UL 1558:2019 PDF Download

The UL 1558:2019 standard specifies requirements for metal-enclosed power circuit breaker switchgear assemblies. These assemblies contain various components such as low-voltage power circuit breakers, switches, control devices, instrumentation and metering equipment, and protective and regulating equipment. The standard is applicable for use in ordinary locations as defined by the National Electrical Code.

The purpose of this standard is to supplement and be used in conjunction with ANSI C37.20.1, which is the Standard for Metal-Enclosed Low Voltage Power Circuit Breaker Switchgear. It also complements ANSI C37.51, the Standard for Conformance Testing of Metal-Enclosed Low-Voltage AC Power Circuit Breaker Switchgear Assemblies. Together, these standards provide comprehensive guidelines for the design, construction, and testing of metal-enclosed low-voltage power circuit breaker switchgear.

The UL 1558:2019 standard applies to equipment with a nominal voltage rating of 1000 V AC or less, with a maximum voltage rating of 1058 V AC. It ensures that the switchgear assemblies meet the necessary safety and performance requirements to operate effectively and reliably within their intended applications. Compliance with this standard helps to ensure the safe operation of electrical systems and protect against potential hazards.