The Schneider Electric A9N3P50DIN is an Acti9 xC60 miniature circuit-breaker rated 50 A with a D curve, three protected poles, and a breaking capacity of 6 kA Icn at 380–415 V AC (IS/IEC 60947-2) and 15 kA Icu at 100–125 V DC. The D curve means the magnetic trip activates at 12 x In (±20 %), so 50 A × 12 = 600 A instantaneous. That high threshold is deliberate: it avoids nuisance trips on motor-start inrush, transformer magnetising current, or capacitive loads that pull a heavy surge for a few cycles. The thermal-magnetic trip unit handles the long-time overload side — bimetal heats up on sustained overcurrent — while the magnetic coil handles short-circuit. Category A (no intentional short-time delay) per IS/IEC 60947-2 means it clears fast; coordination with downstream devices depends on the let-through energy, not a deliberate delay.
Height 85 mm, depth 77.5 mm — fits standard distribution enclosures. Biconnect bottom terminals let you daisy-chain the outgoing side without an extra terminal block. IP20 finger-safe front, pollution degree 3, overvoltage category IV — rated for the main distribution board, not just sub-panels.