What it is and what it does
The Siemens SIRIUS 3RV2011-1DA20-ZW97 is a motor protection circuit breaker — a single device that combines a circuit breaker and overload relay for a motor branch. It's designed for motor protection, with phase failure detection built in, and trips on overload at CLASS 10 (so it clears within 10 seconds at 7.2× the thermal setting, which is the standard for standard-start induction motors on conveyors, pumps, and compressors). Rated for 20 to 690 V, it delivers a 100 kA short-circuit breaking capacity at 400 V — meaning it can safely interrupt a fault current up to that level without cascading upstream. At 690 V the SCCR drops to 10 kA, still enough for most 690 V motor circuits in heavy industrial panels.
Mounting and panel fit
Snaps onto 35 mm DIN rail per DIN EN 60715, or screws directly to a backplate. At 45 mm wide, it takes one standard 45 mm slot on the rail — same footprint as a SIRIUS contactor of the same frame, so you can gang them without extra spacing. Depth is 97 mm, which clears most 120 mm deep enclosures. Clearance requirements: 50 mm above and below, 30 mm to the side, zero forwards or backwards. That means you can pack it tight against a backpanel or another device front-to-back, but need breathing room top and bottom for the arc chute and wiring.
Terminals and wiring
Main circuit uses spring-loaded terminals — no screwdriver torque to check, no loosening from vibration. Accepts 2× (0.5 to 4 mm²) solid or stranded per clamp. That's fine for motor leads up to about 4 mm² (roughly 12 AWG) and daisy-chaining a second conductor for a control transformer or auxiliary circuit.