The Schneider Electric MGN60905 is a C60N Multi9 miniature circuit breaker — 4 poles, 6 A rated current at 50 °C, C-curve, thermal-magnetic trip. It carries a 20 kA Icu breaking capacity at 240 V AC phase-to-phase (EN/IEC 60947-2), which drops to 10 kA at 415 V AC and 6 kA at 440 V AC. That 20 kA figure at 240 V is the headline fault-interruption rating; the 415 V and 440 V deratings tell you where the part sits in a selectivity study for a 400 V three-phase distribution board.
Selectivity and coordination
The C-curve magnetic trip fires at 8.5 x In (±20 %), so this 6 A breaker holds through motor inrush up to roughly 51 A before the solenoid pulls in. That puts it squarely in the middle of the C-curve band — suitable for mixed resistive-inductive loads like contactor coils, small transformers, and lighting banks where the inrush exceeds a B-curve's 3-5x threshold but doesn't need the D-curve's 10-20x headroom. The service breaking capacity (Ics) is 75 % of Icu at each voltage level — 15 kA at 240 V, 7.5 kA at 415 V, 4.5 kA at 440 V — meaning after clearing a fault at those levels the breaker remains functional, not just safe.
The 4-pole body is 81 mm tall and 73 mm deep — standard for a four-module C60N. Strip length is 14 mm. IP20 finger-safe protection on the front face; pollution degree 3 per EN/IEC 60947-2, so it's rated for the conductive-dust environment typical of industrial panels.