1、UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION OR DISTRIBUTION WITHOUT PERMISSION FROM UL UL 248-12 Low-Voltage Fuses - Part 12: Class R FusesUL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION OR DISTRIBUTION WITHOUT PERMISSION FROM ULUL COPYRIGHTED MATERIAL NOT AUTHORI
2、ZED FOR FURTHER REPRODUCTION OR DISTRIBUTION WITHOUT PERMISSION FROM UL UL Standard for Safety for Low-Voltage Fuses - Part 12: Class R Fuses UL 248-12 Third Edition, Dated May 13, 2011 Summary of Topics This revision of ANSI/UL 24812 is being issued to reaffirm approval as an American National Stan
3、dard. No changes in requirements are involved. As noted in the Commitment for Amendments statement located on the back side of the title page, UL, CSA, and ANCE are committed to updating this harmonized standard jointly. However, the revision pages dated (June 26, 2015) will not be jointly issued by
4、 UL, CSA, and ANCE as these revision pages only address UL 24812 ANSI approval dates. The new requirements are substantially in accordance with Proposal(s) on this subject dated June 26, 2015. All rights reserved. No part of this publication may be reproduced, stored in a retrieval system, or transm
5、itted in any form by any means, electronic, mechanical photocopying, recording, or otherwise without prior permission of UL. UL provides this Standard as is without warranty of any kind, either expressed or implied, including but not limited to, the implied warranties of merchantability or tness for
6、 any purpose. In no event will UL be liable for any special, incidental, consequential, indirect or similar damages, including loss of prots, lost savings, loss of data, or any other damages arising out of the use of or the inability to use this Standard, even if UL or an authorized UL representativ
7、e has been advised of the possibility of such damage. In no event shall ULs liability for any damage ever exceed the price paid for this Standard, regardless of the form of the claim. Users of the electronic versions of ULs Standards for Safety agree to defend, indemnify, and hold UL harmless from a
8、nd against any loss, expense, liability, damage, claim, or judgment (including reasonable attorneys fees) resulting from any error or deviation introduced while purchaser is storing an electronic Standard on the purchasers computer system. The requirements in this Standard are now in effect, except
9、for those paragraphs, sections, tables, gures, and/or other elements of the Standard having future effective dates as indicated on this transmittal notice. The prior text for requirements that have been revised and that have a future effective date are located after the Standard, and are preceded by
10、 a SUPERSEDED REQUIREMENTS notice. AUGUST 18, 2015 UL 248-12 tr1UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION OR DISTRIBUTION WITHOUT PERMISSION FROM UL AUGUST 18, 2015 UL 248-12 tr2 No Text on This PageUL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION OR DISTRIBUTION
11、 WITHOUT PERMISSION FROM UL Association of Standardization and Certication NMX-J-009/248/12-ANCE Second Edition Canadian Standards Association CSA C22.2 No. 248.12-11 Third Edition Underwriters Laboratories Inc. UL 248-12 Third Edition Low-Voltage Fuses Part 12: Class R Fuses May 13, 2011 (Title Pag
12、e Reprinted: August 18, 2015) ANSI/UL 248-12-2011 (R2015)UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION OR DISTRIBUTION WITHOUT PERMISSION FROM UL Commitment for Amendments This standard is issued jointly by the Association of Standardization and Certication (ANCE), the Canadian Sta
13、ndards Association (operating as “CSA Group”), and Underwriters Laboratories Inc. (UL). Comments or proposals for revisions on any part of the standard may be submitted to ANCE, CSA Group, or UL at anytime. Revisions to this standard will be made only after processing according to the standards deve
14、lopment procedures of ANCE, CSA Group, and UL. CSA Group and UL will issue revisions to this standard by means of a new edition or revised or additional pages bearing their date of issue. ANCE will incorporate the same revisions into a new edition of the standard bearing the same date of issue as th
15、e CSA Group and UL pages. Copyright 2011 ANCE Rights reserved in favor of ANCE. ISBN 978-1-55491-638-2 2011 CSA Group All rights reserved. No part of this publication may be reproduced in any form whatsoever without the prior permission of the publisher. CSA Standards are subject to periodic review,
16、 and suggestions for their improvement will be referred to the appropriate committee. To submit a proposal for change to CSA Standards, please send the following information to inquirescsa.ca and include Proposal for change in the subject line: Standard designation (number); relevant clause, table,
17、and/or gure number; wording of the proposed change; and rationale for the change. To purchase CSA Standards and related publications, visit CSAs Online Store at www.ShopCSA.ca or call toll-free 1-800-463-6727 or 416-747-4044. Copyright 2015 Underwriters Laboratories Inc. ULs Standards for Safety are
18、 copyrighted by UL. Neither a printed nor electronic copy of a Standard should be altered in any way. All of ULs Standards and all copyrights, ownerships, and rights regarding those Standards shall remain the sole and exclusive property of UL. This ANSI/UL Standard for Safety consists of the Third E
19、dition including revisions through August 18, 2015. The most recent designation of ANSI/UL 248-12 as an American National Standard (ANSI) occurred on August 18, 2015. ANSI approval for a standard does not include the Cover Page, Transmittal Pages, Title Page (front and back), or the Preface. Comment
20、s or proposals for revisions on any part of the Standard may be submitted to UL at any time. Proposals should be submitted via a Proposal Request in ULs On-Line Collaborative Standards Development System (CSDS) at http:/. To purchase UL Standards, visit Comm 2000 at http:/m- or call toll-free 1-888-
21、853-3503.UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION OR DISTRIBUTION WITHOUT PERMISSION FROM UL CONTENTS Preface .4 1 General 6 1.1 Scope .6 4 Classication .6 5 Characteristics 6 5.2 Voltage rating 6 5.3 Current rating 6 5.5 Interrupting rating .7 5.6 Peak let-through current and
22、 clearing I 2 t characteristics .7 7 Construction 8 7.1 Dimensions 8 8 Tests .12 8.2 Verication of temperature rise and current-carrying capacity .12 8.3 Verication of overload operation 13 8.4 Verication of operation at rated voltage .13 8.5 Verication of peak let-through current and clearing I 2 t
23、 characteristics .14 MAY 13, 2011 NMX-J-009/248/12-ANCE CSA C22.2 NO. 248.12-11 UL 248-12 3UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION OR DISTRIBUTION WITHOUT PERMISSION FROM UL Preface This is the harmonized ANCE, CSA, and UL standard for Low-Voltage Fuses Part 12: Class R Fuses
24、. It is the second edition of NMX-J-009/248/12-ANCE, the third edition of CSA C22.2 No. 248.12-11, and the third edition of UL 248-11. This edition of NMX-J-009-248/12-ANCE cancels the previous edition published in 2000. This edition of CSA C22.2 No. 248.12-11 supersedes the previous edition publish
25、ed in 2000. This harmonized standard was prepared by the Association of Standardization and Certication (ANCE), the Canadian Standards Association (CSA), and Underwriters Laboratories Inc., (UL). This Standard is considered suitable for use for conformity assessment within the stated scope of the St
26、andard. The present Mexican Standard was developed by the CT 32 from the Comite de Normalizacion de la Asociacion de Normalizacion y Certicacion, A.C., CONANCE, with the collaboration of the fuse manufacturers and users. This standard was reviewed by the CSA Subcommittee on Fuses and Fuseholders, un
27、der the jurisdiction of the CSA Technical Committee on Industrial Products and the CSA Strategic Steering Committee on Requirements for Electrical Safety, and has been formally approved by the CSA Technical Committee. This standard has been approved by the American National Standards Institute (ANSI
28、) as an American National Standard. A UL standard is current only if it incorporates the most recently adopted revisions, all of which are itemized on the transmittal notice that accompanies the latest set of revised requirements. Where reference is made to a specic number of samples to be tested, t
29、he specied number is to be considered a minimum quantity. Note: Although the intended primary application of this standard is stated in its scope, it is important to note that it remains the responsibility of the users of the standard to judge its suitability for their particular purpose. Level of H
30、armonization This standard is published as an identical standard for ANCE, CSA, and UL. An identical standard is a standard that is exactly the same in technical content except for national differences resulting from conicts in codes and governmental regulations. Presentation is word for word except
31、 for editorial changes. Interpretations The interpretation by the standards development organization of an identical or equivalent standard is based on the literal text to determine compliance with the standard in accordance with the procedural rules of the standards development organization. If mor
32、e than one interpretation of the literal text has been identied, a revision is to be proposed as soon as possible to each of the standards development organizations to more accurately reect the intent. MAY 13, 2011 NMX-J-009/248/12-ANCE CSA C22.2 NO. 248.12-11 UL 248-12 4UL COPYRIGHTED MATERIAL NOT
33、AUTHORIZED FOR FURTHER REPRODUCTION OR DISTRIBUTION WITHOUT PERMISSION FROM UL ANCE Effective Date The effective date for ANCE will be announced through the Diario Ocial de la Federacin (Official Gazette) and is indicated on the cover page. CSA Effective Date The effective date for CSA International
34、 will be announced through CSA Informs or a CSA certication notice. UL Effective Date As of May 13, 2011 all products Listed or Recognized by UL must comply with the requirements in this standard. A UL effective date is one established by Underwriters Laboratories Inc. and is not part of the ANSI ap
35、proved standard. MAY 13, 2011 NMX-J-009/248/12-ANCE CSA C22.2 NO. 248.12-11 UL 248-12 5UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION OR DISTRIBUTION WITHOUT PERMISSION FROM UL Low-Voltage Fuses Part 12: Class R fuses 1 General NOTE This Part is intended to be read together with the
36、 Standard for Low-Voltage Fuses Part 1: General Requirements, hereafter referred to as Part 1. The numbering of the Clauses in this Part corresponds to like numbered Clauses in Part 1. The requirements of Part 1 apply unless modied by this Part. For Clauses not shown below, refer to the Standard for
37、 Low-Voltage Fuses Part 1: General Requirements, NMX-J-009/248/1-ANCE CAN/CSA C22.2 No. 248.1-11 UL 248-1. 1.1 Scope This Part applies to Class R fuses rated 600 A or less and either 250 or 600 V ac. DC ratings are optional. 4 Classication Class R fuses are non-renewable and current-limiting, with a
38、n interrupting rating of 200,000 A. Class R fuses are divided into sub-classes RK1 and RK5 and are physically interchangeable for the same current and voltage ratings. Class RK1 fuses have lower specied maximum peak let-through current and clearing I 2 t characteristics. Each of the voltage ratings,
39、 250 and 600 V ac, is divided into six body sizes. The maximum current rating, I n , for each size is specied in this Standard. Time-delay ratings are optional. 5 Characteristics 5.2 Voltage rating For AC, the rating shall be 250 or 600 V ac in accordance with dimensions shown in Figures A and B. Th
40、e DC voltage rating may be different from the AC rating. 5.3 Current rating Refer to Figure A for range of current ratings in each body size for each voltage rating. MAY 13, 2011 NMX-J-009/248/12-ANCE CSA C22.2 NO. 248.12-11 UL 248-12 6UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION
41、OR DISTRIBUTION WITHOUT PERMISSION FROM UL 5.5 Interrupting rating For AC, 200,000 A, or 300,000 A at the manufacturers option (300,000 not applicable in Mexico). For DC, the preferred ratings are 10,000, 20,000, 50,000, 100,000, 150,000, 200,000, or 300,000A. 5.6 Peak let-through current and cleari
42、ng I 2 t characteristics Maximum values of peak let-through current and clearing I 2 t Class RK1 and Class RK5 fuses are given in Table A (see 8.5.3). Peak let-through currents shall not exceed the levels dened by the appropriate Let Through Function specied in Table A, as veried through measurement
43、 of peak let-through currents at 25, 50, 100, 200, and, if applicable, 300 kA. Clearing I 2 t values recorded shall not exceed the limits specied in Table A as veried through measurement of clearing I 2 t values at 25, 50, 100, 200, and, if applicable, 300 kA. Table A Maximum peak let-through curren
44、t and clearing I 2 t for Class R fuses Current rating I n ,A Between threshold and 25 kA At 50 kA At 100 kA At 200 kA At 300 kA, if applicable Peak Let- through Function a Peak let- through current, kA I 2 t, ampere- squared seconds 31 0 3 Peak let- through current, kA I 2 t, ampere- squared seconds
45、 31 0 3 Peak let- through current, kA I 2 t, ampere- squared seconds 31 0 3 Peak let- through current, kA I 2 t, ampere- squared seconds 31 0 3 Peak let- through current, kA I 2 t, ampere- squared seconds 31 0 3 Class RK1 0 - 30 6 10 6 10 8.7 10 12 11 16 13 Y = 3.71E- 02X + 5E+03 31 - 60 9 40 10 40
46、12 40 16 50 20 60 Y = 0.04X + 8000 61 - 100 13 100 14 100 16 100 20 100 24 120 Y = 0.04X + 12000 101 - 200 16 400 18 400 22 400 30 400 38 480 Y = 8E-02X + 1.4E+04 201 - 400 32 1,200 33 1,200 35 1,200 50 1,600 79 1,920 Y = 7.3E- 07X 2 7E-02X + 3.47E+04 401 - 600 43 3,000 45 3,000 50 3,000 70 4,000 10
47、4 4,800 Y = 6.7E- 07X 2 + 4.33E+04 Class RK5 MAY 13, 2011 NMX-J-009/248/12-ANCE CSA C22.2 NO. 248.12-11 UL 248-12 7 Table A Maximum peak let-through current and clearing I 2 t for Class R fuses Continued on Next PageUL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION OR DISTRIBUTION WITH
48、OUT PERMISSION FROM UL Table A Maximum peak let-through current and clearing I 2 t for Class R fuses Continued Current rating I n ,A Between threshold and 25 kA At 50 kA At 100 kA At 200 kA At 300 kA, if applicable Peak Let- through Function a Peak let- through current, kA I 2 t, ampere- squared sec
49、onds 31 0 3 Peak let- through current, kA I 2 t, ampere- squared seconds 31 0 3 Peak let- through current, kA I 2 t, ampere- squared seconds 31 0 3 Peak let- through current, kA I 2 t, ampere- squared seconds 31 0 3 Peak let- through current, kA I 2 t, ampere- squared seconds 31 0 3 0 - 3 01 15 01 15 01 15 01 45 02 16 0Y = 2.0E- 07X 2 - 3E-02X + 1.2E+04 31 - 60 20 200 20 200 21 200 26 200 35 240 Y = 2.0E- 07X 2 - 1E-
