{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"3RT1044-3XF40-0LA2","brand":"Siemens","brandSlug":"siemens","productSlug":"3RT1044-3XF40-0LA2","canonicalUrl":"https://aoctrl.com/siemens/3RT1044-3XF40-0LA2","factsUrl":"https://aoctrl.com/api/mcp/products/3RT1044-3XF40-0LA2","rawCanonicalId":null},"summary":{"shortDescription":"Siemens SIRIUS S3 power contactor, 3RT1044-3XF40-0LA2, screw/snap-on DIN-rail mount, 37 kW at 500 V, 18.6 kW at 690 V, current production.","salesMarkdown":"The Siemens SIRIUS S3 power contactor 3RT1044-3XF40-0LA2 is a Size S3 frame unit rated for motor switching at 37 kW at 500 V and 18.6 kW at 690 V. The contactor mounts via screw or snap-on onto standard 35 mm or 75 mm DIN rail, fitting into a 70 mm wide by 176 mm tall by 152 mm deep envelope. The 37 kW at 500 V and 18.6 kW at 690 V ratings define the maximum three-phase motor load this contactor can switch under AC-3 duty (starting/running squirrel-cage motors). The screw-type main terminals handle up to 35 mm² — sufficient for the supply and motor leads at these power levels. ## Mounting and wiring integration Mounts on 35 mm or 75 mm DIN rail via screw or snap-on fastening. Side-by-side mounting is permitted. Control circuit wiring accepts 2x (0.25 to 2.5 mm²) solid or stranded conductors; main circuit terminals accept 2x (10 to 50 mm²) stranded.","metaTitle":"Siemens 3RT1044-3XF40-0LA2 SIRIUS S3 Power Contactor, 37 kW","metaDescription":"Siemens SIRIUS S3 power contactor 3RT1044-3XF40-0LA2, rated 37 kW at 500 V and 18.6 kW at 690 V. Screw/snap-on DIN-rail mount, current production. Quoted to order.","metaKeywords":null},"attributes":{"series":null,"packageCase":null,"mountingType":null,"rohsStatus":null,"productStatus":null,"categoryPath":["Contactors"],"specifications":{"Depth":"152 mm","Solid":"2x (0.25 ... 2.5 mm²)","Width":"70 mm","at DC":"14 ... 20 ms","Height":"176 mm","Upwards":"10 mm","Forwards":"20 mm","Stranded":"2x (10 ... 50 mm²)","Downwards":"10 mm","Arcing Time":"10 ... 15 ms","At The Side":"10 mm","Rated Value":"110 V","Initial Value":"0.7","During Storage":"-55 ... +80 °C","at AC-1 maximum":"1 000 1/h","at AC-2 maximum":"400 1/h","at AC-3 maximum":"1 000 1/h","at AC-4 maximum":"300 1/h","lifecycle_stage":"current","During Operation":"-40 ... +70 °C","Fastening Method":"screw and snap-on mounting onto 35 mm and 75 mm DIN rail","Full-Scale Value":"1.25","Size Of Contactor":"S3","Solid Or Stranded":"2x (2.5 ... 16 mm²)","Product Brand Name":"SIRIUS","Product Designation":"Power contactor","at 24 V rated value":"10 A","at 60 V rated value":"2 A","Of Contactor Typical":"10 000 000","at 110 V rated value":"1 A","at 220 V rated value":"0.3 A","at 230 V rated value":"6 A","at 400 V rated value":"3 A","at 500 V rated value":"37 kW","at 690 V rated value":"18.6 kW","Instantaneous Contact":"0","Side-By-Side Mounting":"Yes","at 1000 V rated value":"30 W","For Main Current Circuit":"screw-type terminals","at maximum AC-1 rated value":"35 mm²","at AC-2 at 400 V rated value":"30 kW","at AC-4 at 400 V rated value":"55 A","Substance Prohibitance (Date)":"05/01/2012","Design Of The Surge Suppressor":"with varistor","For Auxiliary And Control Circuit":"spring-loaded terminals","Function Module For Communication":"No","With Type Of Assignment 2 Required":"fuse gL/gG: 125 A","closing power of magnet coil at DC":"19 W","holding power of magnet coil at DC":"12 W","With Type Of Coordination 1 Required":"fuse gL/gG: 250 A","at AWG cables for auxiliary contacts":"2x (24 ... 14)","operational current at AC-12 maximum":"10 A","number of NC contacts for main contacts":"0","number of NO contacts for main contacts":"3","reference code according to IEC 81346-2":"Q","Finely Stranded With Core End Processing":"2x (0.25 ... 1.5 mm²)","Number Of Poles For Main Current Circuit":"3","Finely Stranded Without Core End Processing":"2x (0.25 ... 2.5 mm²)","Type Of Voltage Of The Control Supply Voltage":"DC","contact rating of auxiliary contacts according to UL":"A600 / Q600","Installation Altitude At Height Above Sea Level Maximum":"2 000 m","Of The Contactor With Added Auxiliary Switch Block Typical":"10 000 000","For Short-Circuit Protection Of The Auxiliary Switch Required":"fuse gL/gG: 10 A","Of The Contactor With Added Electronically Optimized Auxiliary Switch Block Typical":"5 000 000"}},"commercial":{"minOrderQty":null,"leadTime":null,"referencePrice":null,"priceTiers":null},"links":{"datasheetUrl":null,"sourceUrl":"https://support.industry.siemens.com/webbackend/api/ProductSupport/TechnicalData?language=en&region=cn&productId=291468&mlfb=3RT1044-3XF40-0LA2","alternativesUrl":"https://aoctrl.com/api/mcp/products/3RT1044-3XF40-0LA2/alternatives.json"},"ai":{"faq":[{"question":"Where can I buy 3RT1044-3XF40-0LA2 and get a price?","answer":"This part is sourced and quoted to order against an RFQ through independent distribution. Availability and current pricing are confirmed at quote time — submit an RFQ for a firm quote."},{"question":"What is the closest functional second-source for 3RT1044-3XF40-0LA2?","answer":"The peer 3RT1044-1FB46 is a functionally similar SIRIUS S3 contactor but differs in coil voltage and auxiliary contact configuration — verify coil compatibility before substituting."},{"question":"What are the physical dimensions of 3RT1044-3XF40-0LA2?","answer":"The contactor measures 70 mm wide, 176 mm tall, and 152 mm deep, fitting a standard S3 frame footprint on 35 mm or 75 mm DIN rail."},{"question":"Will 3RT1044-3XF40-0LA2 drop into a panel specified for 3RT1044-1FB46 without rewiring?","answer":"Both are S3 frame size with the same 70 mm width and DIN-rail mount, so the mechanical fit is identical. However, verify the coil voltage and auxiliary contact arrangement — the 3XF40 variant carries different control circuit ratings that may require terminal re-assignment."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"matrix-langgraph","citationUrl":"https://aoctrl.com/siemens/3RT1044-3XF40-0LA2","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/3RT1044-3XF40-0LA2 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}}