UL 489:2019 PDF Download

UL 489:2019 is a standard that specifies the requirements for molded-case circuit breakers, molded-case switches, and circuit-breaker enclosures. The standard covers various types of circuit breakers, including molded-case circuit breakers, circuit breaker and ground-fault circuit-interrupters, fused circuit breakers, high-fault protectors, and high-fault modules. These circuit breakers are designed to provide protection for service entrance, feeder, and branch circuits in accordance with the National Installation Codes.

In addition to circuit breakers, the standard also covers molded-case switches and fused molded-case switches. The devices covered by the standard are rated at 1000 volts AC and 1500 volts DC or lower, with current ratings up to 6000 amperes. They can be installed in overall enclosures or as parts of other devices such as panelboards, and the acceptability of the combination will be determined during investigation.

The standard also includes provisions for circuit-breaker enclosures and accessory devices intended for use with the circuit breakers and switches mentioned above. However, it excludes coverage of low-voltage power circuit breakers and supplementary protectors.

Furthermore, the standard contains supplements that specify additional requirements for specific applications. These supplements cover molded-case circuit breakers for marine use, naval use, uninterruptible power supply use, classified circuit breakers, software in programmable components, additional tests for circuit breakers with electronic overcurrent protection, electromagnetic compatibility (EMC) requirements and test methods, and molded-case circuit breakers with additional motor overload protection. These supplements provide guidance and additional requirements for circuit breakers used in specific contexts or applications.