The Schneider Electric A9N21385 is a Prodis DT40N miniature circuit breaker — 3-pole, 10 A rated current, C-curve magnetic trip (5 to 10 x In). It clips onto a DIN rail, occupies 6 x 9 mm pitches (54 mm wide), and stands 81 mm tall with a 78 mm depth. This is a distribution-grade MCB for AC networks at 50 Hz.
Breaking capacity and dual standard
Rated at 6000 A 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 means it's certified for both residential (60898-1) and industrial (60947-2) applications — useful when the same panel feeds mixed loads and the SCCR study calls for the higher Icu figure.
Panel integration
Clip-on mounting to DIN rail, tunnel-type terminals accept 0.75...16 mm² rigid or 0.33...10 mm² flexible upstream and downstream. Tightening torque 2 N·m, strip length 13 mm. IP20 finger-safe front. Pollution degree 3 per IEC 60947-2 — suitable for the typical control panel environment where conductive dust is present.