What this reversing starter delivers in a reversing duty panel
The 3RA2220-1GF24-0BB4 is a SIRIUS reversing starter — a factory-assembled pair of contactors with mechanical and electrical interlocking, sized S0, that handles motor reversing without external interlocks or added panel wiring. The supplied contactor is a 3RT2024-2BB40, and the link module is 3RA2921-2AA00 — the assembly arrives as a single order code, saving the BOM line items and the panel-builder's interlock wiring time.
Mounts on a 35 mm DIN rail via the included adapter, or screws directly to a backplate — the vertical mounting position is specified, so horizontal orientation would affect the overload relay's ambient compensation. The envelope is 90 mm wide by 269 mm tall by 130 mm deep, with 50 mm clearance required above and 10 mm below for airflow and wiring access — the S0 feeder size matches the standard S0 circuit-breaker footprint upstream.
The 24 V DC coil suits modern PLC-driven panels where 24 V control is standard — the coil draw is consistent with the SIRIUS contactor range, so the power supply sizing follows the same rules as the 3RT2 series.