The Siemens SIRIUS 3RV1021-1DA15 is a motor-protective circuit breaker rated for 3.2 A continuous current, designed for 1.1 kW motor loads at 400 V AC. Its CLASS 10 trip characteristic means it disconnects within 10 seconds at 600% of the set current, matching the thermal curve of standard induction motors during locked-rotor starts — so it protects the motor without nuisance tripping on normal starting inrush. The 100 kA breaking capacity at 400 V AC means it can safely interrupt a short-circuit fault up to that level without needing an upstream fuse, simplifying panel coordination.
Mounting and panel integration
Mounts via screw and snap-on onto 35 mm DIN rail per DIN EN 50022. The 45 mm width and 97 mm height with 96 mm depth fit standard motor starter combos alongside a contactor on the same rail. Zero clearance required at the sides and rear — no derating for adjacent units in a dense panel. Screw-type terminals on both main and auxiliary circuits accept solid conductors up to 2x 2.5 mm² or stranded up to 2x 6 mm², which covers the wire sizes for a 3.2 A motor branch.
Protection features and ratings
Phase failure detection is built in — the breaker trips if one phase drops out, preventing single-phasing damage to the motor. No ground-fault detection, so that must be handled externally if needed. The auxiliary switch is a transverse design and the product extension allows adding an auxiliary switch block for remote status or PLC feedback. Shock resistance rated at 25g for 11 ms suits it for mobile or vibrating equipment. Operating frequency is limited to 15 operations per hour at AC-3 duty — fine for occasional start/stop, not for high-cycle jogging.
Power dissipation at rated current in hot operating state is 7.25 W — account for this heat in panel thermal calculations when grouping multiple breakers. The 3.2 A continuous rating with CLASS 10 trip makes this a direct fit for protecting a 1.1 kW motor at 400 V or smaller motors at lower voltages. For 24 V control circuits, the auxiliary contacts are rated 1 A; at 230 V they carry 0.5 A.