Panel fit and motor duty ratings
The 3RA2220-4BF27-0BB4: This SIRIUS reversing starter is a pre-assembled combination of a contactor (3RT2027-2BB40) and a link module (3RA2921-2AA00) in Size S0 footprint — 130 mm deep, 90 mm wide, 269 mm tall. The vertical mounting position and 35 mm DIN-rail adapter (screw or snap-on) are specified, with 50 mm clearance above and 32 mm forward for airflow and wiring access. Horsepower equivalents span 7.5 hp at 200/208 V up to 15 hp at 460/480 V, and 3 hp at 110/120 V.
Wiring and environmental limits
Main power circuit uses spring-loaded terminals — tool-less insertion for solid or ferruled stranded wire, which speeds panel wiring and eliminates screw-torque variability. Ambient operating range is -20 to +60 °C; storage and transport range is -50 to +80 °C. Side clearance of 10 mm on each side is required for heat dissipation.