Motor protection circuit breaker, 0.8 A, Class 10 — SIRIUS 3RV1021-0HA10-ZX95
The Siemens SIRIUS 3RV1021-0HA10-ZX95 is a 3-pole motor protection circuit breaker rated for 0.8 A continuous current, with a Class 10 trip characteristic and a 100 kA breaking capacity at 400 V AC. It is designed for motor protection in industrial control panels, with screw-type terminals for the main and auxiliary circuits. The unit mounts via screw and snap-on onto 35 mm DIN rail per DIN EN 50022, and the front face carries IP20 protection.
What the ratings mean for fit
The 0.8 A continuous current rating sets the motor FLA it protects — sized for a small motor drawing roughly 0.8 A at full load, corresponding to 0.18 kW at 400 V AC-3 duty. The Class 10 trip curve means it clears overloads within 10 seconds at 7.2× rated current, fast enough to protect standard induction motors during stall or jam conditions without nuisance tripping on normal starting inrush. The 100 kA breaking capacity at 400 V AC means it can safely interrupt fault currents up to that level without upstream fuses or breakers needing to clear first — useful for high-fault panels where SCCR headroom matters. Phase failure detection is built in, so the breaker trips if one phase drops out — preventing single-phasing damage to the motor. Ground fault detection is not included, so a separate ground-fault relay or GFCI breaker is needed if that protection is required.
Panel integration and mounting
The 45 mm width and 97 mm height fit a standard 35 mm DIN rail footprint, with 0 mm clearance needed at the sides or rear — it can be placed flush against adjacent devices. Depth is 96 mm from the rail to the front of the housing, which fits most standard enclosures with 120 mm or deeper back-panel clearance. Screw terminals accept 2x (1 to 2.5 mm²) solid or stranded, and 2x (2.5 to 6 mm²) for larger conductors, with AWG equivalents of 2x (14 to 10). The IP20 front means it is protected against finger contact but not washdown — suitable for dry indoor panel environments only.
Compliance and documentation
The product carries RoHS compliance with a substance prohibition date of 01.05.2012, and REACH compliance is standard for Siemens SIRIUS components. The IP20 front protection and 6 kV surge voltage resistance are specified per IEC/EN 60947-2 and 60947-4-1 standards for motor protection circuit breakers. Operating temperature range is -20 to +60 °C, with storage and transport range of -50 to +80 °C. Shock resistance is rated at 25g for 11 ms.