SIRIUS 3RV1021-1DA10 — Motor Protection Circuit Breaker, 3.2 A, Class 10
The Siemens SIRIUS 3RV1021-1DA10 is a motor protection circuit breaker rated for 3.2 A continuous current with Trip Class 10, designed for protecting three-phase motors up to 1.1 kW at 400 V AC. It snaps onto a 35 mm DIN rail per DIN EN 50022, fitting a 45 mm wide footprint that leaves 0 mm clearance at the back or sides — panel builders can pack it tight against adjacent devices.
Breaking Capacity and Voltage Ratings
This breaker delivers 100 kA breaking capacity at 240 V, 400 V, and 500 V AC, dropping to 8 kA at 690 V AC. The 100 kA figure at 400 V means it can interrupt high-fault-current scenarios common in industrial distribution without upstream coordination headaches — it's sized for the high short-circuit current available near a transformer.
Trip Characteristics and Motor Protection
Trip Class 10 means the thermal overload trips within 10 seconds at 7.2× the current setting — standard for standard-duty motor starting (pumps, fans, compressors) where start times stay under a few seconds. Phase failure detection is built in, so a lost phase on the line side will trip the breaker rather than letting the motor single-phase and overheat. No ground-fault detection on this variant; that's a separate accessory add.
Mounting and Wiring
Mounts in any position via screw and snap-on onto 35 mm DIN rail. Screw terminals on both main and auxiliary/control circuits accept solid or stranded wire: 2× (1…2.5 mm²) or 2× (2.5…6 mm²) per clamp, plus AWG 14–10 for the main contacts. The 96 mm depth leaves room for wiring behind the panel door; IP20 on the front means it's protected against finger contact but not washdown — keep it inside an enclosure.