Fuse switch disconnector, 3-pole switchable, gR 3 and 2 I=630A, U=690V Flat connection M12, with electronic fuse monitoring The 3NJ4 fuse switch disconnectors for low-voltage distribution. The 1- or 3-pole switchable 3NJ4 fuse switch disconnectors can be used in low-voltage distributors, network and transformer stations and cable distribution cabinets. The Siemens 3NJ4 fuse switch disconnectors are characterized above all by: 1. Compliance with the provisions of IEC/EN 60439-1 and IEC/EN 60947-3. 2. Voltage levels up to AC 690 V. 3. Parking position for maintenance work. 4. Vertical and horizontal installation position. 5. Climate resistance. 6. Protection class IP30 with closed handle inserts, IP10 with open handle inserts.