The Siemens 5SY6105-8CC is a 1-pole miniature circuit breaker from the SENTRON 5SY6 series, rated 0.5 A with a D tripping characteristic. Breaking capacity is 6 kA per EN 60898 and 5 kA per UL 1077 / CSA C22.2 No.235, so it clears faults up to that level without cascading upstream. The 400 V AC rated voltage covers standard three-phase line-to-neutral applications; DC rating maxes at 72 V. Terminal accepts solid or stranded conductors from 0.75 to 35 mm²; tightening torque 2.5–3.5 N·m. Mounting position any, ambient temperature -25 to +55 °C, storage -40 to +75 °C. IP20 with conductors connected. Sealable cover and touch protection built in.
The 5SY4140-7 is a 1-pole B-curve 40 A MCB — same SENTRON family, same 18 mm width and DIN-rail mount. The D-curve and 0.5 A rating on the 5SY6105-8CC make it a different animal: it's for low-current inductive loads (small contactor coils, relay banks, signal transformers) where the B-curve would trip on inrush. They share the terminal range (0.75–35 mm²) and IP20 rating, but the 5SY6105-8CC won't drop into a 40 A feeder slot without rewiring the branch. If you're replacing a 5SY4140-7 with this, check the load current first — 0.5 A won't carry a 40 A circuit.
Approvals and compliance documentation
Rated per EN 60898 (6 kA) and UL 1077 / CSA C22.2 No.235 (5 kA). Overvoltage category III. The part is halogen-free and silicon-free. Standard compliance documentation (CE, UKCA, RoHS, REACH) is available from Siemens; the datasheet covers the full declaration. No marine or ATEX approvals listed on this variant.