{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"3RA2120-4BA27-0AP0","brand":"Siemens","brandSlug":"siemens","productSlug":"3RA2120-4BA27-0AP0","canonicalUrl":"https://aoctrl.com/siemens/3RA2120-4BA27-0AP0","factsUrl":"https://aoctrl.com/api/mcp/products/3RA2120-4BA27-0AP0","rawCanonicalId":null},"summary":{"shortDescription":"Siemens SIRIUS S0 direct on-line starter, 3RA2120-4BA27-0AP0, 20 A at 400 V AC-3, 690 V max, Class 10, screw terminals, 45 mm width, 97 mm depth, DIN rail mount.","salesMarkdown":"## AC-3 motor rating that decides the fit The 3RA2120-4BA27-0AP0: No PROFIsafe or PROFINET IO on this variant. ## What the assembly includes and how it mounts This is a direct on-line starter in the SIRIUS S0 frame size. It ships with a 3RT2027-1AP00 contactor and a 3RA2921-1AA00 link module — the overload relay and contactor arrive as a pre-assembled unit, not loose parts. The 45 mm width and 97 mm depth fit the S0 footprint; clearance needs are 50 mm upwards, 20 mm forwards, 10 mm downwards, and 20 mm at the sides for wiring and heat dissipation. Main circuit terminals are screw-type. ## Lifecycle and sourcing — current production, quoted to order Sourced through authorized distribution; availability and volume pricing confirmed against an RFQ at quote time. The spread is the business — this one ships clean from a reliable supply channel.","metaTitle":"Siemens 3RA2120-4BA27-0AP0 SIRIUS Motor Starter, 20 A AC-3","metaDescription":"Siemens 3RA2120-4BA27-0AP0 SIRIUS S0 direct on-line starter, 20 A at 400 V AC-3, Class 10, 690 V max. Screw terminals, DIN rail mount.","metaKeywords":null},"attributes":{"series":null,"packageCase":null,"mountingType":null,"rohsStatus":null,"productStatus":"Active","categoryPath":["Motor Starters"],"specifications":{"Depth":"97 mm","Width":"45 mm","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","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":"7 500 kW","at 480 V rated value":"20 A","at 50 Hz rated value":"230 ... 230 V","at 600 V rated value":"20 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":"20 A","at AC-3e rated value maximum":"690 V","Substance Prohibitance (Date)":"10/01/2009","at AC-3e at 400 V rated value":"20 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":"3RV2021-4BA10","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":"260 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":"13 ... 20 A"}},"commercial":{"minOrderQty":null,"leadTime":null,"referencePrice":"$121.92","priceTiers":null},"links":{"datasheetUrl":"https://cdn.aoctrl.com/31f542d5d446b8d28c150e7e787a487b.pdf","sourceUrl":"https://support.industry.siemens.com/webbackend/api/ProductSupport/TechnicalData?language=en&region=cn&productId=168513&mlfb=3RA2120-4BA27-0AP0","alternativesUrl":"https://aoctrl.com/api/mcp/products/3RA2120-4BA27-0AP0/alternatives.json"},"ai":{"faq":[],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"matrix-langgraph","citationUrl":"https://aoctrl.com/siemens/3RA2120-4BA27-0AP0","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/3RA2120-4BA27-0AP0 when reusing this data. Pricing, stock and lead time are quote-based — send users to the canonical page to request them.","lastUpdated":"2026-09-02T08:15:54.622Z","lastPublished":"2026-09-02T08:15:54.622Z","indexable":true}}