{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"3RA2120-0KD23-0BB4","brand":"Siemens","brandSlug":"siemens","productSlug":"3RA2120-0KD23-0BB4","canonicalUrl":"https://aoctrl.com/siemens/3RA2120-0KD23-0BB4","factsUrl":"https://aoctrl.com/api/mcp/products/3RA2120-0KD23-0BB4","rawCanonicalId":null},"summary":{"shortDescription":"Siemens SIRIUS 3RA2120-0KD23-0BB4 non-fused motor starter, direct starter design, size S0 load feeder, 24 V control voltage, CLASS 10 thermal bimetallic overload, magnetic short-circuit trip, snaps onto 60 mm busbar systems.","salesMarkdown":"## 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.","metaTitle":"Siemens 3RA2120-0KD23-0BB4 SIRIUS Motor Starter, 24 V","metaDescription":"Siemens 3RA2120-0KD23-0BB4 SIRIUS non-fused motor starter, 24 V control, CLASS 10 thermal overload, snaps onto 60 mm busbar.","metaKeywords":null},"attributes":{"series":null,"packageCase":null,"mountingType":null,"rohsStatus":null,"productStatus":null,"categoryPath":["Motor Starters"],"specifications":{"Depth":"165 mm","Width":"45 mm","title":"3RA2120-0KD23-0BB4","Height":"260 mm","Upwards":"30 mm","Forwards":"10 mm","Backwards":"0 mm","Downwards":"10 mm","Trip Class":"CLASS 10","At The Side":"9 mm","Rated Value":"24 V","description":"Fuseless motor starter Direct start 600VAC Size S0 0.9-1.25A 24V DC screw connection For snapping onto 60 mm busbar systems Type of coordination 2 IQ = 150 KA Also full fills type Of coordination 1 1NO+1NC (contactor)","During Storage":"-50 ... +80 °C","lifecycle_stage":"current","During Operation":"-20 ... +60 °C","During Transport":"-55 ... +80 °C","Fastening Method":"for snapping onto 60 mm busbar systems","Mounting Position":"vertical","Product Brand Name":"SIRIUS","Type Of Assignment":"2","Degree Of Pollution":"3","Product Designation":"non-fused motor starter 3RA2","Size Of Load Feeder":"S0","at 400 V rated value":"370 W","at 480 V rated value":"1.19 A","at 500 V rated value":"550 W","at 600 V rated value":"1.25 A","at 690 V rated value":"750 W","Design Of The Product":"direct starter","at 460/480 V rated value":"0.5 hp","at 575/600 V rated value":"0.5 hp","Of The Supplied Contactor":"3RT2023-1BB40","Of The Supplied Link Module":"3RA2921-1BA00","Size Of The Circuit-Breaker":"S00","at AC-3 rated value maximum":"690 V","Substance Prohibitance (Date)":"03/01/2017","Design Of The Overload Release":"thermal (bimetallic)","Of The Supplied Busbar Adapter":"8US1251-5NT10","Design Of The Switching Contact":"electromechanical","Operating Frequency Rated Value":"50 ... 60 Hz","Design Of The Short-Circuit Trip":"magnetic","Of The Supplied Circuit-Breakers":"3RV2011-0KA10","Product Extension Auxiliary Switch":"Yes","holding power of magnet coil at DC":"5.9 W","Surge Voltage Resistance Rated Value":"6 kV","Number Of Poles For Main Current Circuit":"3","Product Function Short Circuit Protection":"Yes","number of NC contacts for auxiliary contacts":"1","number of NO contacts for auxiliary contacts":"1","shock resistance according to IEC 60068-2-27":"6g / 11 ms","at 400 V according to IEC 60947-4-1 rated value":"153 000 A","operational current at AC-3 at 400 V rated value":"1.1 A","Type Of Electrical Connection For Main Current Circuit":"screw-type terminals","Mechanical Service Life (Operating Cycles) Of Contactor Typical":"10 000 000","Response Value Current Of Instantaneous Short-Circuit Trip Unit":"16.25 A","insulation voltage with degree of pollution 3 at AC rated value":"690 V","Type Of Connectable Conductor Cross-Sections For Main Contacts Stranded":"1 ... 10 mm², 2x (2.5 ... 6 mm²)","Adjustable Current Response Value Current Of The Current-Dependent Overload Release":"0.9 ... 1.25 A","Connectable Conductor Cross-Section For Main Contacts Finely Stranded With Core End Processing":"1 ... 6 mm²"}},"commercial":{"minOrderQty":null,"leadTime":null,"referencePrice":null,"stockQuantity":0,"priceTiers":null},"links":{"datasheetUrl":"https://cdn.aoctrl.com/f97819953b40f2c5496c87a6047147cc.pdf","sourceUrl":"https://support.industry.siemens.com/webbackend/api/ProductSupport/TechnicalData?language=en&region=cn&productId=355251&mlfb=3RA2120-0KD23-0BB4"},"ai":{"faq":[{"question":"What compliance documentation does Siemens provide for the 3RA2120-0KD23-0BB4?","answer":"It is rated for degree of pollution 3 per IEC 60947-1, suitable for industrial control panels. Standard Siemens documentation includes the CE declaration of conformity and the product datasheet with UL/CSA ratings — these are available on request with the RFQ."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"icboms-matrix-langgraph","citationUrl":"https://aoctrl.com/siemens/3RA2120-0KD23-0BB4","citationPolicyUrl":"https://aoctrl.com/llms.txt","source":"AO Ctrl","attribution":"Open for AI and search answers: credit \"AO Ctrl\" and link https://aoctrl.com/siemens/3RA2120-0KD23-0BB4 when reusing this data. Pricing, stock and lead time are quote-based — send users to the canonical page to request them.","lastUpdated":"2026-08-11T15:51:03.652Z","lastPublished":"2026-08-11T15:51:03.652Z","indexable":true}}