What the ratings mean for fit
The A9F77325 is a 25 A rated, 3-pole miniature circuit breaker from the Acti9 iC60N range. The C-curve (magnetic trip at 8 x In ±20%) means it handles moderate inrush from motor starters, small transformers, and lighting banks without nuisance tripping — a typical choice for general distribution circuits in commercial and light industrial panels. Breaking capacity is the headline number that decides whether this breaker holds in a high-fault location. At 36 kA Icu (12–133 V AC) it clears severe faults near the service entrance; at 20 kA (220–240 V) it covers most panelboard mains; at 10 kA (380–415 V) it suits sub-distribution boards. The 6 kA rating at 440 V AC is the tail-end — verify the available fault current at the installation point before committing the BOM line. Dual-rated to EN/IEC 60947-2 (industrial) and EN/IEC 60898-1 (household / commercial), so it qualifies for either duty class. Pollution degree 3 and overvoltage category IV mean it's rated for the harsh electrical environment of a main distribution board — not just a clean sub-panel.
Panel integration and mounting
Snaps onto a standard DIN rail (mounting support per). The 54 mm width × 85 mm height × 78.5 mm depth footprint occupies 6 x 9 mm pitches — count the rail space before laying out a multi-pole group. Terminals accept 1–25 mm² rigid or 1–16 mm² flexible; strip length 14 mm, torque to 2 N·m. IP20 finger-safe terminals suit enclosed panels; no washdown rating here.