The Schneider Electric A9N21568 is a 1P+N miniature circuit breaker from the Clario iDPN N range, rated 20 A with a D tripping curve. It protects final subcircuits against overloads and short-circuits in residential or light commercial distribution boards, with a 6 kA breaking capacity at 230 V AC per EN/IEC 60898-1. The D curve means the magnetic trip operates at 10 to 14 times the rated current (In), so 200 A to 280 A instantaneous — designed for loads with high inrush, like small motors, transformers, or fluorescent lighting banks. The thermal-magnetic trip unit handles the overload side. It clips onto a DIN rail (EN 60715) and occupies 2 x 9 mm pitches (18 mm wide), leaving the neutral on the left.
Pollution degree 3 per IEC 60947-1 and tropicalisation class 2 per IEC 60068-1 cover it for humid or mildly contaminated environments.
Wire stripping length is 13 mm; tighten tunnel terminals to 2 N·m. The toggle gives clear ON/OFF local indication. Earth-leakage protection requires a separate RCD block — not integrated.