scope:

PREFACE

This is the harmonized ANCE, CSA Group, and UL standard for Molded-Case Circuit Breakers, Molded-Case Switches, and Circuit-Breaker Enclosures. It is the fifth edition of NMX-J-266-ANCE, the fourth edition of CSA C22.2 No. 5, and the thirteenth edition of UL 489. This harmonized standard has been jointly revised on April 22, 2019. For this purpose, CSA Group and UL are issuing revision pages dated April 22, 2019, and ANCE is issuing a new edition dated April 22, 2019.

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, 121A, Molded Case Circuit Breakers 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 CDI Control y Distribución Industrial from the Comite de Normalizacion de la Asociacion de Normalizacion y Certificacion, A.C., CONANCE, with the collaboration of the circuit breaker manufacturers and users.

This standard was reviewed by the CSA Subcommittee on Molded Case Circuit Breakers, Molded Case Switches and Circuit Breaker Enclosures 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.