The A9N19853 is a 2-pole miniature circuit breaker from the Acti9 C120L series, rated 100 A at 30 °C with a D trip curve (magnetic trip 10–14 × In). That dual-standard rating means it qualifies for residential-distribution boards (60898-1) and industrial panel feeders (60947-2) — one part covers both specification regimes.
The D curve's 10–14× In magnetic threshold means it tolerates the starting surge of motor loads without nuisance tripping — a C curve (5–10× In) would trip on the same inrush. Terminals accept 1–50 mm² rigid or 1.5–35 mm² flexible, torqued to 3.5 N·m. The 2-pole form factor occupies 6 × 9 mm pitch modules (54 mm) on the DIN rail. Mechanical endurance is 20,000 cycles; electrical endurance is 5,000 cycles — sufficient for distribution duty where the breaker operates infrequently.