UL 1066

Low-Voltage AC and DC Power Circuit Breakers Used in Enclosures

UL 1066

1 Scope

1.1 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.

Section 1 effective April 13, 2012

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 current limiters or fuses.

1.3 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.

1.4 These requirements apply to general purpose type low-voltage dc power circuit breakers.

1.5 These requirements cover equipment intended for use in ordinary locations in accordance with the National Electrical Code, ANSI/NFPA 70.

1.6 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.

1.7 These requirements cover equipment rated 600 V or less nominal, 635 V maximum ac and 300 V maximum dc.

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.