The 5SY7108-8CC is a Siemens SENTRON miniature circuit breaker — a 1-pole (1P) unit with a D tripping characteristic, rated 8 A at 400 V AC. The 25 kA breaking capacity per IEC 60947-2 tells you this breaker can safely interrupt a fault current up to 25,000 A at 400 V AC without welding its contacts or venting arc gas into the panel — that's a high-interrupting rating for a single-module (18 mm wide) MCB, sized for industrial main or sub-distribution boards where the prospective short-circuit current is substantial. Under UL 1077 and CSA C22.2 No. 235, the same breaker is rated 5 kA, which is the relevant figure for North American supplementary protection applications. The terminal range accepts solid or stranded copper from 0.75 mm² up to 35 mm², with a tightening torque of 2.5 to 3.5 N·m. That 35 mm² top end is unusually large for a single-pole 8 A breaker — it means the terminals are physically sized to accept a feeder conductor that is much heavier than the load current requires, which is useful when the breaker is used as a tap protector or when the same panel design uses a common busbar size across multiple breaker ratings. The combined terminal design (top and bottom) accepts both busbar pins and screw-clamp conductors, so it drops into a SENTRON distribution board without extra adapters. The breaker is sealable, halogen-free, silicon-free, and rated IP20 with conductors connected.
Compliance documentation is standard for a Siemens SENTRON product: the breaker carries IEC 60947-2 certification (the 25 kA rating), UL 1077 and CSA C22.2 No. 235 recognition (5 kA), and is designed to meet RoHS and REACH requirements. The product designation per DIN EN 61346-2 and DIN EN 81346-2 is 'F' (protective device).
Deployment context
The ambient temperature range is -25 to +55 °C, with humidity derating up to 95% at 55 °C, 55% at 70 °C, and 35% at 75 °C. Storage range is wider: -40 to +75 °C. The touch protection feature (finger-safe terminals when conductors are connected) is standard for the 5SY7 series.