Motor protection circuit breaker for the 0.25 A line
The Siemens SIRIUS 3RV1011-0CA10-0FJ0-ZX95 is a motor protection circuit breaker rated for 0.25 A continuous current, designed to protect motor circuits against overload and short-circuit. Its CLASS 10 trip characteristic means it will trip within 10 seconds at 7.2× rated current, matching the thermal curve of standard induction motors during startup. The part carries 100 kA breaking capacity at 400 V AC, so it safely interrupts fault currents up to that level without cascading upstream — critical for panel SCCR compliance. Phase failure detection is built in, which prevents single-phasing damage on three-phase motors. The breaker mounts via screw or snap-on onto 35 mm DIN rail per DIN EN 50022, and its 45 mm width fits standard panel density. Operating temperature range is -20 to +60 °C, with storage and transport from -50 to +80 °C.
Breaking capacity and coordination
Rated short-circuit breaking capacity holds at 100 kA across the voltage range: 240 V, 400 V, 500 V, and 690 V AC. That flat curve means the breaker does not derate its interrupt rating as line voltage rises — unusual for this class, and a strong signal for high-fault-capacity panels. The rated impulse withstand voltage is 6 kV, and surge voltage resistance is rated at 6 000 V, supporting coordination with upstream switchgear. Power dissipation is 5.5 W total in hot operating state, or 1.8 W per pole. For a 45 mm-wide device that is moderate; ensure adjacent devices are not tightly packed without derating if ambient runs above 40 °C.
Mounting and wiring
Mounting position is any orientation. Screw-type terminals on the main current circuit accept solid or stranded conductors: 2× (0.5 to 1.5 mm²) and 2× (0.75 to 2.5 mm²), or AWG 18 to 14. Backwards clearance is 0 mm, side clearance 0 mm, so the breaker can be ganged without spacing — useful when filling a DIN rail to the gland plate limit. Front protection is IP20; the enclosure is finger-safe but not washdown-rated.