{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"3RA2120-4NA27-0AP0","brand":"Siemens","brandSlug":"siemens","productSlug":"3RA2120-4NA27-0AP0","canonicalUrl":"https://aoctrl.com/siemens/3RA2120-4NA27-0AP0","factsUrl":"https://aoctrl.com/api/mcp/products/3RA2120-4NA27-0AP0","rawCanonicalId":null},"summary":{"shortDescription":"Siemens SIRIUS 3RA2120-4NA27-0AP0 direct online motor starter, AC-3 28 A at 400 V, 690 V max, Trip Class 10, S0 size, screw and snap-on 35 mm DIN rail, 45 x 97 x 193 mm.","salesMarkdown":"## What the 28 A AC-3 rating means for your motor load The 3RA2120-4NA27-0AP0: At 480 V it delivers 27 A, and at 600 V it holds 27 A as well, so the current ceiling is consistent across common North American line voltages. ## DIN-rail fit and panel clearance Width is 45 mm — that's a single 9 mm DIN-rail module slot, so it fits tightly in a crowded panel. Depth is 97 mm, height 193 mm. Clearance requirements: 50 mm upwards, 20 mm forwards, 20 mm at the side, 10 mm downwards, and 0 mm backwards — so the back of the starter can sit flush against the panel backplate. ## What's in the box — supplied contactor and link module The starter ships with a 3RT2027-1AP00 contactor and a 3RA2921-1AA00 link module already integrated. That means it's a factory-assembled combination — no separate ordering of the contactor and overload relay, and the wiring between them is done via the link module. Main circuit terminals are screw-type, so you'll need a screwdriver for the power connections. The load feeder size is S0, and the circuit-breaker size is also S0 — consistent with the frame. ## Temperature range and storage Operating ambient is -20 to +60 °C, storage and transport -50 to +80 °C. Temperature compensation is active across the operating range, so the overload curve stays accurate without manual adjustment.","metaTitle":"Siemens 3RA2120-4NA27-0AP0 SIRIUS Motor Starter, 28 A AC-3","metaDescription":"Siemens SIRIUS 3RA2120-4NA27-0AP0 direct online motor starter, 28 A AC-3 at 400 V, 690 V max, Class 10, S0 size, DIN rail. Active production, quoted to order.","metaKeywords":null},"attributes":{"series":null,"packageCase":null,"mountingType":null,"rohsStatus":null,"productStatus":"Active","categoryPath":["Motor Starters"],"specifications":{"Depth":"97 mm","Width":"45 mm","title":"3RA2120-4NA27-0AP0","Height":"193 mm","Upwards":"50 mm","Forwards":"20 mm","at 50 Hz":"0.25","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 screw terminal for installation on standard mounting rail (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":"screw and snap-on mounting onto 35 mm DIN 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 230 V rated value":"5 hp","at 400 V rated value":"15 000 kW","at 480 V rated value":"27 A","at 50 Hz rated value":"230 ... 230 V","at 600 V rated value":"27 A","Design Of The Product":"for standard rail or screw mounting","For Main Current Circuit":"screw-type terminals","Temperature Compensation":"-20 ... +60 °C","at 110/120 V rated value":"2 hp","at 200/208 V rated value":"7.5 hp","at 220/230 V rated value":"10 hp","at 460/480 V rated value":"20 hp","Of The Supplied Contactor":"3RT2027-1AP00","Of The Supplied Link Module":"3RA2921-1AA00","Size Of The Circuit-Breaker":"S0","at AC-3 rated value maximum":"690 V","at AC-3 at 400 V rated value":"28 A","at AC-3e rated value maximum":"690 V","Substance Prohibitance (Date)":"10/01/2009","at AC-3e at 400 V rated value":"28 A","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":"3RV2021-4NA10","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":"9.8 W","Surge Voltage Resistance Rated Value":"6 kV","at AC in hot operating state per pole":"6.7 W","Number Of Poles For Main Current Circuit":"3","Product Function Short Circuit Protection":"Yes","apparent holding power of magnet coil at AC":"9.8 VA","protocol is supported AS-Interface protocol":"No","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":"AC","at 400 V according to IEC 60947-4-1 rated value":"150 000 A","Inductive Power Factor With The Holding Power Of The Coil":"0.25","Mechanical Service Life (Operating Cycles) Of Contactor Typical":"10 000 000","Response Value Current Of Instantaneous Short-Circuit Trip Unit":"364 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":"23 ... 28 A"}},"commercial":{"minOrderQty":null,"leadTime":null,"referencePrice":null,"stockQuantity":0,"priceTiers":null},"links":{"datasheetUrl":"https://cdn.aoctrl.com/8544926e9139336afbe0f98df9515a88.pdf","sourceUrl":"https://support.industry.siemens.com/webbackend/api/ProductSupport/TechnicalData?language=en&region=cn&productId=9944&mlfb=3RA2120-4NA27-0AP0"},"ai":{"faq":[{"question":"What is the AC-3 current rating at 400 V for this starter?","answer":"At 480 V and 600 V it delivers 27 A."},{"question":"What panel clearances are needed around this starter?","answer":"Allow 50 mm upwards, 20 mm forwards, 20 mm at the side, 10 mm downwards, and 0 mm backwards. The back can sit flush against the panel."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"icboms-matrix-langgraph","citationUrl":"https://aoctrl.com/siemens/3RA2120-4NA27-0AP0","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/3RA2120-4NA27-0AP0 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}}