The Schneider Electric A9P64620 is an Acti9 iC40N miniature circuit breaker — a 20 A, D-curve, 1P+N unit that clips onto a DIN rail inside a distribution board. The D curve (magnetic trip 10–14 × In per EN/IEC 60898-1, or 12 × In ±20% per EN/IEC 60947-2) is the key selection parameter: it tolerates the high inrush of motor, transformer, or welding loads without nuisance tripping, while still clearing a hard short. The 10 kA Icu at 230 V AC (EN/IEC 60947-2) tells you it can safely interrupt a fault current up to that level; the lower 6 kA Icn (EN/IEC 60898-1) is the rated short-circuit capacity for residential-type duty. For a panel builder, the 18 mm width per pole means this 1P+N unit occupies 2 modules (36 mm) of DIN rail — standard for a single-phase final subcircuit with switched neutral.
The 74 mm depth fits flush in most distribution boards; the 85 mm height and 18 mm width per pole are the standard Acti9 footprint. Terminals accept 1–16 mm² rigid or 1–10 mm² flexible copper, with a tightening torque of 2 N·m. The IP20 finger-safe front (IP40 in modular enclosure) is standard for indoor panel use. Dual-certified to EN/IEC 60898-1 (domestic) and EN/IEC 60947-2 (industrial), with pollution degree 3 and suitability for isolation. Quality labels include AENOR and OVE.