Summary of Topics s991_3_sum.htmlSummary of Topics
This revision of UL 991 dated December 27, 2024 includes the following changes in requirements:
– Clarification of requirements if no critical components are found in a failure mode and effects analysis: Figure 6.1, 6.3, and 23.4.
– Alternate test methods for the environmental stress tests: 11.1.1, 12.1, 13.1, 14.1.1, 15.1.1 – 15.1.4, 15.1.1A, 15.2.1A, 15.2.2A, 15.2.3A, 15.2.4A.