The Schneider Electric A9K24603 is a 1P+N miniature circuit-breaker from the Acti9 iK60N series, rated 3 A at 30 °C with a C-curve trip characteristic (magnetic tripping between 5 and 10 times In). It breaks 6000 A Icn at 230 V AC, 50/60 Hz, per EN/IEC 60898-1, which covers the standard domestic and light commercial fault-clearing requirement.
In a 40 °C panel, expect the effective rating to drop; the thermal element responds to ambient heat. For installations where the available fault current exceeds 6 kA, you need a higher-rated upstream breaker or a current-limiting device. The C-curve (5–10 x In) means instantaneous trip occurs between 15 A and 30 A — suitable for circuits with moderate inrush, not for transformer or motor-start loads that would need a D-curve.
The 1P+N form factor takes 4 module pitches at 9 mm each, so 36 mm of rail width. Neutral is on the left, which matters when laying out busbar or comb-bridge runs in a distribution board. Tunnel terminals accept 1 to 25 mm² rigid or 1 to 16 mm² flexible copper; strip 14 mm and torque to 2 N.m. IP20 finger-safe front, but the terminals are live when the breaker is on — standard for a distribution board interior.