The Siemens SIRIUS 3RA2120-1CA23-0AP6 is a non-fused motor starter, a direct starter design combining a contactor and thermal overload relay in a single Size S0 package. It is rated for 750 W at 400 V and carries a Trip Class 10 thermal bimetallic overload release, meaning it trips within 10 seconds at 7.2× the set current — fast enough to protect standard induction motors during a locked-rotor event without nuisance tripping during normal start. This unit ships with the 3RT2023-1AP60 contactor and the 3RA2921-1AA00 link module pre-assembled. The circuit-breaker side is sized S00, matching the S0 feeder frame. Snap it onto a DIN rail or screw-mount it with the additional push-in lug — the vertical mounting position is specified. The coil accepts 176 to 242 V at 50 Hz or 192 to 264 V at 60 Hz. Main terminals accept stranded wire from 1 to 10 mm², or two conductors of 2.5 to 6 mm² each.
No backwards clearance is needed. The depth of 97.1 mm and height of 193.1 mm determine enclosure depth and door cutout.