What it is and what it does
The Siemens 5SY4410-7CC is a SENTRON miniature circuit breaker (MCB) with a 4-pole (4P) design, rated 10 A at 440 V AC with a C tripping characteristic. It provides overcurrent and short-circuit protection in final subcircuits, with a 10 kA breaking capacity per EN 60898 — sufficient for most commercial and light industrial distribution boards where the prospective fault current stays under that threshold.
Key ratings and what they mean for fit
The C-curve trips between 5× and 10× In (50–100 A for this 10 A unit), which suits moderate inrush loads like small motors, transformers, and fluorescent lighting banks. The 10 kA breaking capacity at 230/400 V AC (per EN 60898) means it can safely interrupt a fault up to that level without welding contacts or cascading failure upstream — match this to your supply-side SCCR during panel coordination. Thermal derating is published: at 40 °C ambient the continuous rating drops to 9.4 A, at 50 °C to 8.76 A, and at 55 °C to 8.42 A. If this breaker sits in a warm enclosure or next to other heat sources, size the load accordingly — don't run 10 A through it at 50 °C and expect no nuisance tripping. The 4-pole design switches all four phases (L1, L2, L3, N) but the neutral conductor is not switched separately — it's a switched-neutral configuration where the neutral pole opens and closes with the phases. Verify your distribution scheme: if you need a solid neutral (unswitched), this isn't the right variant.
Mounting and integration
Snaps onto DIN rail via the quick-assembly fastening method, occupying 4 modular width units (72 mm wide). Mounting position is any orientation, and the installation depth behind the panel is 70 mm — account for that when laying out gland plates and backplane clearance. The IP20 rating (with connected conductors) means it's protected against finger contact but not moisture; keep it inside a sealed enclosure in washdown or outdoor environments. Combined terminals top and bottom accept copper conductors; the design is halogen-free and silicon-free, which matters for environments sensitive to outgassing (clean rooms, medical, or certain industrial processes).