UL 1004-9:2021 PDF Download

UL 1004-9:2021 is a standard that complements the requirements outlined in the Standard for Rotating Electrical Machines - General Requirements, UL 1004-1. It specifically applies to form wound and medium voltage rotating electrical machines, including both AC and DC machines.

The standard covers field-installed machines with form wound windings rated between 460 V and up to 34,000 V. It also applies to field-installed machines with random wound windings rated above 1,000 V and up to 7,200 V.

It's important to note that machines intended for use in hazardous locations may have additional requirements specified in the National Electrical Code, NFPA 70. Additionally, the standard does not cover sealed (hermetic type) motor-compressor parts, which are evaluated under a separate standard for household appliances.

Furthermore, it's worth mentioning that special generators, such as hydrogen-cooled generators rated 10 MVA and above, are not covered by this standard. These generators have their specific requirements outlined in IEEE and IEC standards.