{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"3RA2120-1HD24-0BB4","brand":"Siemens","brandSlug":"siemens","productSlug":"3RA2120-1HD24-0BB4","canonicalUrl":"https://aoctrl.com/siemens/3RA2120-1HD24-0BB4","factsUrl":"https://aoctrl.com/api/mcp/products/3RA2120-1HD24-0BB4","rawCanonicalId":null},"summary":{"shortDescription":"Siemens SIRIUS 3RA2120-1HD24-0BB4 direct (on-line) starter, Size S0, 8 A at 400 V AC-3, Class 10 trip, 45 mm wide, for 60 mm busbar systems.","salesMarkdown":"## 8 A AC-3 motor current, Class 10 — what it means for your load The 3RA2120-1HD24-0BB4: That 8 A figure is the motor-switching current — it's what drives contactor and overload sizing for a standard squirrel-cage motor under full load. For a motor that's hard to start (high inertia loads like a crusher or centrifuge), you'd want Class 20 or 30 — Class 10 is for normal-starting loads like pumps and fans. ## Snap-on mounting and panel fit This starter is designed to snap directly onto 60 mm busbar systems — no DIN rail adapter needed. The 45 mm width means it fits the standard S0 feeder footprint, and the vertical mounting position is required for proper thermal performance. Clearance distances: 50 mm upwards, 20 mm forwards, 0 mm backwards, 10 mm downwards, and 20 mm at the side. That backwards clearance of zero means you can mount it flush against the back panel — helpful when you're squeezing into a shallow enclosure. ## Supplied components — what's in the box The starter ships with a 3RT2024-1BB40 contactor and a 3RA2921-1BA00 link module already integrated.","metaTitle":"Siemens 3RA2120-1HD24-0BB4 SIRIUS Direct Starter","metaDescription":"Siemens SIRIUS 3RA2120-1HD24-0BB4 direct online starter, 8 A AC-3 at 400 V, Class 10, snaps onto 60 mm busbars. Active production, quoted to order.","metaKeywords":null},"attributes":{"series":null,"packageCase":null,"mountingType":null,"rohsStatus":null,"productStatus":"Active","categoryPath":["Motor Starters"],"specifications":{"Depth":"165 mm","Width":"45 mm","title":"3RA2120-1HD24-0BB4","Height":"260 mm","Upwards":"50 mm","Forwards":"20 mm","Backwards":"0 mm","Downwards":"10 mm","Trip Class":"CLASS 10","At The Side":"20 mm","Rated Value":"24 ... 24 V","description":"Load feeder fuseless, Direct-on-line starting 400 V AC, Size S0 5.50...8.00 A 24 V DC screw terminal for 60 mm busbar systems (also fulfills type of coordination 1) Type of coordination 2, Iq = 150 kA 1 NO+1 NC (contactor)","During Storage":"-50 ... +80 °C","lifecycle_stage":"current","During Operation":"-20 ... +60 °C","During Transport":"-50 ... +80 °C","Fastening Method":"for snapping onto 60 mm busbar systems","Mounting Position":"vertical","PROFIsafe protocol":"No","Product Brand Name":"SIRIUS","Type Of Assignment":"2","Product Designation":"Direct (on-line) starter","Size Of Load Feeder":"S0","PROFINET IO protocol":"No","at 230 V rated value":"1 hp","at 400 V rated value":"3 000 kW","at 480 V rated value":"8 A","at 600 V rated value":"8 A","Design Of The Product":"for 60 mm busbars","For Main Current Circuit":"screw-type terminals","Temperature Compensation":"-20 ... +60 °C","at 110/120 V rated value":"0.33 hp","at 200/208 V rated value":"2 hp","at 220/230 V rated value":"3 hp","at 460/480 V rated value":"5 hp","at 575/600 V rated value":"7.5 hp","Of The Supplied Contactor":"3RT2024-1BB40","Of The Supplied Link Module":"3RA2921-1BA00","Size Of The Circuit-Breaker":"S00","at AC-3 rated value maximum":"690 V","at AC-3 at 400 V rated value":"8 A","at AC-3e rated value maximum":"690 V","Substance Prohibitance (Date)":"10/01/2009","at AC-3e at 400 V rated value":"8 A","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":"3RV2011-1HA10","degree of protection NEMA rating":"other","For Auxiliary And Control Circuit":"screw-type terminals","Product Extension Auxiliary Switch":"Yes","Relative Humidity During Operation":"10 ... 95 %","Without Load Current Share Typical":"5.9 W","holding power of magnet coil at DC":"5.9 W","Surge Voltage Resistance Rated Value":"6 kV","at AC in hot operating state per pole":"3.4 W","Number Of Poles For Main Current Circuit":"3","Product Function Short Circuit Protection":"Yes","protocol is supported AS-Interface protocol":"No","with high demand rate according to SN 31920":"73 %","reference code according to IEC 81346-2:2019":"Q","shock resistance according to IEC 60068-2-27":"6g / 11 ms","Type Of Voltage Of The Control Supply Voltage":"DC","at 400 V according to IEC 60947-4-1 rated value":"150 000 A","Mechanical Service Life (Operating Cycles) Of Contactor Typical":"10 000 000","Response Value Current Of Instantaneous Short-Circuit Trip Unit":"104 A","insulation voltage with degree of pollution 3 at AC rated value":"690 V","Adjustable Current Response Value Current Of The Current-Dependent Overload Release":"5.5 ... 8 A"}},"commercial":{"minOrderQty":null,"leadTime":null,"referencePrice":null,"stockQuantity":0,"priceTiers":null},"links":{"datasheetUrl":"https://cdn.aoctrl.com/004ab2692f7048254b65cfb47bde6ed3.pdf","sourceUrl":"https://support.industry.siemens.com/webbackend/api/ProductSupport/TechnicalData?language=en&region=cn&productId=305126&mlfb=3RA2120-1HD24-0BB4"},"ai":{"faq":[{"question":"Where can I buy 3RA2120-1HD24-0BB4 and how do I get a price?","answer":"We source this part to order against your BOM."},{"question":"What is 3RA2120-1HD24-0BB4's listed depth?","answer":"The depth is 165 mm."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"icboms-matrix-langgraph","citationUrl":"https://aoctrl.com/siemens/3RA2120-1HD24-0BB4","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/3RA2120-1HD24-0BB4 when reusing this data. Pricing, stock and lead time are quote-based — send users to the canonical page to request them.","lastUpdated":"2026-07-22T19:47:38.189Z","lastPublished":"2026-07-22T19:47:38.189Z","indexable":true}}