Preface 

This is the harmonized CSA Group and UL standard for Circuit Breakers up to 1000 V AC and 1500 V DC Used in Enclosures. It is the second edition of CSA C22.2 No. 268:22 and the fifth edition of UL 1066. This second edition of CSA C22.2 No. 268 supersedes the previous edition published April 13, 2012. This fifth edition of UL 1066 supersedes the previous edition published April 13, 2012. This harmonized standard was prepared by the CSA Group and Underwriters Laboratories Inc. (UL). The efforts and support of the Technical Harmonization Committee for Power 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. This standard was reviewed by the CSA Subcommittee on Low Voltage Power Circuit Breakers, 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 developed in compliance with the Standards Council of Canada requirements for National Standards of Canada. It has been published as a National Standard of Canada by CSA Group. 

Scope 

1.1 These requirements apply to low-voltage AC power circuit breakers as follows: a) Stationary-mounted or drawout-mounted types, b) 2-pole, 3-pole, and 4-pole constructions, c) Manually operated or power operated, and d) With or without electromechanical or solid-state type trip device. 

1.2 These requirements apply to drawout-mounted type low-voltage AC integrally fused power circuit breakers, consisting of low-voltage AC power circuit breakers with integral fuses. 

1.3 These requirements apply to low-voltage AC fuse draw-outs consisting of fuses in a drawout assembly intended to be connected in series with a low-voltage AC power circuit breaker to form a fused circuit breaker. 

1.4 These requirements apply to general purpose type DC power circuit breakers. 

1.5 These requirements apply to equipment rated 1000 V or less nominal, 1058 V maximum AC and 1500 V maximum DC. 

1.6 These requirements apply to equipment intended for use in ordinary locations in accordance with Annex A, Ref. No. 1. 

1.7 These requirements are intended to supplement and be used in conjunction with the: a) Standard for Low-Voltage AC Power Circuit Breakers Used In Enclosures, IEEE C37.13 (see Annex A, Ref. No. 7), b) Standard for DC (3200 V and below) Power Circuit Breakers Used in Enclosures, IEEE C37.14 (see Annex A, Ref. No. 8), c) Standard for Metal-Enclosed Low-Voltage (1000 Vac and below, 3200 Vdc and below) Power Circuit Breaker Switchgear, IEEE C37.20.1 (see Annex A, Ref. No. 9), d) Test Procedures for Switchgear – Low-Voltage AC Power Circuit Breakers Used In Enclosures, ANSI C37.50 (see Annex A, Ref. No. 10), and e) Conformance Test Procedures for Switchgear – Metal-Enclosed Low-Voltage AC Power Circuit Breaker Switchgear Assemblies, ANSI C37.51 (see Annex A, Ref. No. 11). 

1.8 This Standard does not apply to molded-case circuit breakers. 

1.9 These circuit breakers are intended for installation in circuit breaker enclosures, switchboards (switchgear), panelboards, and the like. Drawout-mounted devices are intended for use with specific adapters or receiving equipment. The acceptability of the combination of a circuit breaker with respect to any overall enclosure will be determined when the complete product is considered.