The Schneider Electric A9F44370 is an Acti9 iC60N miniature circuit breaker — a 3-pole, 0.5 A rated, C-curve device built to protect branch circuits in commercial and industrial panels. The 0.5 A rating is the continuous current it carries without tripping; the C-curve means its magnetic trip activates at 5 to 10 times rated current (8 x In ±20% here), so it handles moderate inrush from small transformers or control loads without nuisance tripping.
DIN-rail fit and wiring details
The 54 mm width (6 x 9 mm pitches) occupies three standard modular slots on the rail. Depth is 78.5 mm, height 85 mm — check gland-plate clearance if the panel is shallow. Terminals accept 1 to 25 mm² rigid or 1 to 16 mm² flexible; strip length is 14 mm. The thermal-magnetic trip unit gives 10,000 electrical cycles and 20,000 mechanical cycles — fine for a distribution board that sees infrequent switching. The trip indicator and contact position indicator give visual confirmation of state without needing a multimeter.
Dual-certified to EN/IEC 60947-2 (industrial) and EN/IEC 60898-1 (household / similar) — that covers both the high breaking capacity (60947-2) and the standard MCB coordination (60898-1). Earth-leakage protection is handled by a separate block (not built-in).