The Siemens 3NJ6314-2AB0.-.... is a SENTRON 3NJ63 switch disconnector with fuses in an in-line design, rated for NH1 fuse links up to 250 A across 4 poles.
The AC23B rating at 500 V governs the real-world motor-switching duty: it handles the high inrush of squirrel-cage motors during start and the occasional plugging or reversing. The NH1 fuse size (250 A) dictates the fuse holder dimensions; verify your existing fuse base accepts NH1 links before specifying.
Compliance documentation
RoHS compliant since 27-09-19. REACH Article 33 duty-to-inform information is available per the current candidate list. Export control classification is AL: N / ECCN: N, meaning no special licensing is required for standard industrial use.