UL Standard for Safety Low-Voltage AC and DC Power Circuit Breakers Used in Enclosures (Third Edition; Reprint with Revisions Through and Including October 05@ 2009)
These requirements cover low-voltage ac power circuit breakers as follows: a) Stationary-mounted or drawout-mounted types@ b) 2-pole and 3-pole constructions@ c) Manually operated or power operated@ and d) With or without electromechanical or solid-state type trip device. 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 current limiters or fuses. These requirements apply to low-voltage ac fuse draw-outs consisting of current limiters or 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. These requirements apply to general purpose type low-voltage dc power circuit breakers. These requirements cover equipment intended for use in ordinary locations in accordance with the National Electrical Code@ ANSI/NFPA 70. 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@ ANSI/IEEE C37.13-1990@ b) Standard for Low-Voltage DC Power Circuit Breakers Used In Enclosures@ ANSI/IEEE C37.14-1993@ c) Standard for Metal-Enclosed Low-Voltage Power Circuit-Breaker Switchgear@ ANSI/IEEE C37.20.1-1993@ d) Test Procedures for Low-Voltage AC Power Circuit Breakers Used In Enclosures@ ANSI C37.50-1989 (R1995)@ and e) Conformance Testing of Metal-Enclosed Low-Voltage AC Power Circuit Breaker Switchgear Assemblies@ ANSI C37.51-1989 (R1995). These requirements cover equipment rated 600 V or less nominal@ 635 V maximum ac and 300 V maximum dc. This Standard does not apply to molded-case circuit breakers. 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. A product that contains features@ characteristics@ components@ materials@ or systems new or different from those covered by the requirements in this Standard@ and that involves a risk of fire@ electric shock@ or injury to persons shall be evaluated using the appropriate additional component and end-product requirements as determined necessary to maintain the acceptable level of safety as originally anticipated by the intent of this Standard. A product whose features@ characteristics@ components@ materials@ or systems conflict with specific requirements or provisions of this Standard cannot be judged to comply with this Standard. Where considered appropriate@ revision of requirements shall be proposed and adopted in conformance with the methods employed for development@ revision@ and implementation of this Standard.