The Schneider Electric C40F44B400 is a ComPacT NSX400F molded case circuit breaker (MCCB) rated 400 A at 40 °C, with a 4-pole configuration and an electronic MicroLogic 4.3 AB trip unit. Its breaking capacity is 40 kA Icu at 240 V AC per IEC 60947-2, with a stepped curve down to 10 kA at 690 V AC — the 36 kA at 415 V AC is the figure most relevant for European 400 V distribution panels.
The F breaking capacity code (36 kA at 415 V AC) places this MCCB in the middle tier of the NSX range — above the B (25 kA) and below the N (50 kA) or H (70 kA) frames. For a 400 A feeder in a 400 V industrial panel, 36 kA Icu gives headroom for most transformer-fed installations without stepping up to a larger frame. The UL 60947-4-1 ratings (85 kA at 240 V, 35 kA at 480 V) confirm suitability for North American motor branch circuits as well.
The earth-leakage function is integrated, so no external RCD or toroid is needed for ground-fault detection.
IP40 enclosure protection means it's suitable for clean indoor panels but not washdown areas.