SIRIUS reversing starter, S0 frame, 750 W at 400 V
The Siemens 3RA2220-1BD23-0BB4 is a SIRIUS non-fused reversing motor starter in size S0 — a single assembly that combines a reversing contactor pair, a thermal bimetallic overload relay, and the interlock wiring into one package. The 24 V DC coil means it integrates directly into 24 VDC control circuits common in PLC-based panels — no additional transformer or AC-to-DC conversion needed at the starter itself.
Mounting and panel fit — snaps onto 60 mm busbar
Fastening method is for snapping onto 60 mm busbar systems — no DIN rail required if the busbar is present, which saves rail space and speeds assembly. Mounting position is vertical. Dimensions: 165 mm depth, 90 mm width, 260 mm height. Clearance requirements: 30 mm upwards, 10 mm forwards, 10 mm downwards, 9 mm at the side, zero backwards. These add up to a compact footprint for a reversing starter — the backwards zero clearance is convenient for panel wiring access against a backplate.
Supplied subassemblies — what's in the box
The unit ships with the contactor (3RT2023-1BB40), the link module (3RA2921-1BA00), and the busbar adapter (8US1251-5NT10) already integrated. Main contact wire range: 1 to 10 mm² stranded, or 2x (2.5 to 6 mm²); AWG equivalent 2x (16 to 12) or 2x (14 to 8).