{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"3RA2120-4AA26-0FB4","brand":"Siemens","brandSlug":"siemens","productSlug":"3RA2120-4AA26-0FB4","canonicalUrl":"https://aoctrl.com/siemens/3RA2120-4AA26-0FB4","factsUrl":"https://aoctrl.com/api/mcp/products/3RA2120-4AA26-0FB4","rawCanonicalId":null},"summary":{"shortDescription":"Siemens SIRIUS 3RA2120-4AA26-0FB4 direct-on-line motor starter, Size S0, 16 A at AC-3 400 V, Class 10 trip, screw and snap-on DIN rail mount.","salesMarkdown":"## What the 16 A AC-3 rating means for your motor feeder The 3RA2120-4AA26-0FB4 is a SIRIUS direct-on-line starter — a pre-assembled combination of a contactor and overload relay in one Size S0 housing, rated 16 A at AC-3 at 400 V for switching squirrel-cage motors under full-voltage starting. ## Panel fit and mounting — Size S0 on DIN rail Clearance requirements: 50 mm upwards, 20 mm forwards, 10 mm downwards, 20 mm at the side, and 0 mm backwards — the back is flush to the mounting surface, so no rear clearance is needed. Overall dimensions are 107 mm depth × 45 mm width × 193 mm height — the depth is the critical dimension for shallow enclosures, as the starter protrudes 107 mm from the DIN rail face. ## Built-in components and wiring The unit ships with the 3RT2026-1FB40 contactor and the 3RA2921-1BA00 link module pre-assembled — no separate ordering of contactor and overload for this combination. Main circuit connections use screw-type terminals, and the circuit-breaker size matches the S0 feeder frame — the entire power path from breaker to contactor to overload is contained within the 45 mm width. Operating temperature range is -20 to +60 °C with temperature compensation active across the same span — the starter's thermal calibration stays accurate across the full ambient range. RoHS compliance is indicated by the substance prohibitance date of 10/01/2009 — the starter meets the EU RoHS directive effective from that date.","metaTitle":"Siemens 3RA2120-4AA26-0FB4 SIRIUS Motor Starter, 16 A AC-3","metaDescription":"Siemens 3RA2120-4AA26-0FB4 SIRIUS direct-on-line starter, 16 A at AC-3 400 V, Class 10 trip, Size S0. Active production. Quoted to order against RFQ.","metaKeywords":null},"attributes":{"series":null,"packageCase":null,"mountingType":null,"rohsStatus":null,"productStatus":"Active","categoryPath":["Motor Starters"],"specifications":{"Depth":"107 mm","Width":"45 mm","Height":"193 mm","Upwards":"50 mm","Forwards":"20 mm","Backwards":"0 mm","Downwards":"10 mm","Trip Class":"CLASS 10","At The Side":"20 mm","Rated Value":"24 ... 24 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":"2 hp","at 400 V rated value":"7 500 kW","at 480 V rated value":"16 A","at 600 V rated value":"16 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 hp","at 200/208 V rated value":"2 hp","at 220/230 V rated value":"5 hp","at 460/480 V rated value":"10 hp","Of The Supplied Contactor":"3RT2026-1FB40","Of The Supplied Link Module":"3RA2921-1BA00","Size Of The Circuit-Breaker":"S0","at AC-3 rated value maximum":"690 V","at AC-3 at 400 V rated value":"16 A","at AC-3e rated value maximum":"690 V","Substance Prohibitance (Date)":"10/01/2009","at AC-3e at 400 V rated value":"16 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":"3RV2021-4AA10","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":"5.9 W","holding power of magnet coil at DC":"5.9 W","Surge Voltage Resistance Rated Value":"6 kV","at AC in hot operating state per pole":"5 W","Number Of Poles For Main Current Circuit":"3","Product Function Short Circuit Protection":"Yes","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":"DC","at 400 V according to IEC 60947-4-1 rated value":"150 000 A","Mechanical Service Life (Operating Cycles) Of Contactor Typical":"10 000 000","Response Value Current Of Instantaneous Short-Circuit Trip Unit":"208 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":"10 ... 16 A"}},"commercial":{"minOrderQty":null,"leadTime":null,"referencePrice":null,"priceTiers":null},"links":{"datasheetUrl":"https://cdn.aoctrl.com/1e40bec8ccc3798d53eca7f2a12b502e.pdf","sourceUrl":"https://support.industry.siemens.com/webbackend/api/ProductSupport/TechnicalData?language=en&region=cn&productId=312468&mlfb=3RA2120-4AA26-0FB4","alternativesUrl":"https://aoctrl.com/api/mcp/products/3RA2120-4AA26-0FB4/alternatives.json"},"ai":{"faq":[],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"matrix-langgraph","citationUrl":"https://aoctrl.com/siemens/3RA2120-4AA26-0FB4","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/3RA2120-4AA26-0FB4 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}}