What it is and where it fits
The Siemens 3RV2311-0HC20 is a SIRIUS circuit breaker designed specifically for starter combinations — meaning it's the protection device that sits ahead of a contactor in a motor branch circuit, not a general-purpose feeder breaker. It's built into the Size S00 frame, which is the smallest in the SIRIUS lineup, and it's rated for 100 kA breaking capacity at 400 V AC, so it can interrupt fault currents up to that level without the upstream device needing to trip.
Mounting and panel fit
Mounts via screw or snap-on onto 35 mm standard mounting rail per DIN EN 60715. The 45 mm width and 97 mm depth mean it takes up one standard 45 mm module slot on the rail — no extra clearance needed sideways. Clearances: 50 mm above and below, 30 mm to the side, zero forward or backward. Mounting position is any orientation, which helps in tight enclosures.
Breaking capacity and coordination
The 100 kA breaking capacity holds across the full voltage range: 240 V, 400 V, 500 V, and 690 V AC. That's a Type 2 coordination rating — it means downstream contactors and overloads survive a short-circuit event without damage, assuming the right combination. The main contacts are rated for 100,000 mechanical operations typical, so it's built for production-line cycling, not just backup protection.
Termination and wiring
Main current circuit uses spring-loaded terminals — no screw tightening, just push the ferrule in. Accepts 2x 0.5 to 4 mm² solid or stranded. The screwdriver shaft for the auxiliary terminal needs a 3 mm diameter tip, 3.0 x 0.5 mm size. No ground-fault or phase-failure detection built in — that's handled by the upstream or downstream protection.