What the ratings mean for fit
The Siemens SENTRON 5SY4202-8CC is a 2-pole miniature circuit breaker rated 2 A with a D tripping characteristic. That D curve means it's built for loads with high inrush currents — think motor starters, small transformers, or solenoid banks where the initial surge would nuisance-trip a B or C curve. The 10 kA breaking capacity at 400 V AC (per EN 60898) tells you it can safely interrupt a fault current up to that level without welding contacts or cascading upstream. That's the standard for most industrial panel feeder circuits. At 2 A it's a protection device for a lightly loaded circuit — a control transformer primary, a small PLC power supply feed, or a signal-conditioning loop. The 2-pole configuration switches both phase and neutral (or both phases on a split-phase system), giving full isolation. It snaps onto a standard DIN rail and takes up 2 modular width units (36 mm), which is tight enough to leave room in a crowded panel.
Where it fits in the panel
The 5SY4202-8CC mounts in any position on a standard DIN rail via the quick assembly system. Depth is 76 mm (70 mm installation depth behind the panel face), so it clears most shallow enclosures. The IP20 rating with connected conductors is typical for inside a closed panel — no washdown rating, so keep it behind the gland plate. Both top and bottom terminals accept combined (screw and clamp) conductors. The housing is halogen-free and silicon-free, which matters if this panel sits in a clean room or near sensitive electronics that could corrode from off-gassing.