{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"3RT2045-1KB44-3MA0","brand":"Siemens","brandSlug":"siemens","productSlug":"3RT2045-1KB44-3MA0","canonicalUrl":"https://aoctrl.com/siemens/3RT2045-1KB44-3MA0","factsUrl":"https://aoctrl.com/api/mcp/products/3RT2045-1KB44-3MA0","rawCanonicalId":null},"summary":{"shortDescription":"Siemens SIRIUS coupling contactor, size S3, 24 V DC coil, screw-type terminals, auxiliary switch, 195 x 140 x 70 mm.","salesMarkdown":"The Siemens 3RT2045-1KB44-3MA0 is a SIRIUS coupling contactor, size S3, designed to switch loads in control panels where a galvanically isolated interface between control and power circuits is required. It mounts on a 35 mm DIN rail per DIN EN 60715 via screw or snap-on fastening, and its mounting position allows ±180° rotation on a vertical surface plus ±22.5° tilt forward/backward — useful when panel layout forces an unconventional orientation. Rated control supply voltage is 24 V DC. The coil operates between 0.8 and 1.2 times the rated value (19.2 to 28.8 V DC), with an inrush current peak of 2.7 A and a holding current of 6 A at 24 V. Dropout delay on DC is 38 to 57 ms — enough to ride through brief dips but fast enough for most safety circuits. Arcing time runs 10 to 20 ms, so factor that into your contactor sequencing logic. ## Load switching capability Switching frequency varies by duty: 900 operations per hour at AC-1 (resistive), 400/h at AC-2 (slip-ring motors), 1000/h at AC-3 (squirrel-cage motors), 300/h at AC-4 (plugging/inching), and 1000/h at AC-3e (enhanced AC-3). The auxiliary switch is present, with screw-type terminals on the coil and main contacts accepting solid conductors from 2.5 to 16 mm² and stranded from 6 to 70 mm². Auxiliary contact terminals accept 2x (0.5 to 1.5 mm²) solid or 2x (0.75 to 2.5 mm²) stranded. Shock resistance is 16.3 g / 5 ms (half-sine) and 10 g / 10 ms.","metaTitle":"Siemens 3RT2045-1KB44-3MA0 SIRIUS Coupling Contactor, 24 VDC","metaDescription":"Siemens SIRIUS coupling contactor 3RT2045-1KB44-3MA0, size S3, 24 VDC coil, screw terminals. Active production. Sourced to order against RFQ.","metaKeywords":null},"attributes":{"series":null,"packageCase":null,"mountingType":null,"rohsStatus":null,"productStatus":"Active","categoryPath":["Contactors"],"specifications":{"Depth":"195 mm","Solid":"2.5 ... 16 mm²","Width":"70 mm","at AC":"16.3g / 5 ms, 10.g / 10 ms","at DC":"38 ... 57 ms","title":"3RT2045-1KB44-3MA0","Height":"140 mm","Upwards":"10 mm","Forwards":"20 mm","Stranded":"6 ... 70 mm²","Downwards":"10 mm","Arcing Time":"10 ... 20 ms","At The Side":"10 mm","Rated Value":"24 V","description":"power contactor, AC-3e/AC-3, 80 A, 37 kW / 400 V, 3-pole, 24 V DC, 0.8-1.2* Us, with integrated varistor, auxiliary contacts: 1 NO + 1 NC, screw terminal, size: S3, suitable for PLC outputs, captive auxiliary switch","Initial Value":"0.8","During Storage":"-55 ... +80 °C","Of Magnet Coil":"Screw-type terminals","at AC-1 maximum":"900 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","Auxiliary Switch":"Yes","During Operation":"-25 ... +60 °C","Fastening Method":"screw and snap-on mounting onto 35 mm DIN rail according to DIN EN 60715","Full-Scale Value":"1.2","at AC-3e maximum":"1 000 1/h","For Main Contacts":"10 ... 2","Mounting Position":"+/-180° rotation possible on vertical mounting surface; can be tilted forward and backward by +/- 22.5° on vertical mounting surface","Size Of Contactor":"S3","Solid Or Stranded":"2x (0.5 ... 1.5 mm²), 2x (0.75 ... 2.5 mm²)","Product Brand Name":"SIRIUS","Inrush Current Peak":"2.7 A","Product Designation":"Coupling contactor","at 24 V rated value":"6 A","at 48 V rated value":"2 A","at 60 V rated value":"2 A","Of Contactor Typical":"10 000 000","at 110 V rated value":"1 A","at 125 V rated value":"0.9 A","at 220 V rated value":"0.3 A","at 230 V rated value":"15 hp","at 400 V rated value":"3 A","at 440 V rated value":"0.8 A","at 480 V rated value":"77 A","at 500 V rated value":"2 A","at 600 V rated value":"62 A","at 690 V rated value":"1 A","Side-By-Side Mounting":"Yes","at 1000 V rated value":"37 kW","For Auxiliary Contacts":"20 ... 14","For Main Current Circuit":"screw-type terminals","at 110/120 V rated value":"7.5 hp","at 200/208 V rated value":"25 hp","at 220/230 V rated value":"30 hp","at 460/480 V rated value":"60 hp","at 575/600 V rated value":"60 hp","Locked-Rotor Current Peak":"2.1 A","Relative Humidity Minimum":"10 %","Holding Current Mean Value":"40 mA","Of Main Circuit Rated Value":"8 kV","Safety-Related Switching On":"No","at AC-3 rated value maximum":"1 000 V","at AC in hot operating state":"15.9 W","at AC-2 at 400 V rated value":"37 kW","at AC-3e rated value maximum":"1 000 V","at AC-4 at 400 V rated value":"66 A","safety-related switching OFF":"Yes","Substance Prohibitance (Date)":"03/01/2017","Design Of The Surge Suppressor":"with varistor","Duration Of Inrush Current Peak":"50 µs","Locked-Rotor Current Mean Value":"0.9 A","Duration Of Locked-Rotor Current":"150 ms","Of Auxiliary Circuit Rated Value":"6 kV","at AC-5a up to 690 V rated value":"110 A","at AC-5b up to 400 V rated value":"80 A","For Auxiliary And Control Circuit":"screw-type terminals","Function Module For Communication":"No","With Type Of Assignment 2 Required":"gG: 160A (690V,100kA), aM: 80A (690V,100kA), BS88: 125A (415V,80kA)","Without Load Current Share Typical":"0.9 W","closing power of magnet coil at DC":"25 W","holding power of magnet coil at DC":"0.9 W","At Contactor For Auxiliary Contacts":"Screw-type terminals","With Type Of Coordination 1 Required":"gG: 250 A (690 V, 100 kA), aM: 160 A (690 V, 100 kA), BS88: 200 A (415 V, 80 kA)","operational current at AC-12 maximum":"10 A","at AC in hot operating state per pole":"5.3 W","for AWG cables for auxiliary contacts":"2x (20 ... 16), 2x (18 ... 14)","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","Contact Reliability Of Auxiliary Contacts":"1 faulty switching per 100 million (17 V, 1 mA)","mirror contact according to IEC 60947-4-1":"Yes","with low demand rate according to SN 31920":"40 %","with high demand rate according to SN 31920":"73 %","Type Of Voltage Of The Control Supply Voltage":"DC","Limited To 1 S Switching At Zero Current Maximum":"1 500 A; Use minimum cross-section acc. to AC-1 rated value","Limited To 5 S Switching At Zero Current Maximum":"1 186 A; Use minimum cross-section acc. to AC-1 rated value","Limited To 10 S Switching At Zero Current Maximum":"851 A; Use minimum cross-section acc. to AC-1 rated value","Limited To 30 S Switching At Zero Current Maximum":"538 A; Use minimum cross-section acc. to AC-1 rated value","Limited To 60 S Switching At Zero Current Maximum":"423 A; Use minimum cross-section acc. to AC-1 rated value","contact rating of auxiliary contacts according to UL":"A600 / P600","Of Main Circuit With Degree Of Pollution 3 Rated Value":"1 000 V","Installation Altitude At Height Above Sea Level Maximum":"2 000 m","Of The Contactor With Added Auxiliary Switch Block Typical":"10 000 000","Of Auxiliary Circuit With Degree Of Pollution 3 Rated Value":"690 V","For Short-Circuit Protection Of The Auxiliary Switch Required":"gG: 10 A (500 V, 1 kA)","minimum cross-section in main circuit at maximum AC-1 rated value":"50 mm²","number of NC contacts for auxiliary contacts instantaneous contact":"2","number of NO contacts for auxiliary contacts instantaneous contact":"2","Of The Contactor With Added Electronically Optimized Auxiliary Switch Block Typical":"5 000 000"}},"commercial":{"minOrderQty":null,"leadTime":null,"referencePrice":"$201.93","stockQuantity":0,"priceTiers":null},"links":{"datasheetUrl":"https://cdn.aoctrl.com/7d28fa7380658c541019ac8751bc4da6.pdf","sourceUrl":"https://support.industry.siemens.com/webbackend/api/ProductSupport/TechnicalData?language=en&region=cn&productId=629801&mlfb=3RT2045-1KB44-3MA0"},"ai":{"faq":[{"question":"Is 3RT2045-1KB44-3MA0 available via RFQ confirmation and what is the lead time?","answer":"Availability and current pricing are confirmed at quote time against an RFQ; the part is sourced to order through independent distribution."},{"question":"What is the closest functional second-source for 3RT2045-1KB44-3MA0?","answer":"The peer 3RT1264-6AP36-0KA1 is a different size and a standard power contactor, not a coupling contactor — physical fit and terminal layout differ; verify footprint before substituting."},{"question":"What is 3RT2045-1KB44-3MA0's listed depth?","answer":"The depth is 195 mm."},{"question":"What solid conductor cross-section does 3RT2045-1KB44-3MA0 accept?","answer":"Solid conductors from 2.5 to 16 mm²."},{"question":"What compliance documentation does Siemens provide for this contactor?","answer":"The evidence does not list specific compliance documents, but as a SIRIUS product it typically carries CE, UL, and CSA markings — confirm with the order documentation at time of purchase."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"icboms-matrix-langgraph","citationUrl":"https://aoctrl.com/siemens/3RT2045-1KB44-3MA0","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/3RT2045-1KB44-3MA0 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}}