Reversing starter in a Size S0 frame
The Siemens 3RA2220-1KF24-0BB4 is a SIRIUS reversing starter — a pre-assembled combination of a reversing contactor pair, a thermal bimetallic overload relay, and a link module in a single Size S0 package. The control coil is rated 24 VDC.
Mounting and wiring — DIN rail, spring terminals
Mounts on a 35 mm standard DIN rail via the supplied adapter for screw or snap-on fastening. The mounting position is vertical. Dimensions: 90 mm wide, 269 mm tall, 130 mm deep. Clearance requirements: 50 mm upward, 32 mm forward, 10 mm at the sides and downward, zero backward. Main current circuit wiring uses spring-loaded terminals — no screw torque to verify, just strip and push. The supplied contactor is a 3RT2024-2BB40, the link module is 3RA2921-2AA00, and the reversing assembly kit is 3RA2923-1BB2.
Environmental range and compliance
Operates from -20 to +60 °C; storage and transport range is -50 to +80 °C. The overload relay includes temperature compensation across the operating range. RoHS compliance date is 03/01/2017.