The Schneider Electric A9F08240 is a 40 A, 2-pole miniature circuit breaker from the Acti9 iC60H series, with a D-curve trip characteristic. It's built for distribution panels where high inrush loads — motor circuits, transformers, discharge lighting — are the norm. The D-curve means magnetic tripping happens at 12 x In (480 A), so it rides through startup surges without nuisance trips. Rated breaking capacity hits 42 kA Icu at 12–133 V AC, 30 kA at 220–240 V, 15 kA at 380–415 V, and 10 kA at 440 V per EN/IEC 60947-2. It also carries a 10 kA Icn at 400 V per EN/IEC 60898-1 for residential or light commercial coordination.
Width is 36 mm (4 x 9 mm pitches), so it takes two adjacent slots in a typical distribution board. Double terminals top and bottom accept 1–35 mm² rigid or 1–25 mm² flexible — enough for a 40 A feed without pigtailing. IP20 finger-safe front, pollution degree 3, overvoltage category IV — rated for main-distribution duty inside a closed panel.