What it is and what it does
The Siemens 3RV1011-0HA25 is a SIRIUS motor-protective circuit breaker, designed to protect motor circuits against overload and short-circuit. It's rated for a continuous current of 0.8 A and a motor output of 0.18 kW at 400 V AC, with a CLASS 10 trip characteristic that matches typical motor starting curves. Breaking capacity is a solid 100 kA across the board at 240 V, 400 V, 500 V, and 690 V AC — that's a lot of fault energy it can safely interrupt without cascading upstream. It includes phase failure detection, so a lost phase won't cook the motor while it's still drawing current.
Mounting and wiring
Mounts via screw or snap-on onto 35 mm DIN rail per DIN EN 50022 — standard panel integration, no surprises. Width is 45 mm, height 90 mm, depth 81 mm, so it fits a standard 45 mm slot on the rail. Main circuit connections use spring-loaded terminals accepting 2x (0.25... 2.5 mm²) solid or stranded, or 2x (24... 14) AWG. No screw torque to worry about; just strip and push. IP20 on the front — fine for a clean panel interior, but keep it behind a door if there's washdown or dust.