The Schneider Electric Acti9 A9N1P03DIN is a 1-pole miniature circuit-breaker rated 3 A with a D trip curve, built to IS/IEC 60947-2. It clips onto a standard 35 mm DIN rail — 18 mm wide, 85 mm tall, 77.5 mm deep — and fits a 2-module pitch in a distribution board.
Overvoltage category IV suits it for main distribution boards, not just sub-panels.
Breaking capacity: 10 kA Icu at 240 V AC, 15 kA at 12–48 V DC, 6 kA at 60 V DC — all per IS/IEC 60947-2. That 10 kA at 240 V is adequate for most residential and light commercial service entrances in IEC markets; if your fault level is higher, step up to the 15 kA or 25 kA variants in the same Acti9 family. Thermal-magnetic trip with separate earth-leakage block option (add a Vigi module downstream). Mechanical and electrical durability both rated at 20,000 cycles — solid for a panelboard MCB.