The C125N32EFM is a 3-pole fixed-mount ComPacT NS new generation MCCB from Schneider Electric, rated 1250 A at 50 °C with a MicroLogic 2.0 E electronic trip unit. It carries an N breaking capacity code — 50 kA Icu at 380/415 V AC per IEC 60947-2 — which means it can safely interrupt a bolted fault up to that level on a 415 V distribution bus without upstream cascading.
The MicroLogic 2.0 E provides L (long-time overload) and I (instantaneous short-circuit) protection curves, with an electronic trip unit that holds thermal memory for 20 minutes after a trip event. That thermal memory matters for motor or transformer feeders where repeated inrush can heat the conductor without reaching the instantaneous threshold — the trip unit remembers the prior thermal state and shortens the allowable cool-down. The energy meter measurement type means the unit reports energy consumption data through the LCD display, useful for submetering a distribution panel without a separate meter.
Rated Icu at 440 V AC is 50 kA, dropping to 40 kA at 500/525 V AC and 30 kA at 660/690 V AC. The utilisation category B rating means the breaker is tested for selectivity under short-circuit conditions — it can be used as the main or tie breaker in a selective scheme where downstream devices clear faster and this unit stays closed to keep healthy feeders live.
Physical integration and environment
Fixed backplate mount, 210 mm wide by 327 mm tall by 147 mm deep, with a 70 mm connection pitch. IP40 enclosure protection keeps out tools and debris but is not rated for washdown — this is a dry indoor gear installation. IK07 impact rating means it withstands a 2 J hammer blow, typical for a switchboard environment.
Operating altitude is 0 to 2000 m without derating, with derating required above 2000 m up to 5000 m.