{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"3RA2120-1KD24-0FB4","brand":"Siemens","brandSlug":"siemens","productSlug":"3RA2120-1KD24-0FB4","canonicalUrl":"https://aoctrl.com/siemens/3RA2120-1KD24-0FB4","factsUrl":"https://aoctrl.com/api/mcp/products/3RA2120-1KD24-0FB4","rawCanonicalId":null},"summary":{"shortDescription":"Siemens SIRIUS 3RA2120-1KD24-0FB4 direct-on-line starter, Size S0, 5.5 kW at 400 V, 11 A at 480 V, Class 10, 24 V DC coil, for 60 mm busbar systems.","salesMarkdown":"## Mounting and panel fit — busbar snap-on The 3RA2120-1KD24-0FB4: Designed for snapping onto 60 mm busbar systems, the 45 mm width and 260 mm height fit a standard S0 feeder footprint — the 165 mm depth leaves room for wiring ducts in a 400 mm deep enclosure. Clearance requirements: 50 mm above, 20 mm in front, 20 mm at the sides, and 10 mm below — no clearance needed at the back. The vertical mounting position is mandatory for proper thermal bi-metallic release operation. ## Protection and termination details The thermal bimetallic overload release provides adjustable overload protection; the magnetic short-circuit trip handles fault interruption. Main circuit connections are screw-type terminals — no special tooling needed for field wiring. Supplied as a complete assembly: contactor 3RT2024-1FB40, link module 3RA2921-1BA00, and busbar adapter 8US1251-5NT10 — all pre-configured for 60 mm busbar mounting. ## Environmental limits and storage Operates from -20 to +60 °C with temperature compensation; storage and transport range is -50 to +80 °C. The 24 V DC coil is rated at 24 V nominal — confirm the control supply matches the solenoid draw.","metaTitle":"Siemens 3RA2120-1KD24-0FB4 SIRIUS Direct Starter","metaDescription":"Siemens 3RA2120-1KD24-0FB4 SIRIUS direct-on-line starter, 5.5 kW at 400 V, Class 10, for 60 mm busbar systems. Active production; sourced 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":"3RA2120-1KD24-0FB4","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 9.00...12.5 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) with diode combination plugged in at the front","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 400 V rated value":"5 500 W","at 480 V rated value":"11 A","Design Of The Product":"for 60 mm busbars","For Main Current Circuit":"screw-type terminals","Temperature Compensation":"-20 ... +60 °C","at 200/208 V rated value":"3 hp","at 220/230 V rated value":"3 hp","at 460/480 V rated value":"7.5 hp","at 575/600 V rated value":"10 hp","Of The Supplied Contactor":"3RT2024-1FB40","Of The Supplied Link Module":"3RA2921-1BA00","Size Of The Circuit-Breaker":"S00","at AC-3 rated value maximum":"690 V","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":"3RV2011-1KA10","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":"11.5 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":"9 ... 12.5 A"}},"commercial":{"minOrderQty":null,"leadTime":null,"referencePrice":null,"stockQuantity":0,"priceTiers":null},"links":{"datasheetUrl":"https://cdn.aoctrl.com/5045611d17c99d5dafd1f7f668e2cc32.pdf","sourceUrl":"https://support.industry.siemens.com/webbackend/api/ProductSupport/TechnicalData?language=en&region=cn&productId=45483&mlfb=3RA2120-1KD24-0FB4"},"ai":{"faq":[{"question":"What are the key ratings for 3RA2120-1KD24-0FB4?","answer":"The coil is 24 V DC. It mounts on 60 mm busbar systems and measures 45 mm wide × 260 mm high × 165 mm deep."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"icboms-matrix-langgraph","citationUrl":"https://aoctrl.com/siemens/3RA2120-1KD24-0FB4","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/3RA2120-1KD24-0FB4 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}}