What this SIRIUS 3RA2 starter packs
The 3RA2120-0KD23-0BB4 is a Siemens SIRIUS non-fused motor starter — a direct-starter assembly that combines a contactor, a thermal bimetallic overload relay (CLASS 10 trip class), and a magnetic short-circuit trip in one unit that snaps onto a 60 mm busbar system. It ships with the 3RT2023-1BB40 contactor, the 3RA2921-1BA00 link module, the 8US1251-5NT10 busbar adapter, and the 3RV2011-0KA10 circuit-breaker — everything needed for a coordinated motor feeder in one order code.
Ratings that decide the fit
Control voltage is 24 V, so the coil draws from a 24 VDC or 24 VAC supply — common in PLC-driven panels where the I/O bus runs at 24 V. The load feeder is size S0, and the integrated circuit-breaker is size S00 — this combination fits the standard SIRIUS modular system, meaning the same busbar adapter and link module pattern used across the S0 frame.
Mounting and panel integration
Snaps directly onto a 60 mm busbar system — no DIN rail required for the main power connection, though the control wiring still needs terminal access. Mounting position is vertical only. Dimensions: 45 mm wide, 165 mm deep, 260 mm tall. The 45 mm width is a single modular unit on the busbar, so a 600 mm bar holds 13 starters with room for end caps and wiring ducts. Clearance requirements: 30 mm upwards, 10 mm forwards, 10 mm downwards, 9 mm at the side, and 0 mm backwards — the back sits flush against the mounting surface.
Environmental and compliance
Degree of pollution 3 means the starter is rated for conductive pollution environments typical of industrial control panels — no additional conformal coating needed for normal factory air. Substance prohibitance date of 03/01/2017 confirms RoHS compliance — the starter contains no restricted substances above threshold levels as of that date.
Sourcing reality — current production, quoted to order
No official successor or cross-reference exists for this order code — it is the active variant.