The A9P42725 is a 25 A B-curve miniature circuit breaker from Schneider Electric's Acti9 iC40 range, wired as 3P+N — three protected poles plus a switched neutral on the left. Thermal-magnetic trip technology handles both overload (thermal bimetal) and short-circuit (solenoid) in one package. Breaking capacity is 4.5 kA Icn per EN/IEC 60898-1 at 400 V AC, and 6 kA Icu per EN/IEC 60947-2 at the same voltage. That dual rating means it qualifies for both household-style distribution panels (60898-1) and industrial switchgear (60947-2). The 6 kA Icu figure is the ultimate breaking capacity — the breaker can safely interrupt one fault at that level and still be functional afterward; the 4.5 kA Icn is the service rating for repeated operation. For most commercial distribution boards fed by a 100 kVA or smaller transformer, 6 kA is adequate. If your fault current exceeds that, you need upstream current-limiting or a higher-rated device. Clip-on mounting to DIN rail (EN 60715) and tunnel terminals accepting 1–16 mm² rigid or 1–10 mm² flexible wire. Tightening torque 2 N·m. The 54 mm width (6 x 9 mm pitches) is standard for a 3P+N module — plan your rail fill accordingly. IP20 finger-safe on the front, IP40 inside the modular enclosure.
Dual-certified to EN/IEC 60898-1 (household-type MCB) and EN/IEC 60947-2 (industrial circuit-breaker). Limitation class 3 per 60898-1 means it limits let-through energy well — useful for downstream equipment protection. IMQ quality mark. Suitability for isolation confirmed per 60947-2, with a visible contact position indicator (ON/OFF plus trip flag).