What this MCB is and where it lands in a panel
The Siemens 5SY4613-8 is a 4-pole (3P+N) SENTRON miniature circuit breaker with a D tripping characteristic, rated 13 A at 35 °C and 50/60 Hz. It snaps onto a DIN rail via the quick-assembly system, occupies 4 modular width units (72 mm), and accepts wiring from either top or bottom through the combined terminals. The D curve means it tolerates inrush currents up to 10–20× rated — sized for motor and transformer branch circuits where the start-up surge would nuisance-trip a B or C curve breaker.
Breaking capacity and selectivity headroom
Rated breaking capacity is 10 kA per EN 60898 and 20 kA per IEC 60947-2. The higher IEC figure gives you selectivity headroom downstream of a distribution board with a 25 kA or 36 kA upstream breaker — the 5SY4613-8 will clear a fault without the main breaker tripping, provided the let-through energy is coordinated. Pollution degree 3 and overvoltage category III confirm it for industrial fixed-installation panels, not just residential.
Thermal derating and environmental range
Rated 13 A at 35 °C, the 5SY4613-8 derates to 12.38 A at 40 °C, 12.05 A at 45 °C, 11.73 A at 50 °C, 11.38 A at 55 °C, and 11.02 A at 60 °C. If your panel ambient sits at 50 °C, size the branch load to 11.73 A continuous, not the nameplate 13 A. The breaker itself survives -40 °C to 75 °C ambient and mounts in any orientation — useful for outdoor cabinets or unheated enclosures. Halogen-free and silicon-free construction matters if the panel is in a clean room or near sensitive optics.