara
48、cteristics and clearances of the completely assembled high - voltage bushing and low - voltage terminals shall be as shown in table 2. Table 2 Electrical characteristics and minimum electrical clearances of high - voltage bushings and low - voltage terminals Rating (volts) BIL (kV) 6 0 Hz Dry - One
49、- Minute Withstand (kV) Minimum Clearance Live Parts to Ground* (Inches) 240/120 30 10 1 4160 GrdY/2400 60 21 2 - 1/2 8320 GrdY/4800 75 27 3 - 1/2* 12000 GrdY/6930 to 16340 GrdY/9430 95 35 5* 22860 GrdY/133200 to 24940 grdY/14400 125 42 5 - 3/4* 34500 GrdY/19920 150 70 8* * These dimensions should be increased wherever possible to allow the user ease in making connections. *Where cle
