What this part is and where it fits
The Siemens 3RV2311-1DC20 is a SIRIUS circuit breaker designed specifically for starter combinations — meaning it integrates directly into a motor starter assembly, combining short-circuit and overload protection in one device that coordinates with a contactor. Rated 3.2 A at both 480 V and 600 V, it covers small motor loads up to 2 hp at 460/480 V or 575/600 V, and 0.75 hp at 220/230 V — the horsepower ratings align with standard NEMA motor frames. The breaking capacity is the headline number here: 100 kA at 240 V, 400 V, and 500 V, dropping to 10 kA at 690 V. That 100 kA SCCR at 400 V means it can safely interrupt a fault current up to 100,000 A without upstream devices needing to clear — critical for high-fault panels where you want to avoid cascading failures.
Mounting and integration
Mounts via screw or snap-on onto 35 mm standard mounting rail per DIN EN 60715, in any position. The 45 mm width (3 module spaces) and 97 mm depth fit standard panel layouts; clearance requirements are 50 mm upwards and downwards, 30 mm to the side, zero forwards or backwards. Spring-loaded terminals on the main current circuit accept 2x 0.5 to 4 mm² solid or stranded conductors — no screw torque to verify, which speeds panel wiring.
What the ratings mean for your panel
The 100 kA SCCR at 400 V is the key coordination figure — it tells the panel builder that this breaker can handle the available fault current without needing a current-limiting upstream device. For most industrial panels fed from a 400 V transformer, that's enough headroom to avoid series-rating complications. The switching frequency is capped at 15 operations per hour under AC-3 duty (motor starting). That is typical for a motor-protective device — not meant for frequent jogging or rapid cycling, but fine for normal start/stop cycles on a conveyor or pump. No ground-fault or phase-failure detection built in — this is a straight thermal-magnetic breaker for overload and short-circuit protection. If those functions are needed, they must be added externally or via a separate monitoring relay.