{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"3RT1045-1BB44","brand":"Siemens","brandSlug":"siemens","productSlug":"3RT1045-1BB44","canonicalUrl":"https://aoctrl.com/siemens/3RT1045-1BB44","factsUrl":"https://aoctrl.com/api/mcp/products/3RT1045-1BB44","rawCanonicalId":null},"summary":{"shortDescription":"Siemens SIRIUS 3RT1045-1BB44, size S3 power contactor, 24 VDC coil, screw-type terminals, 45 kW at 500 V, 70 x 146 x 201 mm.","salesMarkdown":"The Siemens 3RT1045-1BB44 is a SIRIUS power contactor in frame size S3, rated for motor switching up to 45 kW at 500 V and 21.1 kW at 690 V. The 24 VDC coil pulls in at 0.8x rated voltage and drops out at 1.1x, with a pick-up delay of 14 to 20 ms and arcing time of 10 to 15 ms — numbers that matter when coordinating control logic timing in a safety circuit or sequence interlock. Screw-type terminals on the main circuit accept solid conductors up to 2x (0.5 to 1.5 mm²) or 2x (0.75 to 2.5 mm²), and stranded up to 2x (10 to 50 mm²). The control circuit terminals handle 2x (2.5 to 16 mm²) solid or stranded. Side-by-side mounting is permitted. Dimensions are 70 mm wide, 146 mm tall, 201 mm deep — the depth is the dimension that often catches panel layouts designed around smaller frames. Verify the 201 mm projection from the rail before committing the backplate layout. ## Switching Capacity and Duty Ratings The AC-3 rating of 1000 operations per hour at full motor current sets the thermal limit for frequent starting — a conveyor or pump cycling every 3.6 seconds would hit this ceiling. AC-4 (inching/plugging) drops to 300 ops/h, reflecting the higher arc energy during reversal. For resistive loads (AC-1), the contactor handles 900 ops/h. DC switching capacity is limited: 10 A at 24 V, 2 A at 60 V, 1 A at 110 V, 0.3 A at 220 V — the arc extinction in DC is harder, so these are the practical break limits. At 400 V, the AC-2 rating (slip-ring motor duty) is 37 kW, and AC-4 (reversing) is 66 A. The 690 V rating of 21.1 kW is the same contactor, same coil — no voltage-tap change needed.","metaTitle":"Siemens 3RT1045-1BB44 SIRIUS Power Contactor, 24 VDC Coil, S","metaDescription":"Siemens 3RT1045-1BB44 SIRIUS power contactor, size S3, 24 VDC coil, screw terminals, 45 kW at 500 V. Active production. Sourced to order against RFQ.","metaKeywords":null},"attributes":{"series":null,"packageCase":null,"mountingType":null,"rohsStatus":null,"productStatus":null,"categoryPath":["Contactors"],"specifications":{"Depth":"201 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":"146 mm","Stranded":"2x (10 ... 50 mm²)","Arcing Time":"10 ... 15 ms","Rated Value":"24 V","On The Front":"IP20; IP20 on the front with cover / box terminal","Initial Value":"0.8","During Storage":"-55 ... +80 °C","Of The Terminal":"IP00","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","During Operation":"-25 ... +60 °C","Fastening Method":"screw and snap-on mounting onto 35 mm and 75 mm standard mounting rail","Full-Scale Value":"1.1","Size Of Contactor":"S3","Solid Or Stranded":"2x (2.5 ... 16 mm²)","Product Brand Name":"SIRIUS","Degree Of Pollution":"3","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":"45 kW","at 690 V rated value":"21.1 kW","Side-By-Side Mounting":"Yes","at 1000 V rated value":"37 W","For Main Current Circuit":"screw-type terminals","at AC-2 at 400 V rated value":"37 kW","at AC-4 at 400 V rated value":"66 A","Substance Prohibitance (Date)":"05/01/2012","at 40 °C minimum permissible":"50 mm²","at 60 °C minimum permissible":"35 mm²","Insulation Voltage Rated Value":"1 000 V","at 230 V at 60 °C rated value":"38 kW","at 690 V at 60 °C rated value":"114 kW","at 1000 V at 60 °C rated value":"82 W","at AWG cables for main contacts":"2x (10 ... 1/0)","For Auxiliary And Control Circuit":"screw-type terminals","With Type Of Assignment 2 Required":"fuse gL/gG: 160 A","closing power of magnet coil at DC":"15 W","holding power of magnet coil at DC":"15 W","Surge Voltage Resistance Rated Value":"6 kV","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","Contact Reliability Of Auxiliary Contacts":"1 faulty switching per 100 million (17 V, 1 mA)","Thermal Short-Time Current Limited To 10 S":"760 A","Finely Stranded Without Core End Processing":"2x (10 ... 35 mm²)","Type Of Voltage Of The Control Supply Voltage":"DC","Required Spacing For Grounded Parts At The Side":"6 mm","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","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":null,"priceTiers":null},"links":{"datasheetUrl":null,"sourceUrl":"https://support.industry.siemens.com/webbackend/api/ProductSupport/TechnicalData?language=en&region=cn&productId=17220&mlfb=3RT1045-1BB44","alternativesUrl":"https://aoctrl.com/api/mcp/products/3RT1045-1BB44/alternatives.json"},"ai":{"faq":[{"question":"Will 3RT1045-1BB44 drop into a panel designed for 3RT1044-1FB46?","answer":"Both are SIRIUS power contactors in size S3 with the same 70 x 146 x 201 mm footprint and DIN-rail mounting, so the mechanical fit is identical. The difference is the coil voltage — 3RT1045-1BB44 uses 24 VDC, while 3RT1044-1FB46 uses a different coil rating. Verify the control voltage before swapping."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"matrix-langgraph","citationUrl":"https://aoctrl.com/siemens/3RT1045-1BB44","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/3RT1045-1BB44 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}}