{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"3RA2120-4DA27-0FB4","brand":"Siemens","brandSlug":"siemens","productSlug":"3RA2120-4DA27-0FB4","canonicalUrl":"https://aoctrl.com/siemens/3RA2120-4DA27-0FB4","factsUrl":"https://aoctrl.com/api/mcp/products/3RA2120-4DA27-0FB4","rawCanonicalId":null},"summary":{"shortDescription":"Siemens SIRIUS 3RA2120-4DA27-0FB4 direct online starter, Size S0, 11 kW at 400 V AC-3, Class 10, 24 V DC coil, screw terminals, 45 x 193 x 107 mm.","salesMarkdown":"## What this SIRIUS starter packs The Siemens 3RA2120-4DA27-0FB4 is a SIRIUS direct online starter — a factory-assembled combination of a contactor, thermal overload relay, and circuit breaker in one S0-size package. The built-in overload is thermal bimetallic (Class 10 trip), and the short-circuit protection is magnetic — the supplied circuit breaker is a 3RV2021-4DA10. That means it coordinates the motor branch without needing separate components. ## Mounting and panel fit Mounts on 35 mm DIN rail with a snap-on foot, or directly with screws — the S0 footprint is 45 mm wide, 193 mm tall, and 107 mm deep. The vertical mounting position is specified, and clearance around the unit matters: 50 mm above, 20 mm in front, 20 mm to the side, and 10 mm below. No clearance needed behind the rail. Both the main and control circuits use screw-type terminals — no special tooling needed, just a screwdriver. The control coil is 24 V DC, drawing 5.9 W holding power.","metaTitle":"Siemens 3RA2120-4DA27-0FB4 direct starter, 11 kW at 400 V","metaDescription":"Siemens SIRIUS 3RA2120-4DA27-0FB4 direct online starter, 11 kW at 400 V AC-3, Class 10, S0 size. Active production, available to order. Quoted against RFQ.","metaKeywords":null},"attributes":{"series":null,"packageCase":null,"mountingType":null,"rohsStatus":null,"productStatus":"Active","categoryPath":["Motor Starters"],"specifications":{"Depth":"107 mm","Width":"45 mm","Height":"193 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","During Storage":"-50 ... +80 °C","lifecycle_stage":"current","During Operation":"-20 ... +60 °C","During Transport":"-50 ... +80 °C","Fastening Method":"screw and snap-on mounting onto 35 mm standard mounting rail","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 400 V rated value":"11 000 W","Design Of The Product":"for standard rail or screw mounting","For Main Current Circuit":"screw-type terminals","Temperature Compensation":"-20 ... +60 °C","Of The Supplied Contactor":"3RT2027-1FB40","Of The Supplied Link Module":"3RA2921-1BA00","Size Of The Circuit-Breaker":"S0","at AC-3 rated value maximum":"690 V","Design Of The Overload Release":"thermal (bimetallic)","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":"3RV2021-4DA10","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 %","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","protocol is supported AS-Interface protocol":"No","with high demand rate according to SN 31920":"73 %","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","operational current at AC-3 at 400 V rated value":"22 A","Mechanical Service Life (Switching Cycles) Of Contactor Typical":"10 000 000","insulation voltage with degree of pollution 3 at AC rated value":"690 V","Adjustable Current Response Value Current Of The Current-Dependent Overload Release":"18 ... 25 A"}},"commercial":{"minOrderQty":null,"leadTime":null,"referencePrice":null,"priceTiers":null},"links":{"datasheetUrl":"https://cdn.aoctrl.com/e749c5681bfa5d3ca0d9be17d327ebb2.pdf","sourceUrl":"https://support.industry.siemens.com/webbackend/api/ProductSupport/TechnicalData?language=en&region=cn&productId=207034&mlfb=3RA2120-4DA27-0FB4","alternativesUrl":"https://aoctrl.com/api/mcp/products/3RA2120-4DA27-0FB4/alternatives.json"},"ai":{"faq":[{"question":"What is the price and availability for 3RA2120-4DA27-0FB4?","answer":"Pricing and current stock levels are confirmed at quote time. Submit an RFQ with your target quantity and ship-to location — we'll return a firm quote with lead time from authorized Siemens distribution."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"matrix-langgraph","citationUrl":"https://aoctrl.com/siemens/3RA2120-4DA27-0FB4","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/3RA2120-4DA27-0FB4 when reusing this data. Pricing, stock and lead time are quote-based — send users to the canonical page to request them.","lastUpdated":"2026-09-02T08:15:54.622Z","lastPublished":"2026-09-02T08:15:54.622Z","indexable":true}}