current North American SPD product standard (UL 1449 Ed. 5, published 2021-01-08; last revised and ANSI-approved 2025-10-21); NEC requires SPDs to be listed for their intended application
UL 1449 5th Ed.observed
| Value kind | observed — Reported measurements, counts, and specifications keep the precision and scope stated by their source; an exact specification is not treated as a range. |
|---|---|
| Scope | The published UL 1449 scope names AC and PV DC applications; a non-PV 800 VDC SPD needs a listing or evaluation that expressly covers that application. |
| As of | 2025-10-21 |
| Source | UL Standards; NEMA Surge · UL 1449 Edition 5 published 2021-01-08; latest revision and ANSI approval 2025-10-21. Published scope: 50/60 Hz AC circuits up to 1,000 V and PV applications up to 1,500 V DC. NEC §242.6: an SPD shall be a listed device. |
| Review | checking…review by 2026-12-15 · slow cadence |
| Recorded changes | last 2026-10-13 · 2 revisions tracked |
| Claim id | current-north-american-spd-listing-basis-ansi |
Where the guide uses it
← Full numbers register — every date-stamped figure in the guide, with revision history.