What it is and what it does
The Siemens SIRIUS 3RV1011-1JA10-0FJ0-ZX95 is a motor protection circuit breaker designed to protect induction motors against overload, short-circuit, and phase failure. Its CLASS 10 trip characteristic means it will trip within 10 seconds at 7.2× the set current — fast enough to protect standard IEC motors during a locked-rotor event without nuisance tripping on normal starts. The 10 A continuous current rating covers motors up to 4 kW at 400 V AC. Phase failure detection is built in, so a lost phase on the line side will cause the breaker to open, preventing single-phasing damage.
Breaking capacity and fault clearing
This breaker clears 100 kA at 240 V AC, 50 kA at 400 V AC, 3 kA at 500 V AC, and 2 kA at 690 V AC. At 400 V — the most common industrial distribution voltage — the 50 kA rating means it can interrupt a bolted fault on a high-capacity transformer secondary without upstream fuses needing to clear. The surge voltage resistance rating of 6 000 V ensures the internal gap withstands switching transients on inductive motor circuits.
Mounting and integration
Mounts via screw or snap-on onto 35 mm DIN rail per EN 50022. The 45 mm width and 90 mm height fit standard motor starter assemblies in a control panel. Mounting position is any orientation, which simplifies layout in tight enclosures. The IP20 front protection means it is safe for finger contact in a closed panel but not for washdown environments. Terminal capacity accepts 2× (0.5 to 1.5 mm²) solid or stranded, or 2× (0.75 to 2.5 mm²) — sized for the motor leads this breaker typically protects.