It is part of the SIRIUS family, a modular system for motor feeders and control circuits. Rated for Class 10 trip characteristics, it clears overloads quickly enough to protect standard motors during start-up, while the integrated phase failure detection ensures the motor drops out if one supply phase is lost — a common cause of single-phasing damage. Breaking capacity is 100 kA at 400 V AC and 500 V AC, dropping to 10 kA at 690 V AC.
The 45 mm width (3 module spaces) fits standard enclosure rail layouts, and the 97 mm depth leaves clearance for wiring behind the panel door. Screw-type terminals on the main circuit accept 2x (1 to 2.5 mm²) solid/stranded or 2x (2.5 to 10 mm²) — sized for motor feeder cables up to 10 mm². Mounting position is any orientation, so it works in tight side-entry panels.
No official successor has been announced, so the 3RV2021-1DA10 remains the direct fit for any existing SIRIUS motor feeder design. If you are stocking a spare for a legacy panel, this is the one to put in the cabinet.