Siemens 5SY8550-7 — SENTRON MCB, C-Curve, 1P+N, 25 kA
It is rated for 25 kA breaking capacity at 230 V AC per IEC 60947-2, and 15 kA at 60 V DC per the same standard. For UL 1077 recognition, the interrupting rating is 5 kA.
Breaking capacity and selectivity — what the ratings mean
For a panel designer, that figure governs the upstream fuse or breaker coordination — you need a device with equal or higher breaking capacity ahead of it to maintain selectivity. The 15 kA DC rating at 60 V applies to battery-backed or DC bus circuits, common in industrial control panels.
Mounting, environment, and accessories
Snap-on mounting to DIN rail, any position. Operating temperature range spans -40 °C to 75 °C, with humidity derating above 55 °C (max 95% RH at 55 °C, dropping to 35% at 75 °C). Vibration resistance per IEC 60068-2-6: ±1 mm at 5–25 Hz, 50 m/s² at 25–150 Hz.