The Schneider Electric A9KF71403BQ is a 3 A, 4-pole miniature circuit-breaker from the Acti9 K60H series, built to EN/IEC 60898-1. Rated 3 A continuous and breaking 10,000 A Icn at 415 V AC 50/60 Hz, this breaker clears faults up to that level without welding its contacts or blowing apart — that's the interrupting rating that matters for coordination downstream of a distribution panel. It's also certified as suitable for isolation per EN/IEC 60898-1, meaning you can use it as a visible-break disconnect for the downstream circuit during maintenance, provided you lock it off.
Height is 81 mm, depth 70 mm. Terminals accept 1 to 25 mm² rigid or 1 to 16 mm² flexible copper; strip 14 mm and torque to 2 N·m. The tunnel-type terminals on both upstream and downstream sides make daisy-chaining busbars straightforward. IP20 finger-safe front, pollution degree 2, tropicalisation class 2 per IEC 60068-1 — handles 95% RH at 55 °C, so it'll survive a humid panel room or coastal plant environment.
The C-curve means the magnetic trip fires between 5 and 10 times In. 10 kA Icn at 415 V AC is the short-circuit breaking capacity per EN/IEC 60898-1. Limitation class 3 means it limits let-through energy well. Rated for 20,000 mechanical and 20,000 electrical cycles — that's the endurance life. In a panel that sees a few operations a day, that's decades of service before the mechanism wears out.