What this SIRIUS breaker is and what it does
The Siemens 3RV1021-4CA15-ZX95 is a SIRIUS motor-protective circuit breaker rated for 22 A continuous current and 11 kW at 400 V AC-3 duty, with a CLASS 10 trip characteristic that clears overloads fast enough to protect standard induction motors during start-up. It carries a 100 kA breaking capacity at 240 V AC, dropping to 50 kA at 400 V and 10 kA at 500 V — figures that tell you it handles high-fault-current panels without needing an upstream current-limiting fuse in most installations. Phase failure detection is built in, so a lost leg on the supply side trips the breaker rather than letting the motor single-phase and burn.
Mounting and panel integration
Snaps onto a 35 mm DIN rail per EN 50022 — screw and snap-on fastening, no tools for the rail mount itself. At 45 mm wide, 97 mm tall, and 96 mm deep, it fits a standard single-module footprint in a motor control centre or distribution panel. Mounting position is any orientation, and the IP20 front face keeps fingers off live parts inside the enclosure.
Termination and wiring
Main and auxiliary circuits use screw-type terminals. The main circuit accepts 2x (0.5…1.5 mm²) solid or 2x (0.75…2.5 mm²) stranded, plus 2x (2.5…6 mm²) stranded on the larger side — covers standard motor cable sizes up to 6 mm². Auxiliary switch terminals are transverse design, taking 2x (14…10) AWG for the control wiring.