Selective main MCB for 400 V distribution
Rated at 50 A (AC) with a 25 kA breaking capacity, this 3-pole unit occupies 6 width units on a standard 35 mm DIN rail. The saddle terminals accept conductors from 2.5 mm² minimum up to 50 mm² maximum — sized for the incoming feeder cable, not branch circuits. The 6 kV rated surge voltage resistance (overvoltage category IV) confirms it's built for the main incoming supply position where lightning-induced surges are most severe.
Mechanical endurance and environmental tolerance
Rated for 20 000 mechanical switching cycles typical, with shock resistance of 30 g (3 impacts, 11 ms duration) and vibration resistance of 2 g per IEC 60068-2-6. The switch position indicator shows OFF = green, ON = red — a standard visual cue for panel walk-downs.