Siemens 5SY6405-8 — 4-pole D-curve MCB, 0.5 A, for industrial branch circuits
The Siemens 5SY6405-8 is a SENTRON 5SY6 series miniature circuit breaker with 4 poles (4P), a D tripping characteristic, and a 0.5 A rated current at 400 V AC. The D-curve means it tolerates inrush currents 10–20× rated — typical for motor starters, transformers, or lighting ballasts — without nuisance tripping on startup. At DC, it handles 72 V max with a 15 kA breaking capacity per IEC 60947-2, and under UL 1077 / CSA C22.2 No. 235 it is rated 5 kA at AC.
Mounting and wiring — quick-assembly DIN rail, 4 width units
Sealable, halogen-free, silicon-free. IP20 with connected conductors; touch protection built in.
Overvoltage category III. Humidity influence: max 95% at 55 °C, derating to 55% at 70 °C, 35% at 75 °C. Functional designation per DIN EN 61346-2 and DIN EN 81346-2: letter F. Suitability for mechanical engineering and industrial environments.