{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"3RA2120-4NH27-0AP0","brand":"Siemens","brandSlug":"siemens","productSlug":"3RA2120-4NH27-0AP0","canonicalUrl":"https://aoctrl.com/siemens/3RA2120-4NH27-0AP0","factsUrl":"https://aoctrl.com/api/mcp/products/3RA2120-4NH27-0AP0","rawCanonicalId":null},"summary":{"shortDescription":"Siemens SIRIUS 3RA2120-4NH27-0AP0 direct-on-line motor starter, size S0, 15 kW at 400 V AC-3, Class 10 thermal overload, spring-loaded terminals, snaps onto 60 mm busbar systems.","salesMarkdown":"## Busbar-mounted DOL starter, 15 kW at 400 V The 3RA2120-4NH27-0AP0: It snaps onto 60 mm busbar systems via the supplied busbar adapter (8US1251-5NT11), not a DIN rail — the mounting foot is built for the busbar profile, so panel layout needs that clearance. The assembly ships with the contactor (3RT2027-2AP00), the thermal bimetallic overload relay (Class 10), and the circuit-breaker (3RV2021-4NA20) pre-matched — one order code, one BOM line, no separate sizing. ## Dimensions and panel fit — vertical mount only The starter measures 45 mm wide, 260 mm high, and 165 mm deep — the width fits a standard 45 mm busbar slot; the height and depth demand vertical mounting with 50 mm clearance above and 20 mm in front for terminal access and cooling airflow. Side clearance is 20 mm; no clearance needed behind (0 mm backwards). Operating temperature range is -20 to +60 °C, storage -50 to +80 °C — fine for most industrial enclosures; derate if ambient exceeds 60 °C. ## Protection and trip coordination The thermal bimetallic element tracks motor heating; the magnetic short-circuit trip in the breaker handles fault clearing. Rated insulation voltage is 690 V, so it works on 400 V, 480 V, and 690 V line systems. The operating frequency is 50/60 Hz — global line compatibility without derating.","metaTitle":"Siemens 3RA2120-4NH27-0AP0 SIRIUS Motor Starter","metaDescription":"Siemens 3RA2120-4NH27-0AP0 SIRIUS direct-on-line starter, 15 kW at 400 V AC-3, Class 10, snaps onto 60 mm busbars. Active production, sourced per RFQ.","metaKeywords":null},"attributes":{"series":null,"packageCase":null,"mountingType":null,"rohsStatus":null,"productStatus":"Active","categoryPath":["Motor Starters"],"specifications":{"Depth":"165 mm","Width":"45 mm","title":"3RA2120-4NH27-0AP0","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 23.0...28.0 A 230 V AC 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":"15 000 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":"3RT2027-2AP00","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":"3RV2021-4NA20","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":"28 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":"23 ... 28 A"}},"commercial":{"minOrderQty":null,"leadTime":null,"referencePrice":null,"stockQuantity":0,"priceTiers":null},"links":{"datasheetUrl":"https://cdn.aoctrl.com/f8e7d64f561302911931bbacbc6cde0e.pdf","sourceUrl":"https://support.industry.siemens.com/webbackend/api/ProductSupport/TechnicalData?language=en&region=cn&productId=504044&mlfb=3RA2120-4NH27-0AP0"},"ai":{"faq":[{"question":"What does the 15 kW at 400 V rating mean for motor sizing?","answer":"The Class 10 overload protects motors that accelerate to full speed within 10 seconds — typical for pumps, fans, and light conveyors. For heavier starts (high inertia or long ramp), a Class 20 or electronic overload may be needed."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"icboms-matrix-langgraph","citationUrl":"https://aoctrl.com/siemens/3RA2120-4NH27-0AP0","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/3RA2120-4NH27-0AP0 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}}