{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"3RA2120-4BD26-0AP0","brand":"Siemens","brandSlug":"siemens","productSlug":"3RA2120-4BD26-0AP0","canonicalUrl":"https://aoctrl.com/siemens/3RA2120-4BD26-0AP0","factsUrl":"https://aoctrl.com/api/mcp/products/3RA2120-4BD26-0AP0","rawCanonicalId":null},"summary":{"shortDescription":"Siemens SIRIUS 3RA2120-4BD26-0AP0 direct-on-line motor starter, Size S0, 20 A at 400 V AC-3, Trip Class 10, 690 V rated, for 60 mm busbar systems.","salesMarkdown":"## SIRIUS S0 direct-on-line starter — 20 A AC-3, snap-on busbar mount The 3RA2120-4BD26-0AP0: Trip Class 10 means it protects standard squirrel-cage motors during start-up without nuisance tripping on normal inrush. The unit snaps onto 60 mm busbar systems — the fastening method is designed for that specific busbar pitch, so it integrates into panel builds using that spacing without extra brackets. Mounting position is vertical only. It ships with the contactor 3RT2026-1AP00 and the link module 3RA2921-1AA00 pre-assembled — no separate ordering of those components for the basic starter function. Main circuit terminals are screw-type. ## Rated voltage envelope and temperature range The AC-3 maximum operating voltage is also 690 V — the full voltage rating applies across the motor-switching duty. Operating temperature range is -20 to +60 °C with temperature compensation active across that band. Storage and transport limits are -50 to +80 °C. The compensation ensures the trip curve stays consistent across the working ambient range. Dimensions are 155 mm deep, 45 mm wide, 260 mm tall — the width is the panel-space footprint on the busbar. Clearance requirements: 50 mm upwards, 20 mm forwards, 10 mm downwards, 20 mm at the side, zero backwards. ## Active production — sourcing posture No stock-holding claim — quoted to order per RFQ.","metaTitle":"Siemens 3RA2120-4BD26-0AP0 SIRIUS Motor Starter, 20 A AC-3","metaDescription":"Siemens 3RA2120-4BD26-0AP0 SIRIUS direct-on-line starter, 20 A at 400 V AC-3, Size S0, Trip Class 10. Active production, quoted to order.","metaKeywords":null},"attributes":{"series":null,"packageCase":null,"mountingType":null,"rohsStatus":null,"productStatus":"Active","categoryPath":["Motor Starters"],"specifications":{"Depth":"155 mm","Width":"45 mm","title":"3RA2120-4BD26-0AP0","Height":"260 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 13...20 A 230 V AC screw terminal for 60 mm busbar systems Type of coordination 1, 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":"1","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 60 mm busbars","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":"5 hp","at 220/230 V rated value":"7.5 hp","at 460/480 V rated value":"15 hp","Of The Supplied Contactor":"3RT2026-1AP00","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)","Of The Supplied Busbar Adapter":"8US1251-5NT10","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":"5.4 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":null,"stockQuantity":0,"priceTiers":null},"links":{"datasheetUrl":"https://cdn.aoctrl.com/1fc90508ec487492e81c6b1b10ffe3db.pdf","sourceUrl":"https://support.industry.siemens.com/webbackend/api/ProductSupport/TechnicalData?language=en&region=cn&productId=183060&mlfb=3RA2120-4BD26-0AP0"},"ai":{"faq":[{"question":"What is the AC-3 rating of the 3RA2120-4BD26-0AP0 at 400 V?","answer":"Trip Class 10 protects standard motors during start-up."},{"question":"Does the 3RA2120-4BD26-0AP0 mount on standard DIN rail or busbars?","answer":"This starter is designed for snapping onto 60 mm busbar systems, not standard 35 mm DIN rail. Mounting position is vertical only."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"icboms-matrix-langgraph","citationUrl":"https://aoctrl.com/siemens/3RA2120-4BD26-0AP0","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/3RA2120-4BD26-0AP0 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}}