NEC · National Electrical Code
NFPA 70, the US electrical installation code — the code path new distribution schemes such as 800 VDC and SSTs must clear before scale deployment.
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
UL 1449 5th Ed.current North American SPD product standard (UL 1449 Ed. 5, 2021; ANSI-approved revision 2025-10-21); NEC requires listed SPDs