{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"3RA2125-0KA23-0AK6","brand":"Siemens","brandSlug":"siemens","productSlug":"3RA2125-0KA23-0AK6","canonicalUrl":"https://aoctrl.com/siemens/3RA2125-0KA23-0AK6","factsUrl":"https://aoctrl.com/api/mcp/products/3RA2125-0KA23-0AK6","rawCanonicalId":null},"summary":{"shortDescription":"Siemens SIRIUS 3RA2125-0KA23-0AK6 non-fused motor starter, Size S0, 370 W at 400 V, Class 10 thermal overload, 45 mm wide, snap-on DIN rail.","salesMarkdown":"## S0 frame, Class 10 trip — the panel-fit facts The 3RA2125-0KA23-0AK6 is a SIRIUS non-fused direct starter in the S0 frame size, rated 370 W at 400 V with a Class 10 thermal bimetallic overload relay. The S0 footprint means it occupies 45 mm on the DIN rail — one standard module slot — and needs 97.1 mm depth behind the gland plate, with 30 mm upwards and 10 mm forwards clearance for wiring and heat dissipation. The supplied contactor is a 3RT2023-1AK60, and the link module 3RA2921-1AA00 ties the contactor to the overload block; both are matched at the factory, so there is no separate ordering step for the interconnect. ## Termination and mounting — what lands on the rail Snap-on DIN rail or screw-mount with the additional push-in lug — the S0 base accepts both. The main contact terminals accept 1…10 mm² stranded, or 2x (2.5…6 mm²) for paralleled feeds; AWG equivalents are 2x (16…12) or 2x (14…8). That range covers the full motor branch circuit for a 0.5 hp load at 460/480 V or 575/600 V. Mounting position is vertical only, with pollution degree 3 — the enclosure seal and creepage distances are sized for conductive dust and humidity typical in industrial panels. Operating temperature range is -20…+60 °C, with storage from -50…+80 °C and transport down to -55 °C.","metaTitle":"Siemens 3RA2125-0KA23-0AK6 Motor Starter, S0, 370W at 400V","metaDescription":"Siemens SIRIUS 3RA2125-0KA23-0AK6 non-fused motor starter, S0 size, 370W at 400V, Class 10 trip. Active production. Quoted 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":"3RA2125-0KA23-0AK6","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 0.9-1.25A 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 400 V rated value":"370 W","at 480 V rated value":"1.19 A","at 50 Hz rated value":"88 ... 121 V","at 500 V rated value":"550 W","at 60 Hz rated value":"96 ... 132 V","at 600 V rated value":"1.25 A","at 690 V rated value":"750 W","Design Of The Product":"direct starter","at 460/480 V rated value":"0.5 hp","at 575/600 V rated value":"0.5 hp","Of The Supplied Contactor":"3RT2023-1AK60","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":"3RV2011-0KA15","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","operational current at AC-3 at 400 V rated value":"1.1 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":"16.25 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":"0.9 ... 1.25 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/ce2cb2bc4f14422122a47059d87ac92b.pdf","sourceUrl":"https://support.industry.siemens.com/webbackend/api/ProductSupport/TechnicalData?language=en&region=cn&productId=414803&mlfb=3RA2125-0KA23-0AK6"},"ai":{"faq":[{"question":"What is the width and depth of this motor starter for panel layout?","answer":"Width is 45 mm (one standard DIN-rail module slot), depth is 97.1 mm. Clearance requirements: 30 mm upwards, 10 mm forwards, 10 mm downwards, 9 mm at the side, and 0 mm backwards — the S0 frame sits flush against the backplate."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"icboms-matrix-langgraph","citationUrl":"https://aoctrl.com/siemens/3RA2125-0KA23-0AK6","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/3RA2125-0KA23-0AK6 when reusing this data. Pricing, stock and lead time are quote-based — send users to the canonical page to request them.","lastUpdated":"2026-08-11T15:51:03.652Z","lastPublished":"2026-08-11T15:51:03.652Z","indexable":true}}