UL 1446 PDF

 

1 Scope

1.1 These requirements cover test procedures to be used in the evaluation of Class 120(E) or higher electrical insulation systems (EIS) for use in the United States, and Class 130(B) or higher EIS for use in Canada, where the thermal factor is the dominating aging factor. These requirements also cover the investigation of the substitution of non-electrical insulating materials (NIM) components of insulation in a previously evaluated insulation system and also the test procedures to be used in the evaluation of magnet wire coatings, magnet wires, and varnishes.

1.2 These requirements for the evaluation of an EIS do not establish thermal ratings for/or alter established thermal ratings for individual components.

1.3 These requirements do not cover insulation systems exposed to radiation or operating in oils, refrigerants, soaps, or other media that potentially degrade insulating materials.

1.4 When any performance aspect of an end-product requirement is not covered by this standard, the applicable standard shall be used.

1.5 These requirements do not cover electrical insulation systems where transient overvoltages or partial discharge are present. Such electrical insulation systems shall be evaluated to the appropriate standard for the application. Such standards include, but are not limited to the following:

1. a) IEEE C57.12.60;
2. b) IEC 60034-18-31; or
3. c) IEEE 1776.

 

Summary of Topics

This reaffirmation of ANSI/CAN/UL 1446 dated July 24, 2025 is being issued to update the title page to reflect the latest ANSI and SCC approval dates as a Reaffirmed American National Standard (ANS) and National Standard of Canada (NSC). No changes in requirements are involved.