Siemens 5SY4140-7 SENTRON MCB — 1-pole C-curve, 10/15 kA breaking capacity
The Siemens 5SY4140-7 is a 1-pole miniature circuit breaker from the SENTRON series, designed for branch-circuit protection in industrial control panels. Its C characteristic (tripping class C) handles moderate inrush from motor starters and contactor coils without nuisance tripping — the magnetic trip fires at 5–10× rated current, so it's a standard fit for mixed resistive-inductive loads in mechanical engineering and industry applications. Breaking capacity is rated 10 kA per IEC/EN 60898-1 and 15 kA per IEC 60947-2, with a DC rating of 15 kA at 60 V (max 72 V) per IEC 60947-2. Under UL 1077 and CSA C22.2 No. 235 it carries 5 kA. That 15 kA figure at 400 V AC means it can safely interrupt a fault up to that level without welding contacts or cascading upstream — important for coordination studies on a 400 V distribution board. The 18 mm width (1 modular unit) and 76 mm depth let it drop into a standard DIN-rail enclosure alongside other SENTRON breakers. Mounting position is any; the quick-assembly system clips onto the rail without tools. IP20 with connected conductors — fine for enclosed panels, not for washdown zones.
Standards and compliance
Rated to IEC/EN 60898-1 and IEC/EN 60947-2, plus UL 1077 and CSA C22.2 No. 235. That dual standard coverage means it's accepted in both IEC (CE-mark) and North American (UL/CSA) jurisdictions — one part number for global machine builds. Halogen-free and silicon-free construction, sealable, overvoltage category III, pollution degree 3. Ambient temperature range -40 °C to 75 °C, with humidity derating above 55 °C.