The Schneider Electric A9N21400 is a DT40N miniature circuit breaker from the ProDis range, rated 40 A with a D tripping curve (magnetic trip between 10 and 14 times In). It handles 3 protected poles, so it's a straight three-phase distribution breaker. Breaking capacity is 6 kA Icn at 400 V AC per EN/IEC 60898-1, and 10 kA Icu at 400–415 V AC per IEC 60947-2. That dual rating matters: the 60898-1 number is the service breaking capacity for general distribution, while the 60947-2 Icu is the ultimate short-circuit capacity — useful if this breaker sits in an industrial panel where fault levels are higher than a residential board. The part is certified to both standards, so it can be specified in either a commercial or light industrial context.
Standards and approvals you can cite
Dual-certified to EN/IEC 60898-1 and EN/IEC 60947-2, which means it meets both the residential/commercial MCB standard and the industrial switchgear standard. Also carries NF quality marking.