The Siemens 5SJ4140-7HG41 is a SENTRON 1-pole miniature circuit breaker with C-curve trip characteristic, rated 10 kA per EN 60898 and 15 kA per IEC 60947-2. It handles 400 V AC and 60 V DC, with a 1-module-width (18 mm) footprint that snaps onto standard DIN rail. The C-curve means it trips between 5 and 10 times rated current — standard for general-purpose branch circuits and moderate inrush loads like small motors or lighting.
What the ratings mean for fit
The 10 kA breaking capacity under EN 60898 covers most residential and light commercial panelboards; the 15 kA under IEC 60947-2 gives headroom for industrial distribution where fault currents run higher. The 400 V AC rating suits single-phase line-to-neutral circuits in 230/400 V systems; the 60 V DC rating opens up control-circuit and battery-backed applications, though DC breaking is limited to single-pole and must respect polarity. The 1-module width (18 mm) is the standard MCB slot — it fits any 18 mm-wide DIN-rail position without adapters. Temperature range from -40 °C to 75 °C means it can live in unheated enclosures or near hot equipment; the 95% humidity tolerance handles condensation-prone environments. Pollution degree 3 and overvoltage category 3 are typical for fixed installations inside a panel. The IP20 rating (with conductors connected) is standard for a DIN-rail device; the handle area is IP40, so accidental tool contact won't trip it.