The Schneider Electric A9F08440 is an Acti9 iC60H miniature circuit breaker rated at 40 A with a D tripping curve, four protected poles, and a breaking capacity of 42 kA Icu at 12–133 V AC (50/60 Hz) per EN/IEC 60947-2.
The D curve (magnetic trip at 12 x In ±20 %) means this breaker tolerates high inrush currents — typical for motor loads, transformers, or welding equipment — without nuisance tripping. The 40 A continuous rating and 4-pole configuration suit it for three-phase distribution with a switched neutral, common in European panel builds. Breaking capacity is derated by voltage: 42 kA at 12–133 V AC, 30 kA at 220–240 V, 15 kA at 380–415 V, and 10 kA at 440 V. The 10 kA Icn at 400 V per EN/IEC 60898-1 is the standard for domestic/commercial distribution; the higher Icu figures per 60947-2 cover industrial fault levels. For a 40 A feeder in a 400 V panel with a prospective fault current under 10 kA, this breaker is a clean fit. Thermal-magnetic trip technology with a separate earth-leakage block option means the A9F08440 handles overload and short-circuit protection on its own; add a Vigi iC60 module downstream if residual-current protection is needed. The isolation suitability mark (per both 60947-2 and 60898-1) confirms it can be used as a disconnecting means.
Deployment context
The 78.5 mm depth fits flush in most 100 mm deep enclosures.