The C25B32D250 is a Schneider Electric ComPacT NSX250B moulded-case circuit breaker (MCCB) in the ComPacT range, rated 250 A at 40 °C with a MicroLogic 2.2 electronic trip unit. The MicroLogic 2.2 provides L (long-time overload), So (short-time short-circuit with fixed delay), and I (instantaneous short-circuit) protection curves, so you can coordinate selectively downstream without nuisance tripping on motor inrush or transformer energisation. Breaking capacity is 40 kA Icu at 220/240 V AC, 25 kA at 380/415 V, 20 kA at 440 V, and 15 kA at 500 V, all per IEC 60947-2. The 3-pole (3P) version covers three-phase distribution.
Selectivity and coordination
This allows cascaded selectivity with downstream breakers — a 250 A feeder can hold in for a downstream 100 A branch fault long enough for the branch breaker to clear, keeping the rest of the panel live. Utilisation category A means it is not intended for frequent switching of motor loads under normal operation — it is a distribution breaker, not a motor starter. For motor circuit protection, pair it with a contactor and overload relay upstream.
Connection pitch is 35 mm, so busbar or cable lugs align with standard 35 mm centres. IP40 enclosure protection is fine for clean indoor panels; IK07 impact resistance handles accidental tool drops during maintenance. Mounts horizontally or vertically flat on the backplate — no derating needed for orientation.