SIRIUS 3RA2 direct starter — panel fit and motor protection
The 3RA2120-1BD23-0AP6 is a non-fused direct starter from the Siemens SIRIUS 3RA2 family, combining a contactor and a thermal bimetallic overload relay in one S0-size package. The supplied contactor is the 3RT2023-1AP60, and the link module 3RA2921-1AA00 ties the contactor and overload together. The busbar adapter 8US1251-5NT10 is included for snapping onto 60 mm busbar systems. Rated operational voltage is 690 V maximum, with control supply accepted at 176...242 V at 50 Hz and 192...264 V at 60 Hz. The unit draws 1.63 A at 480 V and 1.72 A at 600 V.
Mounting dimensions and clearance envelope
The starter measures 45 mm wide, 155 mm deep, and 260 mm tall. It mounts vertically and requires 30 mm clearance upwards, 10 mm forwards, 10 mm downwards, and 9 mm at the side for airflow and wiring access. No backwards clearance is needed. The S0 load feeder size and S00 circuit-breaker size define the panel cutout and busbar interface. Stranded main contacts accept 1...10 mm² or 2x (2.5...6 mm²) wire.
Operating environment and approvals
The starter operates in ambient temperatures from -20 to +60 °C, stores at -50 to +80 °C, and transports at -55 to +80 °C. Pollution degree 3 means it tolerates conductive dust and condensation typical in industrial panels. Assignment type 2 coordination means the starter coordinates with a backup short-circuit protective device (typically a circuit-breaker or fuse) to ensure no damage to the starter under short-circuit conditions up to the rated breaking capacity.