{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"3RT1045-1CP04","brand":"Siemens","brandSlug":"siemens","productSlug":"3RT1045-1CP04","canonicalUrl":"https://aoctrl.com/siemens/3RT1045-1CP04","factsUrl":"https://aoctrl.com/api/mcp/products/3RT1045-1CP04","rawCanonicalId":null},"summary":{"shortDescription":"Siemens SIRIUS power contactor, S3 frame, 3RT1045-1CP04, 37 kW at 400 V AC-2, 66 A AC-4, screw-type terminals, IP20 front, snap-on mounting.","salesMarkdown":"It carries a 37 kW rating at 400 V under AC-2 duty (slip-ring motor start/run) and 66 A under AC-4 (plugging/inching duty), which tells you it's sized for heavy reversing or jogging applications, not just across-the-line starting. The S3 frame (146 mm high, 70 mm wide, 188 mm deep) is the mid-size in the SIRIUS contactor family, meaning it fits alongside other SIRIUS gear in a coordinated panel layout. Side-by-side mounting is allowed, which saves rail space when grouping multiple contactors. ## Ratings in Context The AC-3 rating (not explicitly listed here, but the S3 frame typically covers 32–45 kW at 400 V) is the one that governs general squirrel-cage motor switching. The AC-4 rating of 66 A at 400 V is the figure that matters for reversing or inching duty — it's higher than the AC-2 kW number because AC-4 is current-based, not power-based. If you're replacing a contactor in a crane or hoist panel where plugging happens, the AC-4 current is the spec to match. ## Environmental and Protection IP20 on the front with the cover or box terminal installed; the terminal area itself is IP00, so it expects enclosure protection for the wiring compartment.","metaTitle":"Siemens SIRIUS 3RT1045-1CP04 Power Contactor, S3, 37 kW at 4","metaDescription":"Siemens SIRIUS 3RT1045-1CP04 power contactor, S3 frame, 37 kW at 400 V AC-2, 66 A AC-4. Current lifecycle stage. Screw and snap-on mounting. IP20 front. Sourced to order against RF","metaKeywords":null},"attributes":{"series":null,"packageCase":null,"mountingType":null,"rohsStatus":null,"productStatus":null,"categoryPath":["Contactors"],"specifications":{"Depth":"188 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":"10.6g / 5 ms, 6.2g / 10 ms","at DC":"14 ... 20 ms","Height":"146 mm","Stranded":"2x (10 ... 50 mm²)","at 50 Hz":"0.8 ... 1.1","Arcing Time":"10 ... 15 ms","On The Front":"IP20; IP20 on the front with cover / box terminal","1 Rated Value":"50 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":"230 V","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","Design Of The Surge Suppressor":"with varistor","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":"22 VA","apparent pick-up power of magnet coil at AC":"270 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":"0.68","Installation Altitude At Height Above Sea Level Maximum":"2 000 m","Inductive Power Factor With The Holding Power Of The Coil":"0.27","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=344005&mlfb=3RT1045-1CP04","alternativesUrl":"https://aoctrl.com/api/mcp/products/3RT1045-1CP04/alternatives.json"},"ai":{"faq":[{"question":"What are the key motor ratings for this contactor?","answer":"It is rated 37 kW at 400 V under AC-2 duty and 66 A at 400 V under AC-4 duty, covering slip-ring motor starting and heavy reversing/inching applications."},{"question":"What is the physical size and mounting method?","answer":"Dimensions are 146 mm height, 70 mm width, and 188 mm depth. It mounts via screw or snap-on onto 35 mm or 75 mm standard mounting rail."},{"question":"What IP rating does it have?","answer":"IP20 on the front with the cover or box terminal installed; the terminal area itself is IP00, so it requires enclosure protection for the wiring compartment."},{"question":"What temperature range can it operate in?","answer":"Operating temperature is -25 to +60 °C, with storage from -55 to +80 °C."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"matrix-langgraph","citationUrl":"https://aoctrl.com/siemens/3RT1045-1CP04","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/3RT1045-1CP04 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}}