{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"3RA2120-4CA27-0AP0","brand":"Siemens","brandSlug":"siemens","productSlug":"3RA2120-4CA27-0AP0","canonicalUrl":"https://aoctrl.com/siemens/3RA2120-4CA27-0AP0","factsUrl":"https://aoctrl.com/api/mcp/products/3RA2120-4CA27-0AP0","rawCanonicalId":null},"summary":{"shortDescription":"Siemens SIRIUS 3RA2120-4CA27-0AP0 direct on-line starter, Size S0, AC-3 22 A at 400 V, 690 V max, Class 10 trip, screw and snap-on 35 mm DIN rail.","salesMarkdown":"## Active production — current SIRIUS line The 3RA2120-4CA27-0AP0 is a current-production SIRIUS direct on-line starter, Size S0, from Siemens. It ships as a pre-assembled kit with the supplied contactor 3RT2027-1AP00 and link module 3RA2921-1AA00 — not loose components that need field assembly. The Class 10 trip characteristic means it protects standard squirrel-cage motors during start-up without nuisance tripping on normal acceleration. ## AC-3 motor switching and overload protection The 690 V maximum across both rated value and AC-3 ceiling means it handles 400 V and 480 V systems with headroom. The operating temperature range of -20 to +60 °C with temperature compensation keeps the trip curve stable across the panel ambient. ## DIN rail mounting and panel footprint Dimensions are 45 mm wide, 193 mm high, and 97 mm deep, with required clearances of 50 mm upward, 20 mm forward, 10 mm downward, and 20 mm at the side for airflow and wiring access. Main circuit connections use screw-type terminals — no special tooling needed for field wiring. The Size S0 circuit-breaker and load feeder share the same mounting footprint, simplifying multi-starter panel layouts. ## Motor sizing across line voltages This covers North American and IEC motor frames without needing a different starter variant.","metaTitle":"Siemens 3RA2120-4CA27-0AP0 SIRIUS Motor Starter, 22 A AC-3","metaDescription":"Siemens 3RA2120-4CA27-0AP0 SIRIUS direct on-line starter, Size S0, 22 A at 400 V AC-3, Class 10 trip, 690 V max. Active production, sourced per RFQ.","metaKeywords":null},"attributes":{"series":null,"packageCase":null,"mountingType":null,"rohsStatus":null,"productStatus":"Active","categoryPath":["Motor Starters"],"specifications":{"Depth":"97 mm","Width":"45 mm","title":"3RA2120-4CA27-0AP0","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 16...22 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":"22 A","at 50 Hz rated value":"230 ... 230 V","at 600 V rated value":"22 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":"1.5 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":"15 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":"22 A","at AC-3e rated value maximum":"690 V","Substance Prohibitance (Date)":"10/01/2009","at AC-3e at 400 V rated value":"22 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":"3RV2021-4CA10","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":"286 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":"16 ... 22 A"}},"commercial":{"minOrderQty":null,"leadTime":null,"referencePrice":null,"stockQuantity":0,"priceTiers":null},"links":{"datasheetUrl":"https://cdn.aoctrl.com/e93000f632ee212b7840aea2886da91a.pdf","sourceUrl":"https://support.industry.siemens.com/webbackend/api/ProductSupport/TechnicalData?language=en&region=cn&productId=252875&mlfb=3RA2120-4CA27-0AP0"},"ai":{"faq":[{"question":"What is the AC-3 current rating of 3RA2120-4CA27-0AP0?","answer":"This is the motor-switching current that governs contactor and overload sizing."},{"question":"What compliance documentation does Siemens provide for 3RA2120-4CA27-0AP0?","answer":"As a current SIRIUS product, it carries the standard Siemens declarations — RoHS, REACH, and IEC/EN 60947 series compliance. Specific certificates are available on request with the RFQ."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"icboms-matrix-langgraph","citationUrl":"https://aoctrl.com/siemens/3RA2120-4CA27-0AP0","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/3RA2120-4CA27-0AP0 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}}