The Siemens SENTRON 5SY4140-8 is a 1-pole miniature circuit breaker with a D tripping characteristic, rated 400 V AC (60 V DC) and carrying a 10 kA breaking capacity per EN 60898-1 and 15 kA per IEC 60947-2. The D-curve means it tolerates high inrush currents — typically motor starts, transformer energization, or capacitive loads — without nuisance tripping, making it a fit for industrial and mechanical-engineering panels where inductive loads dominate. At 18 mm wide (1 MWU), it snaps onto a DIN rail via the quick-assembly system and mounts in any position, which simplifies dense panel layouts. The IP20 rating with connected conductors means it is protected against finger contact but not washdown — standard for enclosed distribution boards.
Breaking capacity and standards coverage
The 5SY4140-8 is dual-rated: 10 kA under EN 60898-1 (the residential/commercial standard) and 15 kA under IEC 60947-2 (the industrial standard). It also carries a 15 kA DC rating per IEC 60947-2 at 60 V DC, and a 5 kA rating per UL 1077 / CSA C22.2 No.235 for North American supplementary protection. This triple-jurisdiction coverage (IEC/EN, UL, CSA) simplifies BOM harmonization across plants in different regions. Pollution degree 3 and overvoltage category III mean it is rated for the harsh electrical environment inside an industrial panel — not just clean, climate-controlled switchgear.
Panel integration notes
Depth of 76 mm (installation depth 70 mm) and width of 18 mm. The combined terminal top and bottom accept supply from either side. Sealable — a lockable cover can be fitted to prevent unauthorized operation. Halogen-free and silicon-free construction matters for environments with strict outgassing limits (clean rooms, medical, food processing).