Motor protection circuit breaker, 0.32 A, CLASS 10 — SIRIUS 3RV1021
The Siemens SIRIUS 3RV1021-0DA10-0FJ0-ZX95 is a motor protection circuit breaker rated for a continuous current of 0.32 A with a CLASS 10 trip characteristic. Rated breaking capacity hits 100 kA at 400 V AC (also 100 kA at 240 V, 500 V, and 690 V), so it can be installed upstream of a motor starter without needing a separate backup fuse in most industrial distribution panels — that 100 kA holds across the full voltage range. Phase failure detection is built in; the breaker will trip if one phase drops out, preventing single-phasing damage to the motor. No ground fault detection on this variant — that's a separate accessory.
Panel fit and wiring
Snap-on mounting onto 35 mm DIN rail per DIN EN 50022, or screw-mount via the same base. The 45 mm width is a single modular unit — one TE on the rail — and the 97×96 mm (H×D) footprint leaves room for adjacent contactors or overloads in a motor control center row. Screw-type terminals on the main circuit accept solid or stranded conductors: 2×(1…2.5 mm²) and 2×(2.5…6 mm²) per clamp. AWG equivalents are 2×(14…10). The auxiliary switch option is present, but this order code ships with zero factory-fitted auxiliary contacts — add them separately if you need status feedback. IP20 finger-safe protection on the front; the rear and sides are open to the panel environment. Mounting position is unrestricted, and zero clearance is required at the sides or rear — it can sit flush against the panel wall or adjacent devices.
What the ratings mean for your BOM line
The 0.32 A continuous rating paired with CLASS 10 trip fits small motors in the 0.09 kW range at 400 V — think fractional-horsepower pumps, fans, or conveyor drives. The 100 kA SCCR at 400 V means this breaker can be placed on a high-fault-capacity bus without series-rated fusing, simplifying panel coordination. Power dissipation is 5.5 W total at rated current in hot operating state, or 1.8 W per pole. In a dense MCC column with multiple breakers, that heat adds up — account for it in the enclosure thermal calculation. Mechanical endurance is 100,000 operating cycles typical for the main contacts.