What this SIRIUS 3RV1021-0HA15 is and what it does
The Siemens 3RV1021-0HA15 is a SIRIUS motor protection circuit breaker designed for motor protection, with a continuous current rated value of 0.8 A and Trip Class 10. It provides phase failure detection and offers a breaking capacity of 100 kA at 400 V AC, meaning it can safely interrupt high fault currents on motor circuits without upstream damage. The unit mounts via screw and snap-on onto 35 mm standard mounting rail per DIN EN 50022, fitting into any standard control panel enclosure. Main circuit connections use screw-type terminals accepting solid conductors 2x (0.5 to 1.5 mm²) and 2x (0.75 to 2.5 mm²), or stranded 2x (1 to 2.5 mm²) and 2x (2.5 to 6 mm²).
Key ratings and what they mean for your motor circuit
The 0.8 A continuous current rating sets the thermal pickup for motor overload protection — this breaker is sized for small motors drawing under an amp at full load. Trip Class 10 means the breaker will trip within 10 seconds at 7.2× the rated current, protecting motors with short starting times like pumps and small conveyors. Breaking capacity of 100 kA at 400 V AC (also 100 kA at 240 V, 500 V, and 690 V AC) covers virtually any installation fault level without needing upstream fuses. The auxiliary switch (transverse design) provides a signal contact rated 1 A at 24 V, 0.5 A at 230 V, and 0.15 A at 60 V — enough for PLC or relay feedback. Power dissipation at AC in hot operating state is 7.25 W — factor this into enclosure thermal calculations when grouping multiple breakers.
Mounting and integration into the panel
Width 45 mm, height 97 mm, depth 96 mm — fits a standard 45 mm-wide DIN-rail slot with zero clearance needed at the sides or back. Mounting position is any orientation, giving flexibility in tight enclosures. Front protection rating IP20 covers the operator interface; the unit is intended for installation inside a closed panel, not for washdown environments. Operating temperature range -20 to +60 °C; storage and transport -50 to +80 °C. Shock resistance rated at 25 g for 11 ms — suitable for mounting on machinery subject to vibration.