UL Standard for Safety Low-Voltage AC and DC Power Circuit Breakers Used in Enclosures
|Publication Date:||13 April 2012|
These requirements cover 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.
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, IEEE C37.13,
b) Standard for Low-Voltage DC Power Circuit Breakers Used In Enclosures, IEEE C37.14,
c) Standard for Metal-Enclosed Low-Voltage Power Circuit-Breaker Switchgear, IEEE C37.20.1,
d) Test Procedures for Switchgear - Low-Voltage AC Power Circuit Breakers Used In Enclosures, ANSI C37.50, and
e) Conformance Test Procedures for Switchgear - Metal-Enclosed Low-Voltage AC Power Circuit Breaker Switchgear Assemblies, ANSI C37.51.
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.