What it is and what it does
The Siemens 3RV2011-0FA40 is a SIRIUS motor protection circuit breaker in the S00 frame size, designed to protect motors against overload and short-circuit. It snaps onto 35 mm standard mounting rail per DIN EN 60715 and can be screw-mounted as well, with any mounting position allowed. The 45 mm width and 97 mm depth mean it fits standard panel layouts without surprises — the S00 frame is the compact workhorse for smaller motor branches. Rated breaking capacity hits 100 kA at 400 V AC — that's the fault current it can safely interrupt without welding contacts or cascading upstream. Trip Class 10 means it disconnects within 10 seconds at 7.2× the thermal setting, standard for standard induction motor starts. Phase failure detection is built in, so a lost leg won't let the motor single-phase to destruction.
Mounting and integration
Mounts on 35 mm DIN rail per DIN EN 60715 with the screw-and-snap mechanism — no tools needed for the rail clip. The S00 frame leaves 50 mm clearance above and below, 30 mm to the side, and zero clearance forward or backward, so it tucks tight against the back panel. Ring cable lug connection on the main circuit; M3 screws for the main contacts. Screwdriver shaft diameter 5 to 6 mm, tip size 2 or Pozidriv 2.