{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"3RA2120-4DH27-0AV0","brand":"Siemens","brandSlug":"siemens","productSlug":"3RA2120-4DH27-0AV0","canonicalUrl":"https://aoctrl.com/siemens/3RA2120-4DH27-0AV0","factsUrl":"https://aoctrl.com/api/mcp/products/3RA2120-4DH27-0AV0","rawCanonicalId":null},"summary":{"shortDescription":"Siemens SIRIUS direct-on-line starter, S0 size, 11 kW at 400 V AC-3, Class 10, for 60 mm busbar systems, spring-loaded terminals.","salesMarkdown":"The 3RA2120-4DH27-0AV0: This SIRIUS direct-on-line starter is rated 11,000 W at 400 V, 50-60 Hz, with a maximum switching voltage of 690 V AC-3. That 11 kW figure at 400 V is the AC-3 motor rating — it's the current a three-phase squirrel-cage motor draws during starting and running, not a resistive load. If your motor nameplate says 11 kW at 400 V, this starter fits without derating. This protects standard motors during a stalled-rotor condition — Class 10 is the common default for general-purpose induction motors on conveyors, pumps, and fans. A higher class (20 or 30) allows longer start times for high-inertia loads, but Class 10 covers the majority of fixed-speed motor starts. The starter ships with a 3RT2027-2AV00 contactor and a 3RV2021-4DA20 circuit breaker, both spring-loaded for the main and auxiliary/control circuits. The supplied busbar adapter (8US1251-5NT11) and link module (3RA2921-2AA00) are included — no separate ordering for the busbar interface. ## Snaps onto 60 mm busbars — panel layout constraints Designed for snapping onto 60 mm busbar systems, this starter mounts vertically with a fastening method that clips directly onto standard 60 mm busbars. No DIN rail adapter is needed — the busbar adapter (8US1251-5NT11) is already supplied. Dimensions: 165 mm depth, 45 mm width, 260 mm height. Clearance requirements: 50 mm upwards, 20 mm forwards, 0 mm backwards, 10 mm downwards, 20 mm at the side. The zero backwards clearance means it can sit flush against a panel backplate — useful when sliding into a tight enclosure. The 45 mm width (roughly 1.75 inches) fits standard S0 feeder slots.","metaTitle":"Siemens 3RA2120-4DH27-0AV0 SIRIUS Direct Starter","metaDescription":"Siemens 3RA2120-4DH27-0AV0 SIRIUS direct-on-line starter, 11 kW at 400 V AC-3, Class 10, S0 size. 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":"3RA2120-4DH27-0AV0","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":"690 V","description":"Load feeder fuseless, Direct-on-line starting 400 V AC, Size S0 18...25 A Spring-type 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 400 V rated value":"11 000 W","at 50 Hz rated value":"230 ... 230 V","Design Of The Product":"for 60 mm busbars","For Main Current Circuit":"spring-loaded terminals","Temperature Compensation":"-20 ... +60 °C","Of The Supplied Contactor":"3RT2027-2AV00","Of The Supplied Link Module":"3RA2921-2AA00","Size Of The Circuit-Breaker":"S0","at AC-3 rated value maximum":"690 V","Substance Prohibitance (Date)":"10/01/2009","Design Of The Overload Release":"thermal (bimetallic)","Of The Supplied Busbar Adapter":"8US1251-5NT11","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":"3RV2021-4DA20","degree of protection NEMA rating":"other","For Auxiliary And Control Circuit":"spring-loaded terminals","Product Extension Auxiliary Switch":"Yes","Relative Humidity During Operation":"10 ... 95 %","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","shock resistance according to IEC 60068-2-27":"6g / 11 ms","Type Of Voltage Of The Control Supply Voltage":"AC","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,"stockQuantity":0,"priceTiers":null},"links":{"datasheetUrl":"https://cdn.aoctrl.com/30c468a8edc6b5e02c0db115feaf9e43.pdf","sourceUrl":"https://support.industry.siemens.com/webbackend/api/ProductSupport/TechnicalData?language=en&region=cn&productId=572560&mlfb=3RA2120-4DH27-0AV0"},"ai":{"faq":[{"question":"What is the 11 kW rating at 400 V for this starter?","answer":"The 11 kW at 400 V is the AC-3 motor rating — it specifies the maximum three-phase induction motor power the starter can switch and protect under normal starting and running conditions. AC-3 covers starting currents up to 7-8× full load and breaking the motor at full load. If your motor nameplate matches 11 kW at 400 V, this part is the correct fit."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"icboms-matrix-langgraph","citationUrl":"https://aoctrl.com/siemens/3RA2120-4DH27-0AV0","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/3RA2120-4DH27-0AV0 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}}