The Schneider Electric A9F05125 is an Acti9 iC60N miniature circuit breaker — a 1-pole, 25 A, D-curve unit built for distribution boards. The D curve (magnetic trip at 12 x In ±20%) means it handles high inrush loads like motor starters and transformers without nuisance tripping, while the 25 A rated current (In) sets the continuous load ceiling. Breaking capacity is where this part earns its keep: 36 kA Icu at 12-60 VAC and 20 kA at 100-133 VAC per EN/IEC 60947-2, with a 6 kA Icn rating at 230 VAC per EN/IEC 60898-1. That SCCR headroom gives selectivity downstream — a 36 kA fault at the panelboard won't cascade upstream if the fault current stays under that limit. The thermal-magnetic trip unit covers both overload (thermal bimetal) and short-circuit (solenoid) protection in one 18 mm wide package. Mounts on a DIN rail (EN 60715), occupies 2 x 9 mm pitches (18 mm total width), and accepts double terminals top and bottom — rigid up to 25 mm², flexible up to 16 mm². Strip length is 14 mm, torque to 2 Nm.
Integration notes
The 18 mm width and 91 mm height fit standard DIN-rail enclosures; depth of 78.5 mm leaves clearance for gland plates and wiring ducts. The toggle control and trip indicator give local status at a glance. Overvoltage category IV means it's rated for the main distribution board, not just sub-panels.