{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"3RA2120-1GE24-0BB4","brand":"Siemens","brandSlug":"siemens","productSlug":"3RA2120-1GE24-0BB4","canonicalUrl":"https://aoctrl.com/siemens/3RA2120-1GE24-0BB4","factsUrl":"https://aoctrl.com/api/mcp/products/3RA2120-1GE24-0BB4","rawCanonicalId":null},"summary":{"shortDescription":"Siemens SIRIUS 3RA2120-1GE24-0BB4 direct online starter, S0 size, 6.3 A AC-3 at 400 V, 24 VDC coil, Class 10 trip, screw and snap-on DIN rail mounting, spring-loaded terminals.","salesMarkdown":"## What this direct starter delivers in a dusty panel The 3RA2120-1GE24-0BB4: The 24 VDC coil keeps the control circuit low-voltage, which matters when your panel runs on a 24 VDC bus and you want to avoid pulling a separate AC control transformer. The S0 feeder size and the included contactor (3RT2024-2BB40) and link module (3RA2921-2AA00) mean you get a matched set, not a field-assembled guess. ## Mounting and wiring in a tight enclosure Vertical mounting position only; the 20 mm forward clearance and 50 mm upward clearance keep airflow for the thermal overload. Spring-loaded terminals on the main current circuit mean no screw torque to forget — strip the wire, push it in, done. That saves time on a multi-starter panel and eliminates the risk of a loose connection vibrating open near a kiln or conveyor drive. ## Survives the heat and grit of an industrial floor Storage and transport range is -50 °C to +80 °C, so it can sit in a hot warehouse or truck without damage. The S0 breaker size and the Class 10 trip curve are coordinated with the supplied contactor — no separate fuse sizing exercise. For a 5 hp motor at 460/480 V or a 2 hp at 220/230 V, this starter is a single order code that covers the whole motor branch circuit.","metaTitle":"Siemens 3RA2120-1GE24-0BB4 SIRIUS Direct Starter, 6.3 A AC-3","metaDescription":"Siemens 3RA2120-1GE24-0BB4 SIRIUS direct online starter, 6.3 A at 400 V AC-3, 24 VDC coil, Class 10, S0 size, screw/snap-on DIN rail.","metaKeywords":null},"attributes":{"series":null,"packageCase":null,"mountingType":null,"rohsStatus":null,"productStatus":"Active","categoryPath":["Motor Starters"],"specifications":{"Depth":"107 mm","Width":"45 mm","title":"3RA2120-1GE24-0BB4","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","description":"Load feeder fuseless, Direct-on-line starting 400 V AC, Size S0 4.50...6.30 A 24 V DC Spring-type 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":"0.75 hp","at 400 V rated value":"2 200 kW","at 480 V rated value":"6.3 A","at 600 V rated value":"6.3 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":"0.25 hp","at 200/208 V rated value":"2 hp","at 220/230 V rated value":"2 hp","at 460/480 V rated value":"5 hp","at 575/600 V rated value":"5 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":"6.3 A","at AC-3e rated value maximum":"690 V","Substance Prohibitance (Date)":"03/01/2017","at AC-3e at 400 V rated value":"6.3 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":"3RV2021-1GA20","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":"2.7 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":"82 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":"4.5 ... 6.3 A"}},"commercial":{"minOrderQty":null,"leadTime":null,"referencePrice":null,"stockQuantity":0,"priceTiers":null},"links":{"datasheetUrl":"https://cdn.aoctrl.com/128e7a41a24f12f833bc6dbf192f5f5a.pdf","sourceUrl":"https://support.industry.siemens.com/webbackend/api/ProductSupport/TechnicalData?language=en&region=cn&productId=181199&mlfb=3RA2120-1GE24-0BB4"},"ai":{"faq":[{"question":"Where can I buy 3RA2120-1GE24-0BB4 and get a price?","answer":"We source this part through independent distribution. Submit an RFQ with your target quantity; we confirm availability and current pricing at quote time. No stock-holding claim — each order is quoted against the BOM."},{"question":"What is the AC-3 rating at 400 V for this starter?","answer":"That is the motor-switching current — the value you use for sizing the starter to the motor full-load current, not the thermal overload setting."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"icboms-matrix-langgraph","citationUrl":"https://aoctrl.com/siemens/3RA2120-1GE24-0BB4","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/3RA2120-1GE24-0BB4 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}}