The Siemens 3NJ6303-4AC0.-.... is a SENTRON 3NJ63 switch disconnector with fuses — a 3-pole, 160 A rated unit built for motor drive isolation and fault protection in industrial power distribution. The in-line design with pluggable NH00 fuse holders and integrated EFM 20 fuse monitoring gives a visual and electrical signal when a fuse blows, cutting downtime on a motor drive line.
RoHS compliant since 27 September 2019; REACH candidate list information is available on request.
The pluggable NH00 fuse carriers mean fuse replacement is tool-less — the holder pulls out, the fuse swaps, and it clicks back in without disturbing the line-side wiring. AC23A duty rating covers motor switching, so this unit is sized for a 160 A motor load on a 500 V three-phase supply — common for pumps, fans, and compressors in a control panel. The EFM 20 monitoring module outputs a signal on fuse failure; wire that back to a PLC digital input for a remote blown-fuse alarm instead of walking the panel.