{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"3RA2120-1KE24-0BB4","brand":"Siemens","brandSlug":"siemens","productSlug":"3RA2120-1KE24-0BB4","canonicalUrl":"https://aoctrl.com/siemens/3RA2120-1KE24-0BB4","factsUrl":"https://aoctrl.com/api/mcp/products/3RA2120-1KE24-0BB4","rawCanonicalId":null},"summary":{"shortDescription":"Siemens SIRIUS 3RA2120-1KE24-0BB4 direct-on-line motor starter, Size S0, 12 A at 400 V AC-3, 24 V DC control, Class 10, screw and snap-on DIN-rail mount.","salesMarkdown":"## 12 A AC-3 motor switching, 24 V DC coil — panel-fit constraints The 3RA2120-1KE24-0BB4: The control coil is 24 V DC — a common PLC output level — so it drops into a 24 VDC control circuit without an interposing relay. The S0 frame size (45 mm wide, 243 mm tall, 107 mm deep) fits standard 35 mm DIN-rail panels; allow 50 mm above and 20 mm in front for ventilation and wiring access. The assembly ships with the contactor (3RT2024-2BB40) and link module (3RA2921-2AA00) pre-configured; main-circuit connections use spring-loaded terminals for tool-less wiring. ## Motor sizing across voltage ranges At 460/480 V it handles 7.5 hp; at 575/600 V it handles 10 hp — covering the common North American motor voltages in a single starter variant. For 230 V systems, it's rated 3 hp; for 110/120 V, 0.75 hp — useful for retrofit into legacy panels with mixed voltage feeds.","metaTitle":"Siemens 3RA2120-1KE24-0BB4 SIRIUS Direct Starter, 12 A AC-3","metaDescription":"Siemens SIRIUS 3RA2120-1KE24-0BB4 direct-on-line motor starter, 12 A at 400 V AC-3, 24 V DC coil, Class 10, Size S0, DIN-rail mount.","metaKeywords":null},"attributes":{"series":null,"packageCase":null,"mountingType":null,"rohsStatus":null,"productStatus":"Active","categoryPath":["Motor Starters"],"specifications":{"Depth":"107 mm","Width":"45 mm","Height":"243 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":"5 500 kW","at 480 V rated value":"11 A","at 600 V rated value":"10 A","Design Of The Product":"for standard rail or screw mounting","For Main Current Circuit":"spring-loaded terminals","Temperature Compensation":"-20 ... +60 °C","at 110/120 V rated value":"0.75 hp","at 200/208 V rated value":"3 hp","at 220/230 V rated value":"3 hp","at 460/480 V rated value":"7.5 hp","at 575/600 V rated value":"10 hp","Of The Supplied Contactor":"3RT2024-2BB40","Of The Supplied Link Module":"3RA2921-2AA00","Size Of The Circuit-Breaker":"S0","at AC-3 rated value maximum":"690 V","at AC-3 at 400 V rated value":"12 A","at AC-3e rated value maximum":"690 V","Substance Prohibitance (Date)":"03/01/2017","at AC-3e at 400 V rated value":"12 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":"3RV2021-1KA20","degree of protection NEMA rating":"other","For Auxiliary And Control Circuit":"spring-loaded 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":"3.4 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":"163 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":"9 ... 12.5 A"}},"commercial":{"minOrderQty":null,"leadTime":null,"referencePrice":"$106.68","priceTiers":null},"links":{"datasheetUrl":"https://cdn.aoctrl.com/475008114a6e44073244dee31b8f62f4.pdf","sourceUrl":"https://support.industry.siemens.com/webbackend/api/ProductSupport/TechnicalData?language=en&region=cn&productId=10743&mlfb=3RA2120-1KE24-0BB4","alternativesUrl":"https://aoctrl.com/api/mcp/products/3RA2120-1KE24-0BB4/alternatives.json"},"ai":{"faq":[{"question":"What motor sizes does this starter cover at 480 V?","answer":"At 460/480 V it is rated for 7.5 hp; at 575/600 V it is rated for 10 hp. The AC-3 switching current at 400 V is 12 A."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"matrix-langgraph","citationUrl":"https://aoctrl.com/siemens/3RA2120-1KE24-0BB4","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/3RA2120-1KE24-0BB4 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}}