The Schneider Electric A9K23150 is a 1-pole miniature circuit breaker from the Acti9 iK60N series, rated 50 A at 30 °C with a B-curve trip characteristic (magnetic release between 3 and 5 times In). Breaking capacity is 6000 A Icn at 230 V AC, 50/60 Hz, conforming to EN/IEC 60898-1 — sufficient for most domestic and light commercial panelboards where the prospective short-circuit current stays under that threshold.
In a warmer panel (40 °C or above), derate per the manufacturer's thermal curve — the 50 A figure is the starting point, not a hard limit across all environments. B-curve means the magnetic trip operates at 3 to 5 times rated current (150 A to 250 A for this 50 A unit). That makes it a good fit for resistive and general-purpose loads with modest inrush — lighting circuits, socket outlets, small heaters. Not ideal for motor circuits or transformers where higher inrush would nuisance-trip a B-curve; those call for a C or D curve.
Width is 18 mm (2 x 9 mm pitches), so it occupies a single module slot in a distribution board. Connection pitch between devices is 18 mm — standard for modular MCBs. IP20 finger-safe protection on the front face — suitable for enclosed panels only.