UL Standard for Safety Low-Voltage AC and DC Power Circuit Breakers Used in Enclosures
|Publication Date:||30 May 1997|
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, ANSIINFPA 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.