The Siemens SENTRON 5SY4502-8 is a D-curve miniature circuit breaker rated at 2 A AC, 1P+N (switched neutral), occupying 2 modular width units (36 mm) on a DIN rail. It carries a 10 kA breaking capacity per IEC 60898-1 and 35 kA per IEC 60947-2 / UL1077, making it suitable for high-fault-current industrial panels where the D-curve delays tripping on inrush — typical for motor-starting or transformer-fed loads.
D-curve and derating — what matters for panel fit
The D-curve characteristic (tripping between 10× and 20× In) is designed to ride through the high inrush of motor-starting or transformer primary energisation without nuisance trips. At 2 A rated, that means the magnetic trip holds up to roughly 20–40 A peak. The thermal derating is published: 2 A at 35 °C, 1.9 A at 40 °C, 1.85 A at 45 °C, 1.8 A at 50 °C, 1.75 A at 55 °C, and 1.7 A at 60 °C — so in a warm enclosure, size up accordingly if continuous load approaches the 2 A line.
Snap-on 36 mm width (2 MW) fits standard DIN-rail enclosures. IP20 with connected conductors.