{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"3RA2125-1FA24-0AK6","brand":"Siemens","brandSlug":"siemens","productSlug":"3RA2125-1FA24-0AK6","canonicalUrl":"https://aoctrl.com/siemens/3RA2125-1FA24-0AK6","factsUrl":"https://aoctrl.com/api/mcp/products/3RA2125-1FA24-0AK6","rawCanonicalId":null},"summary":{"shortDescription":"Siemens SIRIUS 3RA2125-1FA24-0AK6 non-fused motor starter, S0 size, CLASS 10 thermal bimetallic overload, 690 V AC-3, direct starter, snap-on DIN rail mount.","salesMarkdown":"## S0 direct starter for motor branch circuits The Siemens 3RA2125-1FA24-0AK6 is a SIRIUS non-fused motor starter in the S0 frame size, combining a contactor and a thermal bimetallic overload relay in one assembly. It is configured as a direct starter, meaning it connects the motor directly across the line without reduced-voltage starting — the simplest and most common starting method for fixed-speed pumps, fans, and conveyors up to about 3 hp at 460/480 V. This is the standard trip class for general-purpose induction motors that accelerate to full speed in under 10 seconds — if the motor has a high-inertia load (centrifuge, large fan), a CLASS 20 or CLASS 30 overload might be needed, but for most pump and compressor duty this is the correct fit. Rated for AC-3 switching duty up to 690 V, the starter handles the inrush and breaking of squirrel-cage motors within its power band. At 400 V it delivers 1 500 W (about 2 hp), and at 500 V it delivers 2 200 W (about 3 hp). The thermal overload uses a bimetallic element — no electronics to fail, but ambient temperature compensation is built into the design. ## Panel fit and clearance envelope Mounting position is vertical — horizontal mounting would require a derating check against the operating temperature range of -20 to +60 °C. Dimensions are 45 mm wide, 193.1 mm high, and 97.1 mm deep — the S0 footprint is taller than the S00 size, so check the backpanel layout before committing. Clearance requirements: 30 mm upwards, 10 mm forwards, 10 mm downwards, 9 mm at the side, and 0 mm backwards. The zero backward clearance means it can sit flush against a mounting plate or busbar support without additional air gap. The supplied contactor is a 3RT2024-1AK60, and the link module is a 3RA2921-1AA00 — these are the factory-matched components inside the starter assembly. If either fails in the field, the entire starter is replaced as a unit rather than swapping individual contactor or overload parts. ## Current production — sourcing posture For volume or project pricing, submit an RFQ with the target quantity and delivery window.","metaTitle":"Siemens 3RA2125-1FA24-0AK6 SIRIUS Motor Starter, S0 Size","metaDescription":"Siemens 3RA2125-1FA24-0AK6 SIRIUS non-fused motor starter, S0 size, CLASS 10 thermal overload, 690 V max AC-3. Sourced to order against RFQ.","metaKeywords":null},"attributes":{"series":null,"packageCase":null,"mountingType":null,"rohsStatus":null,"productStatus":null,"categoryPath":["Motor Starters"],"specifications":{"Depth":"97.1 mm","Width":"45 mm","title":"3RA2125-1FA24-0AK6","Height":"193.1 mm","Upwards":"30 mm","Forwards":"10 mm","Backwards":"0 mm","Downwards":"10 mm","Trip Class":"CLASS 10","At The Side":"9 mm","Rated Value":"690 V","description":"Fuseless motor starter Direct start 600VAC Size S0 3.5-5A 110/120VAC 50/60HZ screw connection For screw mounting Or 35 mm rail-mounting Type of coordination 2 IQ = 150 KA Also full fills type Of coordination 1 1NO+1NC (MSP) 1NO+1NC (contactor)","During Storage":"-50 ... +80 °C","lifecycle_stage":"current","During Operation":"-20 ... +60 °C","During Transport":"-55 ... +80 °C","Fastening Method":"Snap-mounted to DIN rail or screw-mounted with additional push-in lug","Mounting Position":"vertical","Product Brand Name":"SIRIUS","Type Of Assignment":"2","Degree Of Pollution":"3","Product Designation":"non-fused motor starter 3RA2","Size Of Load Feeder":"S0","at 230 V rated value":"0.5 hp","at 400 V rated value":"1 500 W","at 480 V rated value":"4.8 A","at 50 Hz rated value":"88 ... 121 V","at 500 V rated value":"2 200 W","at 60 Hz rated value":"96 ... 132 V","at 600 V rated value":"4.55 A","Design Of The Product":"direct starter","at 110/120 V rated value":"0.17 hp","at 200/208 V rated value":"1 hp","at 220/230 V rated value":"1 hp","at 460/480 V rated value":"3 hp","at 575/600 V rated value":"3 hp","Of The Supplied Contactor":"3RT2024-1AK60","For Main Contacts Stranded":"1 ... 10 mm², 2x (2.5 ... 6 mm²)","Of The Supplied Link Module":"3RA2921-1AA00","Size Of The Circuit-Breaker":"S00","at AC-3 rated value maximum":"690 V","Design Of The Overload Release":"thermal (bimetallic)","Design Of The Switching Contact":"electromechanical","Operating Frequency Rated Value":"50 ... 60 Hz","at AWG cables for main contacts":"2x (16 ... 12), 2x (14 ... 8)","Design Of The Short-Circuit Trip":"magnetic","Of The Supplied Circuit-Breakers":"3RV2011-1FA15","Product Extension Auxiliary Switch":"Yes","Surge Voltage Resistance Rated Value":"6 kV","Number Of Poles For Main Current Circuit":"3","Product Function Short Circuit Protection":"Yes","apparent holding power of magnet coil at AC":"7.2 VA","number of NC contacts for auxiliary contacts":"2","number of NO contacts for auxiliary contacts":"2","shock resistance according to IEC 60068-2-27":"6g / 11 ms","at 400 V according to IEC 60947-4-1 rated value":"153 000 A","at 500 V according to IEC 60947-4-1 rated value":"100 000 A","operational current at AC-3 at 400 V rated value":"3.6 A","Type Of Electrical Connection For Main Current Circuit":"screw-type terminals","Inductive Power Factor With The Holding Power Of The Coil":"0.28","Mechanical Service Life (Switching Cycles) Of Contactor Typical":"10 000 000","Response Value Current Of Instantaneous Short-Circuit Trip Unit":"65 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":"3.5 ... 5 A","Connectable Conductor Cross-Section For Main Contacts Finely Stranded With Core End Processing":"1 ... 6 mm²"}},"commercial":{"minOrderQty":null,"leadTime":null,"referencePrice":null,"stockQuantity":0,"priceTiers":null},"links":{"datasheetUrl":"https://cdn.aoctrl.com/d46a27161342f5cd75ada81a79e7536c.pdf","sourceUrl":"https://support.industry.siemens.com/webbackend/api/ProductSupport/TechnicalData?language=en&region=cn&productId=267292&mlfb=3RA2125-1FA24-0AK6"},"ai":{"faq":[],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"icboms-matrix-langgraph","citationUrl":"https://aoctrl.com/siemens/3RA2125-1FA24-0AK6","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/3RA2125-1FA24-0AK6 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}}