Switch disconnector with fuses — 250 A, 4-pole, AC23B
The Siemens 3NJ6314-2AC0.-.... is a SENTRON 3NJ63 switch disconnector with fuses in an in-line, pluggable NH1 design rated 250 A, 4-pole, AC23B 500V, with a 55 kA rated short-circuit making capacity at AC500V. The AC23B duty class means it is sized for switching motor loads and other highly inductive circuits — the rating that governs real-world fit on a motor feeder or distribution branch, not the thermal current alone. The integrated EFM 20 fuse monitoring provides a signal contact for blown-fuse indication, which saves a maintenance walk when a fuse clears on a remote panel.