1、NEMA Standards PublicationNational Electrical Manufacturers AssociationANSI C12.7-2014Requirements for Watthour Meter SocketsANSI C12.7-2014 Revision of ANSI C12.7-2005 American National Standard for Requirements for Watthour Meter Sockets Secretariat: National Electrical Manufacturers Association A
2、pproved August 14, 2014 American National Standards Institute 2014 National Electrical Manufacturers Association NOTICE AND DISCLAIMER The information in this publication was considered technically sound by the consensus of persons engaged in the development and approval of the document at the time
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17、eaffirm, 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 As
18、sociation 1300 North 17th Street, Suite 900, Rosslyn, Virginia 22209 2014 National Electrical Manufacturers Association. All rights, including translation into other languages, reserved under the Universal Copyright Convention, the Berne Convention for the Protection of Literary and Artistic Works,
19、and the International and Pan American copyright conventions. No 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. Printed in the United States of America ANSI C12.7-2014 ii 2014 National Ele
20、ctrical Manufacturers Association Foreword (This foreword is not part of American National Standard C12.7-2014.) This standard was developed by subcommittee 15 and balloted by the Accredited Standards Committee on Electricity Metering, C12, for full consensus approval as an American National Standar
21、d. This revised version supersedes ANSI C12.7-2005. Certain performance requirements covered by the latest revision of Underwriters Laboratories Standard for Safety on Meter Sockets have been adopted and referred to in this standard. Information on subsequent revisions of these provisions can be obt
22、ained through the Underwriters Laboratories Subscription Revision Service.* This standard covers the dimensions and functions of meter test switches for transformer-rated watthour meters when used in conjunction with instrument transformers. Suggestions for improvements of this standard are welcome.
23、 They should be in the form of a proposed change of text, together with appropriate supporting comments. Comments on standards and requests for interpretations should be addressed to: ANSI Committee C12 Secretary National Electrical Manufacturers Association 1300 North 17th Street, Suite 900 Rosslyn
24、, VA 22209 At the time this standard was completed, the American National Standards Committee C12 had the following membership: Tom Nelson, Chairman Paul Orr, Secretary Organization Represented: Name of Representative: Alabama Power Co. Derl Rhoades Ameren Services James West Baltimore Gas and Elect
25、ric Co. Jim Thurber Center for Neighborhood Technology Lawrence Kotewa Central Hudson Gas & Electric Brett Arteta Consumers Energy David Jirikovic DTE Energy Kostas Tolios Duke Energy Tim Morgan Elster Solutions Scott Weikel EnerNex Corporation Aaron Snyder Florida Power & Light Co . Jim DeMars Futu
26、re DOS R&D Inc. Avygdor Moise *Available from Underwriters Laboratories Inc., 333 Pfingsten Road, Northbrook, IL 60062-2096, USA ANSI C12.7-2014 2014 National Electrical Manufacturers Association iii GE Energy Curt Crittenden Itron, Inc. Brent Cain JECARRCO, LLC Jack, Carr Landis+Gyr John Voisine ME
27、T Laboratories, Inc. Jim Reed Millbank Manufacturing Co. Shawn Glasgow NIST Tom Nelson Oncor Brad Johnson Pacific Gas and Electric Co. D. Young Nguyen Power Measurements William Hardy Public Service Electric & Gas David Ellis Radian Research, Inc. Shannon Edwards SAIC David Scott Schweitzer Engineer
28、ing Labs Travis Mooney Sensus Metering Kenny ODell Silver Spring Networks Kam Oza Technology for Energy Corporation Steve Hudson TESCO Tom Lawton Trilliant Networks Michel Veillette Tucker Engineering Richard Tucker Underwriters Laboratories Scott Hunter Watthour Engineering Lea Wren Xcel Energy Dan
29、 Nordell ANSI C12.7-2014 iv 2014 National Electrical Manufacturers Association At the time this standard was completed, Subcommittee 15 of ANSI Committee C12, which developed and revised this standard, had the following membership: Shawn Glasgow, Chairman Paul Orr, Secretary Organization Represented
30、: Name of Representative: Central Hudson Gas & Electric B. Arteta DTE Energy K. Tolios Duke Energy R. Wesley Elevate Energy L. Kotewa Elster Solutions S. Weikel EnerNex Corporation A. Snyder Florida Power & Light Co. J. DeMars GE Energy C. Crittenden ITI B. Sonnenberg Landis+Gyr J. Voisine Milbank M
31、anufacturing Co. S. Glasgow NIST T. Nelson Oncor B. Johnson Pacific Gas & Electric Co. D. Young Nguyen Power Measurements W. Hardy Public Service Electric & Gas D. Ellis Siemens Industry, Inc. W. Rose Technology for Energy Corporation S. Hudson The Durham Company M. Shoemaker ANSI C12.7-2014 2014 Na
32、tional Electrical Manufacturers Association v TABLE OF CONTENTS Foreword . ii 1 Scope 1 2 References 1 3 Definitions 1 3.1 circuit bypass means (bypass) . 1 3.2 continuous-duty current rating 1 3.3 continuous load . 1 3.4 meter socket (socket): 1 3.5 meter support 1 3.6 ringless-type meter socket 1
33、3.7 ring-type meter socket 1 3.8 socket cover 1 3.9 socket rim . 1 3.10 socket sealing ring 1 4 Electrical Ratings . 2 4.1 Current ratings 2 4.2 Voltage ratings 2 5 Performance Requirements 2 6 Construction Requirements . 2 6.1 Construction and workmanship 2 6.2 Marking . 2 6.3 Enclosures 2 6.3.1 Pr
34、otection 2 6.3.2 Construction 3 6.3.3 Enclosure materials . 3 6.3.4 Mounting bosses . 3 6.3.5 Wiring space 3 6.4 Conduit connections and knockouts . 3 6.5 Limiting dimensions and relative locations of functional parts . 5 6.6 Terminal connectors . 5 6.7 Circuit closing means (bypass) . 6 6.7.1 Horn
35、bypass . 6 6.8 Sealing 6 6.9 Sectional and multiple-opening trough-type sockets 6 6.9.1 Structural types 6 6.9.2 Covers . 6 6.9.3 Meter position spacings . 6 ANSI C12.7-2014 vi 2014 National Electrical Manufacturers Association 6.10 Socket sealing . 6 6.10.1 General 6 6.10.2 Dimensions and tolerance
36、s . 7 6.10.3 Facilities for sealing . 7 6.11 Watthour meter/ringless socket interface . 7 6.12 Metric conversion 7 6.13 Safety alert markings 7 Tables Table 1 300 V Rating 2 Table 2 600 V Rating 2 Table 3 Knockout and Bushing Dimensions . 4 Table 4 Limiting Dimensions and Tolerances . 5 Figures Figu
37、re 1 Limiting Dimensions of Socket Rim 8 Figure 2 Limiting Dimensions and Positions of Socket Jaws 9 Figure 3 Location of Socket Jaws (Front View) 10 Figure 4 Socket-Jaw Position Identification 11 Figure 5 Internal Voltage Connections of 13-, 14-, and 15-Jaw Sockets 12 Figure 6 SocketSealing Ring Di
38、mensions 13 Figure 7 Hole Dimensions to Accommodate Sealing Means 14 Figure 8 Provisions for Interchangeable Gasketless Hubs . 15 Figure 9 Horn Bypass 16 ANSI C12.7-2014 2014 National Electrical Manufacturers Association 1 1 Scope This standard covers the general requirements and pertinent dimension
39、s applicable to watthour meter sockets rated up to and including 600 V and up to and including 320 A continuous duty per socket opening. 2 References This standard shall be used in conjunction with the following standards. When the following standards are superseded by an approved revision, the revi
40、sion shall apply. ANSI C12.10-2011, American National Standard for Electromechanical Watthour Meters ANSI Z535.4-2011, Product Safety Signs and Labels ANSI/UL 50-2012, Enclosure for Electrical Equipment ANSI/UL 414-2009, Safety Standard for Meter Sockets NEMA 250-2008, Enclosures for Electrical Equi
41、pment (1000 V Maximum) 3 Definitions 3.1 circuit bypass means (bypass): An assembly of parts which, when properly operated, closes the circuit between the line and load jaws. 3.2 continuous-duty current rating: The rating in amperes that a meter socket will carry continuously under stated conditions
42、 without exceeding the allowable temperature rise. A multiposition trough socket has an additional current rating that denotes the maximum ampere capacity of the line buses. 3.3 continuous load: A load where the current continues for 3 hours or more. 3.4 meter socket (socket): An enclosure that has
43、matching jaws to accommodate the bayonet-type (blade) terminals of a detachable watthour meter and has a means of connection for the termination of the circuit conductors. It may be a single-position socket for one meter or a multiposition trough socket for two or more meters. 3.5 meter support: Tha
44、t part of a ringless-type meter socket that positions and supports a detachable watthour meter. 3.6 ringless-type meter socket: A meter socket that has no provision for a socket sealing ring but has other means of holding a detachable watthour meter in place, such as a cover that is secured in place
45、 by a latch. 3.7 ring-type meter socket: A meter socket that has a socket rim. 3.8 socket cover: The removable portion of the enclosure that provides access to the meter socket wiring. 3.9 socket rim: That part of a ring-type meter socket that is required to accommodate the socket sealing ring that
46、holds a detachable watthour meter in place. The socket rim may be a part of the cover that is secured in place by a fastener such as a latch or crossbar. 3.10 socket sealing ring: A ring used to overlap the socket rim and the detachable watthour meter cover ring to hold and provide means for sealing
47、 a detachable watthour meter in place. ANSI C12.7-2014 2 2014 National Electrical Manufacturers Association 4 Electrical Ratings 4.1 Current ratings Continuous duty current ratings of sockets shall include 20, 80, 100, 120, 150, 160, 200, and 320 A. 4.2 Voltage ratings The voltage ratings shall be 3
48、00 V or 600 V. Meter sockets shall be so designed as to be applicable to one or more of the following nominal voltages: Table 1 300 V Rating 120/240 3-wire single phase 208Y/120 3-wire open Y 208Y/120 4-wire three-phase Y 240/120 4-wire three-phase 240 3-wire three-phase Table 2 600 V Rating 480 3-w
49、ire three-phase 480Y/277 4-wire three-phase Y 600 3-wire three-phase 5 Performance Requirements Performance requirements for meter sockets shall be in accordance with applicable performance sections of ANSI/UL 414. 6 Construction Requirements 6.1 Construction and workmanship The watthour meter socket and its components shall be constructed of materials suitable for the particular use. They shall be made and finished with a high degree
