CSA C22.2 No. 248.12:11

National Standard of Canada

(reaffirmed 2020)

Low-voltage fuses — Part 12: Class R fuses

REVISED SEPTEMBER 2020

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Revision History

CSA C22.2 No. 248.12:11, Low-voltage fuses — Part 12: Class R fuses

National Standard of Canada — September 2020

Outside front cover, National Standard of Canada text, and title page.

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®A trademark of the Canadian Standards Association, operating as “CSA Group”

National Standard of Canada

CSA C22.2 No. 248.12:11

Low-voltage fuses — Part 12: Class R fuses

®A trademark of the Canadian Standards Association, operating as “CSA Group”

ICS 29.120.50

ISBN 978-1-55491-638-2

Association of Standardization and Certification NMX-J-009/248/12-ANCE

Third 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 Page Reprinted: December 20, 2017)

ANSI/UL 248-12-2017

Association of Standardization and Certification NMX-J-009/248/12-ANCE

Third 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 Page Reprinted: December 20, 2017)

ANSI/UL 248-12-2017

DECEMBER 20, 2017 NMX-J-009/248/12-ANCE  CSA C22.2 NO. 248.12-11  UL 248-12 3

CONTENTS

Preface 4

1 General 5

1.1 Scope 5

4 Classification 5

1. Characteristics 5

   1. Voltage rating 5

   2. Current rating 5

1. Interrupting rating 7

2. Peak let-through current and clearing I2t characteristics 7

1. Construction 8

   7.1 Dimensions 8

2. Tests 12

1. Verification of temperature rise and current-carrying capacity 12

2. Verification of overload operation 13

3. Verification of operation at rated voltage 13

4. Verification of peak let-through current and clearing I2t characteristics 14

4 NMX-J-009/248/12-ANCE  CSA C22.2 NO. 248.12-11  UL 248-12 DECEMBER 20, 2017

Preface

This is the harmonized ANCE, CSA Group, and UL standard for Low-Voltage Fuses - Part 12: Class R Fuses. It is the third 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 supersedes the previous edition published in 2006. This edition of CSA C22.2 No. 248.12-11 supersedes the previous edition published in 2000.

This harmonized standard was prepared by the Association of Standardization and Certification (ANCE), CSA Group and Underwriters Laboratories Inc., (UL). The efforts and support of the Technical Harmonization Subcommittee, THC 32B, Fuses and Fuseholders, on the Harmonization of Electrotechnical Standards of the Nations of the Americas (CANENA), are gratefully acknowledged.

This Standard is considered suitable for use for conformity assessment within the stated scope of the Standard.

The present Mexican Standard was developed by the CT 32 from the Comite de Normalizacion de la Asociacion de Normalizacion y Certificacion, A.C., CONANCE, with the collaboration of the fuse manufacturers and users.

This standard was reviewed by the CSA Subcommittee on Fuses and Fuseholders, under 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) as an American National Standard.

Application of Standard

Where reference is made to a specific number of samples to be tested, the specified number is to be considered a minimum quantity.

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Level of Harmonization

This standard is published as an identical standard for ANCE, CSA Group and UL.

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