SIRIUS reversing starter — S0 frame, 20 A AC-3
The 3RA2220-4BF27-0AP0: It ships as a factory-assembled unit including the 3RT2027-2AP00 contactor and the 3RA2921-2AA00 link module — no field assembly of reversing interlock hardware required. The reversing starter is designed for standard DIN-rail mounting on 35 mm rail via an adapter, or screw-mounting to a backplate. The vertical mounting position is specified; forced ventilation clearance of 50 mm upward and 32 mm forward is needed per the installation guidelines.
AC-3 duty and trip class — what they mean for motor control
Main circuit connections use spring-loaded terminals — no screw torque verification needed, and vibration resistance is inherent. The S0 frame size keeps the envelope at 90 mm wide × 269 mm tall × 130 mm deep, fitting standard motor starter slots in control panels. Operating temperature range is -20 to +60 °C; storage and transport range is -50 to +80 °C. The unit is not PROFIsafe or PROFINET IO capable — it is a standalone reversing starter for hardwired forward/reverse control circuits.
Current production — sourcing and availability
The same genuine Siemens part, different passport — the unit carries full manufacturer traceability regardless of which authorized region supplied it.