What it is and what it does
The Siemens 3RV2031-4EA10-ZW97 is a SIRIUS motor protection circuit breaker designed for motor protection, with a Class 10 trip characteristic that clears overloads before the motor winding exceeds its thermal limit during start-up — critical for standard induction motors on pump, fan, and conveyor loads. It carries a 30 kA breaking capacity at 400 V, meaning it can safely interrupt a bolted fault up to that level without upstream fuses or a larger breaker needing to clear first — a key spec for panel builders sizing the short-circuit withstand of the feeder. Phase failure detection is built in, so a lost phase on the supply side trips the breaker rather than letting the motor single-phase and overheat — a feature that saves the motor, not just the circuit.
Mounting and integration
Mounts via screw or snap-on onto 35 mm DIN rail per DIN EN 60715, in any orientation — no forced airflow or upright-only restriction, which simplifies layout in crowded control panels. Dimensions are 149 mm deep, 55 mm wide, and 140 mm tall — the 55 mm width is a standard 3-module footprint on the DIN rail, so it occupies three 18 mm slots and leaves room alongside for contactors or auxiliary blocks. Clearance requirements: 50 mm above and below, 10 mm to the side, and zero forward or backward clearance needed — so it can sit flush against a back panel or enclosure wall.