The Siemens 3RV2032-4UA15 is a SIRIUS motor protection circuit breaker — a screw-and-snap-on unit for 35 mm DIN rail (DIN EN 60715) that combines a Class 10 thermal-magnetic trip with a 50 kA interrupting capacity at 400 V. That 50 kA figure at 400 V means it can safely clear a bolted fault on a large industrial distribution board without needing an upstream current-limiting fuse; the 4 kA rating at 690 V still covers most European 690 V motor circuits.
At 55 mm wide, 149 mm deep, and 140 mm tall, this breaker takes a single 55 mm slot on the DIN rail — no different from a standard 3-pole contactor footprint. The screw-and-snap-on fastening (DIN EN 60715) lets you clip it onto the rail first, then torque the M6 main contacts. Any mounting position works, so you can lay it sideways in a shallow gland plate if needed.
The auxiliary contact ratings cover 24 V at 1 A, 60 V at 0.15 A, and 230 V at 0.5 A; no contact at 110/125/220 V, so do not plan a 110 V control loop off this breaker without checking the auxiliary load curve. Conductor cross-section: 2x (0.5 to 1.5 mm²) or 2x (0.75 to 2.5 mm²) solid or stranded.