{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"3RA2120-4DA27-0AP0","brand":"Siemens","brandSlug":"siemens","productSlug":"3RA2120-4DA27-0AP0","canonicalUrl":"https://aoctrl.com/siemens/3RA2120-4DA27-0AP0","factsUrl":"https://aoctrl.com/api/mcp/products/3RA2120-4DA27-0AP0","rawCanonicalId":null},"summary":{"shortDescription":"Siemens SIRIUS 3RA2120-4DA27-0AP0 direct-on-line starter, size S0, 25 A at 400 V AC-3, Class 10 trip, screw-type terminals, 45 x 97 x 193 mm, screw and snap-on mounting onto 35 mm DIN rail.","salesMarkdown":"The 3RA2120-4DA27-0AP0: The operating temperature range is -20 to +60 °C, with storage and transport tolerance from -50 to +80 °C. Temperature compensation is active across the full operating band. ## AC-3 motor duty and trip class The maximum AC-3 operating voltage is 690 V. ## Panel integration — size S0, DIN rail mount Size S0 load feeder, 45 mm wide, 97 mm deep, 193 mm tall. Mounts vertically on 35 mm DIN rail using the screw-and-snap-on method; the fastening design also accepts screw mounting for backplate installations. Clearance requirements: 50 mm upwards, 20 mm forwards, 10 mm downwards, 20 mm at the side, 0 mm backwards. These are the minimum air gaps for heat dissipation and cable entry — respect them in the enclosure layout. Main circuit connections use screw-type terminals — no special tooling needed, but torque to the manufacturer specification during commissioning. ## Supplied components — contactor and link module This starter ships with the 3RT2027-1AP00 contactor and the 3RA2921-1AA00 link module pre-assembled. The contactor is the switching element; the link module integrates the overload relay and wiring interface into one package. The supplied contactor carries the same AC-3 rating as the assembled starter — 25 A at 400 V — so the combination is matched for motor starting duty without derating.","metaTitle":"Siemens 3RA2120-4DA27-0AP0 SIRIUS Direct Starter, 25 A AC-3","metaDescription":"Siemens SIRIUS 3RA2120-4DA27-0AP0 direct-on-line starter, 25 A at 400 V AC-3, Class 10, size S0. Active production, screw/snap-on 35 mm DIN rail.","metaKeywords":null},"attributes":{"series":null,"packageCase":null,"mountingType":null,"rohsStatus":null,"productStatus":"Active","categoryPath":["Motor Starters"],"specifications":{"Depth":"97 mm","Width":"45 mm","title":"3RA2120-4DA27-0AP0","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 18...25 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":"3 hp","at 400 V rated value":"11 000 kW","at 480 V rated value":"25 A","at 50 Hz rated value":"230 ... 230 V","at 600 V rated value":"25 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":"7.5 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":"25 A","at AC-3e rated value maximum":"690 V","Substance Prohibitance (Date)":"10/01/2009","at AC-3e at 400 V rated value":"25 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":"3RV2021-4DA10","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 %","Without Load Current Share Typical":"9.8 W","Surge Voltage Resistance Rated Value":"6 kV","at AC in hot operating state per pole":"5.8 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","with high demand rate according to SN 31920":"73 %","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":"325 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":"18 ... 25 A"}},"commercial":{"minOrderQty":null,"leadTime":null,"referencePrice":null,"stockQuantity":0,"priceTiers":null},"links":{"datasheetUrl":"https://cdn.aoctrl.com/e1e9051b3dc15f590bbb6d558dfdfae4.pdf","sourceUrl":"https://support.industry.siemens.com/webbackend/api/ProductSupport/TechnicalData?language=en&region=cn&productId=128189&mlfb=3RA2120-4DA27-0AP0"},"ai":{"faq":[{"question":"Where can I buy 3RA2120-4DA27-0AP0 and how do I get a price?","answer":"This starter is available through independent distribution channels. No stock-holding claim is made — each order is sourced per request."},{"question":"What is the AC-3 rating of 3RA2120-4DA27-0AP0 at 400 V?","answer":"This is the motor-switching current for standard squirrel-cage induction motors."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"icboms-matrix-langgraph","citationUrl":"https://aoctrl.com/siemens/3RA2120-4DA27-0AP0","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/3RA2120-4DA27-0AP0 when reusing this data. Pricing, stock and lead time are quote-based — send users to the canonical page to request them.","lastUpdated":"2026-08-11T15:51:03.652Z","lastPublished":"2026-08-11T15:51:03.652Z","indexable":true}}