The C40F34V400 is a 3-pole ComPacT NSX400F earth-leakage circuit breaker from Schneider Electric, rated 400 A at 40 °C with a MicroLogic 4.3 electronic trip unit. The 36 kA Icu at 415 V AC (per EN/IEC 60947-2) is the breaking capacity that governs most European 400 V distribution panels — it tells you this breaker safely interrupts a fault up to 36 kA without failing, which is the figure a panel builder uses for SCCR coordination downstream. The 400 A trip rating means it protects a 400 A feeder or a large motor control center bus; the electronic trip unit gives adjustable long-time (L), short-time (So), instantaneous (I), and earth-leakage (R) protection curves, so you set the trip thresholds to the load, not the other way around. Integrated earth-leakage protection (R function) is built into the trip unit — no external RCD module needed. The 20-minute thermal memory before and after tripping means the breaker remembers the thermal state of the conductors even after a short interruption, preventing nuisance re-closure on a still-hot circuit. Mounting is backplate, horizontal or vertical, with front connections top and bottom; the 140 mm width and 255 mm height fit standard ComPacT NSX cutouts.
The F breaking capacity code delivers 36 kA Icu at 415 V AC, but the same breaker is rated 40 kA at 240 V, 30 kA at 440 V, 25 kA at 500 V, 20 kA at 525 V, and 10 kA at 690 V.
Panel integration and environmental ratings
IP40 front face (finger-safe against tools >1 mm) and IK07 impact resistance per IEC 62262 — suitable for enclosed distribution boards where incidental contact is possible. The 110 mm depth fits standard NSX enclosures; backplate mounting with horizontal or vertical orientation gives flexibility in tight cabinets.