Integrator's quick take
The Siemens 3RV1021-4DA15 is a SIRIUS motor protection circuit breaker rated for 25 A continuous current, with a Class 10 trip characteristic — meaning it opens within 10 seconds at 7.2× rated current, matching the thermal curve of standard induction motors during locked-rotor starts. It delivers 11 kW at 400 V AC-3 duty, so it directly covers a 15 hp (11 kW) motor on a 400 V line. The 50 kA SCCR at 400 V is the key number for panel builders: that interrupting capacity means this breaker can clear a bolted fault up to 50 kA without upstream fuses — a real advantage in high-fault installations.
Mounting and panel fit
Mounts via screw and snap-on onto 35 mm DIN rail per EN 50022, in any orientation. The 45 mm width and 96 mm depth fit standard enclosures.
Compliance and documentation
RoHS compliant per substance prohibition date of 05/01/2012. The SIRIUS series carries UL, CSA, and CE approvals for global panel acceptance. Phase failure detection is built in — the breaker trips on loss of one phase, preventing single-phasing damage. No ground fault detection on this variant.