The Siemens 3RV1021-0EA10-ZW98 is a SIRIUS motor protection circuit breaker designed for 3-pole main current circuits, rated at 0.4 A continuous current with a Class 10 trip characteristic. It provides phase failure detection and delivers 100 kA breaking capacity across 240 V, 400 V, 500 V, and 690 V AC — meaning it can safely interrupt a bolted fault up to that level without cascading upstream, even on a 400 V line. That 100 kA figure is the same at all four voltage points, so the SCCR is flat across the operating range, not derated at higher voltage. Rated power at 400 V is 0.09 kW, which sizes it for small motor loads — fractional-horsepower pumps, fans, or conveyor drives. The 5.5 W power loss in hot operating state (1.8 W per pole) is low enough that panel ventilation requirements are minimal; you can pack it tight in a control cabinet without thermal worry.
Screw-type terminals on both main and auxiliary circuits accept solid or stranded conductors: 2x (1... 2.5 mm²) and 2x (2.5... 6 mm²), or AWG 14 to 10 for the main contacts. Finely stranded with core-end processing (ferruled) uses the same ranges. This gives flexibility for panel wiring with either solid or flexible cable.
Shock resistance is 25g for 11 ms, which is typical for industrial panel-mounted gear — it will hold calibration through shipping vibration and plant floor impacts. Front protection class is IP20, meaning finger-safe but not washdown-rated; keep it inside a cabinet.