{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"3RT1045-1AC20","brand":"Siemens","brandSlug":"siemens","productSlug":"3RT1045-1AC20","canonicalUrl":"https://aoctrl.com/siemens/3RT1045-1AC20","factsUrl":"https://aoctrl.com/api/mcp/products/3RT1045-1AC20","rawCanonicalId":null},"summary":{"shortDescription":"Siemens SIRIUS 3RT1045-1AC20, size S3 power contactor, 45 kW at 500 V AC-3, screw-type terminals, 50/60 Hz coil 24 V, DIN rail mount.","salesMarkdown":"The Siemens 3RT1045-1AC20 is a SIRIUS size S3 power contactor, rated for switching motor loads up to 45 kW at 500 V in AC-3 duty, or 21.1 kW at 690 V. The 24 V 50/60 Hz coil draws the listed inrush and hold values. This is the current-production variant — no obsolescence flag on record. The AC-1 rating (resistive load) would be higher, but for motor duty, AC-3 is the spec to match against your BOM. The AC-3 switching frequency is rated at 1 000 operating cycles per hour, which is typical for a size S3 contactor in conveyor or pump duty. The 24 V coil is rated for both 50 Hz and 60 Hz supply, with a tolerance band of 0.8 to 1.1 times rated voltage at 50 Hz and 0.85 to 1.1 at 60 Hz. The contactor carries IP20 on the front (finger-safe with cover/box terminal) and IP00 at the terminal itself — meaning the wiring area is not touch-safe without an additional enclosure. Side-by-side mounting is permitted, which saves panel width when grouping multiple contactors.","metaTitle":"Siemens 3RT1045-1AC20 SIRIUS Power Contactor, 45 kW at 500 V","metaDescription":"Siemens SIRIUS 3RT1045-1AC20 power contactor, size S3, 45 kW at 500 V AC-3. Current lifecycle stage. Screw terminals, DIN rail mount. Sourced to order against RFQ.","metaKeywords":null},"attributes":{"series":null,"packageCase":null,"mountingType":null,"rohsStatus":null,"productStatus":null,"categoryPath":["Contactors"],"specifications":{"Depth":"139 mm","Solid":"2x (0.5 ... 1.5 mm²), 2x (0.75 ... 2.5 mm²), max. 2x (0.75 ... 4 mm²)","Width":"70 mm","at AC":"10 ... 25 ms","Height":"146 mm","Stranded":"2x (10 ... 50 mm²)","at 50 Hz":"0.8 ... 1.1","at 60 Hz":"0.85 ... 1.1","Arcing Time":"10 ... 15 ms","On The Front":"IP20; IP20 on the front with cover / box terminal","1 Rated Value":"50 Hz","2 Rated Value":"60 Hz","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","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 50 Hz rated value":"24 V","at 500 V rated value":"45 kW","at 60 Hz rated value":"24 V","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","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)","apparent holding power of magnet coil at AC":"27 VA","apparent pick-up power of magnet coil at AC":"298 VA","Type Of Voltage Of The Control Supply Voltage":"AC","Required Spacing For Grounded Parts At The Side":"6 mm","contact rating of auxiliary contacts according to UL":"A600 / Q600","Inductive Power Factor With Closing Power Of The Coil":"0.7","Installation Altitude At Height Above Sea Level Maximum":"2 000 m","Inductive Power Factor With The Holding Power Of The Coil":"0.29","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":"0","number of NO contacts for auxiliary contacts instantaneous contact":"0","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=502288&mlfb=3RT1045-1AC20","alternativesUrl":"https://aoctrl.com/api/mcp/products/3RT1045-1AC20/alternatives.json"},"ai":{"faq":[{"question":"What is the closest functional alternative if I cannot source this exact order code?","answer":"The 3RT1036-1AB00 is a smaller size S2 contactor from the same SIRIUS family. It will not drop into the same footprint without panel modification — the S3 frame is physically larger (146 mm height, 70 mm width, 139 mm depth vs the S2 dimensions). The AC-3 motor rating is lower on the S2, so verify your load current before substituting."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"matrix-langgraph","citationUrl":"https://aoctrl.com/siemens/3RT1045-1AC20","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/3RT1045-1AC20 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}}