ANSI · American National Standards Institute
The US standards accreditor whose imprimatur turns industry documents into national standards that lenders, insurers, and code officials treat as the governing reference.
Current numbers
0.2S / 0.5S (IEC examples); 0.2 / 0.5 (ANSI examples)AC revenue-meter accuracy-class examples at the POI: IEC 62053-22:2020 (0.2S/0.5S), ANSI C12.1-2026 (0.2/0.5)
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
ATS-2025ANSI/NETA Acceptance Testing Specifications: the current as-installed bar for switchgear, breakers, relays and primary injection