What this MCB does on the panel
The Schneider Electric A9N1P03DGN is a 1-pole Acti9 xC60 miniature circuit-breaker rated 3 A with a D tripping curve. Breaking capacity is 10,000 A Icn at 240 V AC, 50/60 Hz, certified to IS/IEC 60898-1.
D curve — why it matters for your load
The D curve is the distinguishing spec on this 3 A MCB. Where a B curve trips magnetically at 3–5× In and a C curve at 5–10× In, the D curve holds until 10–14× In. That means a 3 A D-curve breaker will pass a 30–42 A inrush pulse without opening — exactly what you need when the load is a small motor starting direct-on-line, a solenoid bank pulling in, or a power supply charging its bulk capacitors. If the branch feeds resistive or general-purpose loads, a C curve would be the standard choice; the D curve here is deliberately selected for inductive or high-inrush circuits.
The toggle actuator gives local ON/OFF indication. IP20 finger-safe protection means it's suitable for enclosed panels only — no exposed live parts when installed in a proper enclosure.