What it is and what it does
The Siemens SIRIUS 3RV1342-4EC10 is a three-pole circuit breaker designed for starter combinations — meaning it combines motor protection (overload and short-circuit) in one compact device that coordinates directly with a contactor. It carries a continuous current rating of 32 A and a rated voltage of 690 V, so it handles standard 400 V motor circuits with headroom. The 100 kA breaking capacity at 400 V AC means it can safely interrupt a fault current up to that level without upstream fuses needing to clear first — a key spec for high-fault panels where selectivity matters.
Mounting and integration
Mounts via screw and snap-on onto 35 mm standard mounting rail per DIN EN 50022 — the standard DIN rail found in every industrial panel. No side clearance needed (0 mm at the side, 0 mm backwards), so you can pack breakers tight on the rail. The IP20 front protection means it's finger-safe for the panel face but not washdown-rated; keep it inside a closed enclosure. Any mounting position is allowed, which simplifies layout in crowded cabinets.
Termination and wiring
Main current circuit uses screw-type box terminals. Solid conductors: 2x (2.5 to 16 mm²). Stranded: 2x (10 to 50 mm²) or 1x (10 to 70 mm²). Finely stranded with ferrule: 2x (2.5 to 35 mm²) or 2.5 to 50 mm². That range covers most motor feeder cables up to 70 mm² on a single run. Auxiliary and control circuit terminals are also screw-type, separate from the main power path.