The Schneider Electric A9F58250 is a 2-pole thermal-magnetic miniature circuit breaker from the Acti9 IKQ series, rated 50 A with a D tripping curve (magnetic trip threshold 10–14 x In). It breaks 10,000 A Icn at 415 V AC 50/60 Hz per EN 60898-1, making it a fit for motor-starting or high-inrush loads where a standard C curve would nuisance-trip.
The D curve's 10–14 x In magnetic trip (500–700 A instantaneous) is sized for transformer inrush, motor starting, or welding equipment — loads that pull a short-duration surge well above running current. Rated insulation voltage is 440 V AC, operational voltage 415 V AC — both at 50/60 Hz. IP20 finger-safe terminals are standard for enclosed gear; no earth-leakage protection built in.