The Siemens SENTRON 5SL4401-8 is a 4-pole miniature circuit breaker with a D tripping characteristic, rated 1 A at 400 V AC. It breaks fault currents up to 10 kA per both EN 60898 and IEC 60947-2, which means it handles high inrush loads like motor starting or transformer energization without nuisance tripping — the D curve holds through the surge and only clears on sustained overloads or shorts.
The D-curve trips magnetically between 10x and 20x In (10–20 A for this 1 A unit), so it's sized for loads with a high starting surge — think small motors, solenoid banks, or control transformers in a panel. At 40 °C ambient the continuous rating derates to 0.96 A; at 55 °C it's 0.9 A (–). The 4 MW width (72 mm,) snaps into a standard DIN rail; the 70 mm installation depth leaves room behind the gland plate for wiring.
Deployment context
The 5SL4401-8 is rated for residential buildings and infrastructure, but the D curve and 4-pole format put it in commercial and light industrial distribution boards too — anything needing a dedicated 3-phase + neutral branch with inrush tolerance. The -40 to +75 °C storage range covers unheated warehouses or roof-mounted enclosures.