The Schneider Electric A9N21415 is a DT40N miniature circuit breaker from the ProDis range, rated 10 A with a D-curve magnetic trip of 10...14 x In. That trip band is sized for loads with high inrush — think motor starters, small transformers, or capacitor banks — where a B- or C-curve would nuisance-trip on startup. The 3P+N configuration (three protected poles plus a switched neutral) suits three-phase distribution panels where the neutral needs to be disconnected with the phases. Breaking capacity is dual-rated: 6 kA Icn at 400 V AC per EN/IEC 60898-1 for general distribution, and 10 kA Icu at 400...415 V AC per IEC 60947-2 for industrial circuits with higher fault current. IP20 finger-safe terminals — standard for panel-mount, not for wet environments.
It carries dual certification to EN/IEC 60898-1 and IEC 60947-2, plus NF quality label and tropicalisation class 2 per IEC 60068-1 (95 % RH at 55 °C). That dual standard is useful: the 60898-1 rating covers domestic/commercial distribution, while the 60947-2 rating satisfies industrial panel requirements — one part, two compliance boxes.
Integration and deployment
The 54 mm width (6 modules) occupies six 9 mm pitches in the enclosure — plan your rail fill accordingly. Neutral is on the left, which matches typical European panel layout conventions. Earth-leakage protection requires a separate block (not integrated). If you need RCD functionality, you'll add a downstream or companion residual-current device. The thermal-magnetic trip unit handles overload and short-circuit only.