UL 1004-4:2018 PDF Download

UL 1004-4:2018 is a standard that supplements or modifies the requirements outlined in the Standard for Rotating Electrical Machines - General Requirements, UL 1004-1. It specifically focuses on electric generators, also known as alternators, that are used in conjunction with prime movers (such as engines or electric motors) to produce electricity. The standard applies to generators with a rated voltage of 34,000 volts or less.

It's important to note that this standard does not cover stationary or portable generator assemblies, which are covered by UL 2200 (Standard for Stationary Engine Generator Assemblies) and UL 2201 (Standard for Carbon Monoxide (CO) Emission Rate of Portable Generators), respectively. Additionally, it does not cover generators intended for use in hazardous locations, as defined in the National Electrical Code (NEC).

The term "generator" in this context refers to both AC and DC machines.