{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"3RT1044-1XB40-0LA2","brand":"Siemens","brandSlug":"siemens","productSlug":"3RT1044-1XB40-0LA2","canonicalUrl":"https://aoctrl.com/siemens/3RT1044-1XB40-0LA2","factsUrl":"https://aoctrl.com/api/mcp/products/3RT1044-1XB40-0LA2","rawCanonicalId":null},"summary":{"shortDescription":"Siemens SIRIUS power contactor, size S3, 3RT1044-1XB40-0LA2, screw-type terminals, 24 VDC coil, rated 37 kW at 500 V AC-3, 18.6 kW at 690 V AC-3.","salesMarkdown":"## SIRIUS S3 Power Contactor for Motor Loads Its AC-3 rating of 37 kW at 500 V and 18.6 kW at 690 V defines the motor load it can handle under typical starting and running conditions — the rating that governs real-world sizing, not the higher AC-1 resistive figure. The 24 VDC coil with a pick-up threshold of 0.7x rated value (about 16.8 V) and dropout below that ensures reliable pull-in even on a sagging control supply. Side-by-side mounting is permitted, so multiple contactors can be ganged without spacing blocks. The envelope is 176 mm high by 70 mm wide by 152 mm deep. Main circuit terminals are screw-type, accepting a wide range of conductor sizes: solid or stranded 2x (0.5 to 1.5 mm²), 2x (0.75 to 2.5 mm²), and up to 2x (0.75 to 4 mm²) for control wiring. The main power terminals accept 2x (10 to 50 mm²) stranded, with a maximum of 35 mm² for AC-1 rated connections. This range covers most panel wiring from control-circuit signal wires up to motor feeder cables.","metaTitle":"Siemens 3RT1044-1XB40-0LA2 SIRIUS Power Contactor, S3, 37 kW","metaDescription":"Siemens 3RT1044-1XB40-0LA2 SIRIUS power contactor, size S3, rated 37 kW at 500 V AC-3. Screw terminals, 24 VDC coil. Active lifecycle, available to order. Quoted on request.","metaKeywords":null},"attributes":{"series":null,"packageCase":null,"mountingType":null,"rohsStatus":null,"productStatus":null,"categoryPath":["Contactors"],"specifications":{"Depth":"152 mm","Solid":"2x (0.5 ... 1.5 mm²), 2x (0.75 ... 2.5 mm²), max. 2x (0.75 ... 4 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":"24 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 standard mounting 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","at AWG cables for main contacts":"2x (10 ... 1/0)","For Auxiliary And Control Circuit":"screw-type 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 (20 ... 16), 2x (18 ... 14), 1x 12","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 (0.5 ... 1.5 mm²), 2x (0.75 ... 2.5 mm²)","Number Of Poles For Main Current Circuit":"3","Finely Stranded Without Core End Processing":"2x (10 ... 35 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=161781&mlfb=3RT1044-1XB40-0LA2","alternativesUrl":"https://aoctrl.com/api/mcp/products/3RT1044-1XB40-0LA2/alternatives.json"},"ai":{"faq":[{"question":"What is the closest functional alternative to 3RT1044-1XB40-0LA2?","answer":"The 3RT1044-1FB46 is a peer in the same S3 frame size but with a different coil voltage — 110 VAC/DC versus the 24 VDC coil on the -1XB40-0LA2. Panel fit and wiring footprint are identical; the choice is purely control-voltage driven."},{"question":"Where can I buy 3RT1044-1XB40-0LA2 and how is it quoted?","answer":"This part is sourced through independent industrial-automation distribution and quoted to order against an RFQ. Submit a request with your quantity and target delivery date for current pricing and availability."},{"question":"What are the key motor power ratings for this contactor?","answer":"Rated 37 kW at 500 V AC-3 and 18.6 kW at 690 V AC-3 — these are the motor-load ratings that determine real-world sizing."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"matrix-langgraph","citationUrl":"https://aoctrl.com/siemens/3RT1044-1XB40-0LA2","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/3RT1044-1XB40-0LA2 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}}