The Siemens 3RV1011-0JA20-ZW95 is a SIRIUS motor protection circuit breaker designed to guard a 0.25 kW motor at 400 V AC — that's a 1 A continuous current rating with a CLASS 10 trip curve, meaning it will clear a stalled-rotor condition fast enough to keep the motor windings from cooking before the overload relay can catch it. It snaps onto a 35 mm DIN rail (DIN EN 50022) and screws down for vibration resistance — out here in the grease, that screw-down keeps it from rattling loose on a conveyor line.
Breaking capacity and protection
Rated breaking capacity hits 100 kA at 240 V, 400 V, 500 V, and 690 V AC — that's a full-range short-circuit rating that covers most industrial supply voltages without derating. Phase failure detection is built in, so a lost leg on a three-phase motor won't go unnoticed — the breaker trips before single-phasing cooks the winding. Power dissipation runs 5.5 W total hot, 1.8 W per pole — panel builders need to account for that in a sealed enclosure to avoid derating the breaker itself.
Mounting and wiring
Mounts in any position; 45 mm wide, 90 mm tall, 81 mm deep — fits a standard 45 mm module slot on the rail. Main circuit uses spring-loaded terminals accepting 2x (0.25 to 2.5 mm²) solid or 2x (0.25 to 1.5 mm²) finely stranded with ferrule — no screw torque to check, just strip and push. IP20 on the front; keep it inside a cabinet — this is not a washdown-rated device.