The A9F45402 is a 4-pole Acti9 iC60N miniature circuit breaker rated 2 A with a D curve, meaning the magnetic trip operates at 12 x In (24 A) plus or minus 20%. The thermal-magnetic trip unit handles the overload side; the magnetic element clears short-circuits. Dual-rated to EN/IEC 60898-1 and EN/IEC 60947-2, so it qualifies for both domestic-distribution and industrial panel applications.
Depth 78.5 mm, height 85 mm. The 4-pole form factor with a single neutral and three protected poles means it fits a 4-wire three-phase distribution board. Terminals accept 1–25 mm² rigid or 1–16 mm² flexible, stripped to 14 mm, torqued to 2 N·m. IP20 finger-safe front; padlockable for lockout-tagout. The white housing with a toggle actuator and trip indicator is standard Acti9 family appearance.
D curve selection logic
The D curve (12 x In magnetic trip) distinguishes this from the more common B (3–5 x In) or C (5–10 x In) variants in the same iC60N family. For a 2 A rating, the D curve holds through a 24 A peak before the magnetic element fires — that is the deciding factor for transformer primary protection or contactor coil circuits where the inrush lasts several cycles. If the load is resistive or general-purpose with no high inrush, a C curve would trip faster on fault; but for motorized or inductive loads, D is the correct call.