UL · Underwriters Laboratories
The safety-certification body whose listing makes equipment routinely acceptable to code officials and insurers; unlisted gear waits, however good its engineering case.
Current numbers
NEC 2029 (partial, forecast); UL certification pathway openNEC 2029 expected to add partial 800 VDC provisions (SemiAnalysis); UL opened an MV SST certification program in September 2026
250-1,200 A (UL)UL maxima: PowerWave 2 track 1,000 A, Starline T5 track 1,200 A, enclosed Series HP 6,000 A
UL 9540A, 6th edition (published March 2026)UL 9540A sixth edition, published March 13, 2026; vent-gas ignition and large-scale fire testing