What the ratings mean for your panel
The Siemens 5SY4306-8CC is a SENTRON miniature circuit breaker — 3-pole, D tripping characteristic, rated 6 A at AC. The D curve means it tolerates high inrush currents (typically 10–20× rated), so it's the right choice for motor starters, transformers, or power supplies that pull a heavy surge on energization. The 10 kA breaking capacity per EN 60898 tells you it can safely interrupt a fault current up to that level without welding contacts or cascading upstream — essential for coordination in a distribution board. Under UL 1077 the same part carries a 5 kA interrupting rating, so verify which standard governs your installation.
Mounting and integration
Snaps onto DIN rail via the quick-assembly system; occupies 3 modular width units (54 mm). Depth is 76 mm, installation depth 70 mm — fits standard distribution enclosures without crowding the gland plate. Mounting position is any; IP20 with connected conductors means it's for dry indoor panels only, not washdown areas. Terminal top and bottom are combined (busbar-friendly), and the design is halogen-free and silicon-free — relevant for clean-room or corrosive-environment specs.
Thermal derating and environment
Rated 6 A at 35 °C ambient; at 40 °C it derates to 5.51 A, at 50 °C to 4.97 A, and at 55 °C to 4.69 A. If your panel runs hot (say 50 °C inside), size the load to stay under 5 A per pole. Operating range is -40 °C to 75 °C, with humidity limits: max 95% up to 55 °C, then derating to 35% at 75 °C. Overvoltage category III and pollution degree 3 — suitable for fixed installations downstream of the main distribution board.