The Schneider Electric A9K23306 is an Acti9 iK60N miniature circuit breaker (MCB) — 3-pole, 6 A rated current, curve B, with a 6 kA breaking capacity at 400 V AC.
The 6 A rating at 30 °C sets the continuous current it carries without tripping — sized for a lighting or small resistive load branch, not a motor or high-inrush circuit. For a panel fed from a transformer with a typical 10 kA prospective fault current, this MCB needs upstream current-limiting protection (a higher-rated MCCB or fuse) to keep the let-through energy within its rating. Three protected poles in a 3P form factor mean it switches all three phases simultaneously — correct for a three-phase distribution subcircuit, not a single-phase branch. The 440 V insulation rating confirms it's rated for 400 V three-phase networks.