Please note: All interim revisions for this edition available at time of your purchase will be included.

UL 1004-4 is intended to be read together with the Standard for Rotating Electrical Machines - General Requirements, UL 1004-1. The numbering of the Sections in this Standard corresponds to the like numbered Sections in UL 1004-1. The numbering of the paragraphs are unique to this Standard, and do not directly correspond to the like numbered paragraphs in UL 1004-1. The requirements in this Standard supplement or amend the requirements in UL 1004-1. The requirements of UL 1004-1 apply unless modified by this Standard. For Sections not shown, refer to the Standard for Rotating Electrical Machines - General Requirements, UL 1004-1.

This Standard covers electric generators, sometimes referred to as generator heads, which, when coupled with prime movers, such as engines or electric motors, are used to produce electricity. This Standard covers generators (DC machines) and alternators (AC machines) rated 7,200 volts or less.

This Standard does not cover stationary or portable generator assemblies, which are respectively covered under the Standard for Stationary Engine Generator Assemblies, UL 2200, and the Outline for Portable Engine-Generator Assemblies, Subject 2201.

This Standard does not cover generators intended for use in hazardous locations as defined in the National Electrical Code, NFPA 70.The National Electrical Code® and NEC® are registered trademarks of the National Fire Protection Association, Inc., Quincy, MA 02169.

In the context of this document, the term generators shall be understood to apply to both AC and DC machines.