What it is and what it does
The Siemens SIRIUS 3RV1342-4AC10 is a three-pole circuit breaker designed specifically for starter combinations — meaning it integrates motor protection and disconnection in one unit, sized for a 16 A continuous current and rated to switch 7.5 kW at 400 V AC. Its breaking capacity is the headline: 100 kA at both 240 V and 400 V AC, dropping to 30 kA at 500 V and 12 kA at 690 V. That 100 kA figure at 400 V means it can safely interrupt a fault current up to that level without upstream devices needing to clear it — critical for high-fault panels where selectivity matters.
Mounting and wiring
Snaps onto a 35 mm DIN rail per EN 50022, with zero clearance needed at the sides or rear — so you can pack it tight in a panel. Mounting position is any orientation; the IP20 front face keeps fingers out during commissioning. Main circuit terminals are screw-type with box terminals. Solid conductors accept 2x 2.5 to 16 mm²; stranded goes up to 2x 10 to 50 mm² or 1x 10 to 70 mm². That range covers most motor feeder cables from 4 mm² up to 35 mm² without adapters. Auxiliary and control circuits use separate screw terminals, and the unit supports an auxiliary switch add-on (product extension auxiliary switch: Yes).
Lifecycle and compliance
RoHS compliance date is July 1, 2006, covering the EU RoHS directive. Surge voltage resistance is rated at 6,000 V, and the unit is finger-safe for touch protection.