{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"3RA2125-4EH27-0FB4","brand":"Siemens","brandSlug":"siemens","productSlug":"3RA2125-4EH27-0FB4","canonicalUrl":"https://aoctrl.com/siemens/3RA2125-4EH27-0FB4","factsUrl":"https://aoctrl.com/api/mcp/products/3RA2125-4EH27-0FB4","rawCanonicalId":null},"summary":{"shortDescription":"Siemens SIRIUS 3RA2125-4EH27-0FB4 direct-on-line motor starter, Size S0, 15 kW at 400 V AC-3, Class 10, spring-loaded terminals, for 60 mm busbar systems.","salesMarkdown":"## SIRIUS direct starter for 60 mm busbar panels The Siemens 3RA2125-4EH27-0FB4 is a SIRIUS direct-on-line starter in Size S0, designed to snap onto 60 mm busbar systems — a common layout in compact motor control centres where panel space is tight. It delivers 15 kW at 400 V AC-3 (max 690 V) with a Class 10 thermal bimetal overload relay, so it handles standard induction motor starting without nuisance tripping on moderate inertia loads. ## Termination and mounting fit Both main and auxiliary/control circuits use spring-loaded terminals — no screw torque checks, just strip and push for solid or ferruled stranded wire. Mounting is vertical only, with 45 mm width and 165 mm depth, leaving 50 mm clearance above and 20 mm at the sides for airflow and wiring access. ## Active production — sourcing posture We source it against your BOM quantity and confirm lead time and pricing at quote — no minimums beyond the manufacturer's standard MOQ.","metaTitle":"Siemens 3RA2125-4EH27-0FB4 SIRIUS Direct Starter","metaDescription":"Siemens 3RA2125-4EH27-0FB4 SIRIUS direct-on-line starter, 15 kW at 400 V AC-3, Class 10, spring terminals, snaps onto 60 mm busbars.","metaKeywords":null},"attributes":{"series":null,"packageCase":null,"mountingType":null,"rohsStatus":null,"productStatus":"Active","categoryPath":["Motor Starters"],"specifications":{"Depth":"165 mm","Width":"45 mm","title":"3RA2125-4EH27-0FB4","Height":"260 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 27...32 A 24 V DC Spring-type terminal for 60 mm busbar systems (also fulfills type of coordination 1) Type of coordination 2, Iq = 150 kA 1 NO+1 NC (contactor) with diode combination plugged in at the front","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":"2","Product Designation":"Direct (on-line) starter","Size Of Load Feeder":"S0","PROFINET IO protocol":"No","at 400 V rated value":"15 000 W","Design Of The Product":"for 60 mm busbars","For Main Current Circuit":"spring-loaded terminals","Temperature Compensation":"-20 ... +60 °C","Of The Supplied Contactor":"3RT2027-2FB40","Of The Supplied Link Module":"3RA2921-2AA00","Size Of The Circuit-Breaker":"S0","at AC-3 rated value maximum":"690 V","Design Of The Overload Release":"thermal (bimetallic)","Of The Supplied Busbar Adapter":"8US1251-5NT11","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":"3RV2021-4EA25","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 %","Surge Voltage Resistance Rated Value":"6 kV","Number Of Poles For Main Current Circuit":"3","Product Function Short Circuit Protection":"Yes","protocol is supported AS-Interface protocol":"No","number of NC contacts for auxiliary contacts":"1","number of NO contacts for auxiliary contacts":"1","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","operational current at AC-3 at 400 V rated value":"29 A","Mechanical Service Life (Switching Cycles) Of Contactor Typical":"10 000 000","insulation voltage with degree of pollution 3 at AC rated value":"690 V","Adjustable Current Response Value Current Of The Current-Dependent Overload Release":"27 ... 32 A"}},"commercial":{"minOrderQty":null,"leadTime":null,"referencePrice":null,"stockQuantity":0,"priceTiers":null},"links":{"datasheetUrl":"https://cdn.aoctrl.com/de7d3e0d462a0e3463c5358c0a7f263b.pdf","sourceUrl":"https://support.industry.siemens.com/webbackend/api/ProductSupport/TechnicalData?language=en&region=cn&productId=553539&mlfb=3RA2125-4EH27-0FB4"},"ai":{"faq":[{"question":"Where can I buy the 3RA2125-4EH27-0FB4 and get a price?","answer":"We source this starter to order against your BOM — send an RFQ and we will confirm availability and current pricing from authorized distribution."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"icboms-matrix-langgraph","citationUrl":"https://aoctrl.com/siemens/3RA2125-4EH27-0FB4","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/3RA2125-4EH27-0FB4 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}}