{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"3RT2045-1AF04","brand":"Siemens","brandSlug":"siemens","productSlug":"3RT2045-1AF04","canonicalUrl":"https://aoctrl.com/siemens/3RT2045-1AF04","factsUrl":"https://aoctrl.com/api/mcp/products/3RT2045-1AF04","rawCanonicalId":null},"summary":{"shortDescription":"Siemens SIRIUS 3RT2045-1AF04 power contactor, size S3, 77 A at 480 V AC-3, 3-pole, screw-type terminals, 35 mm DIN rail snap-on mounting.","salesMarkdown":"## Panel fit and mounting constraints The 3RT2045-1AF04 occupies a 70 mm wide footprint on the DIN rail, with a depth of 195 mm from the rail face to the back of the enclosure — enough to clear most 200 mm deep gland plates, but tight in shallow retrofit cans. Mounting is screw or snap-on onto standard 35 mm DIN rail per DIN EN 60715; the contactor can be rotated ±180° on a vertical surface and tilted ±22.5° forward or backward, which helps when the panel layout forces an odd orientation. Clearance requirements: 10 mm upwards, 10 mm downwards, 10 mm at the side, and 20 mm forwards from the front face — plan the surrounding component placement around these gaps to avoid heat buildup or arc flash interference. ## Termination and wire sizing Main power terminals accept solid wire from 2.5 mm² up to 16 mm², or stranded wire from 6 mm² to 70 mm² — the larger stranded range covers the full ampacity for the 77 A AC-3 rating without needing a ferrule stack. Auxiliary and coil terminals use screw-type connections accepting 2x (0.5–1.5 mm²) or 2x (0.75–2.5 mm²) solid or stranded — common for the 24 V control wiring in a standard panel. ## Switching performance and operating rates Arcing time runs 10–20 ms at AC; the contactor is rated for 1,000 operations per hour at AC-3 (motor switching) and 300 per hour at AC-4 (plugging/inching) — the AC-4 ceiling is the limiting factor for high-duty-cycle applications like reversing starters. Mechanical life is 10 million operations typical, which aligns with the SIRIUS S3 frame size — expect the electrical life to be lower under full-load AC-3 switching, but the mechanical endurance gives headroom for lightly loaded or no-load cycling. ## Environmental and lifecycle status Operating temperature range is -25 °C to +60 °C; storage range extends from -55 °C to +80 °C — the wider storage window matters for spares held in unheated warehouses.","metaTitle":"Siemens 3RT2045-1AF04 SIRIUS Power Contactor, 77 A at 480 V","metaDescription":"Siemens 3RT2045-1AF04 SIRIUS power contactor, size S3. Rated 77 A at 480 V AC-3. Active production, screw & snap-on DIN rail mount. Available to order.","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":"10 ... 21 ms","title":"3RT2045-1AF04","Height":"140 mm","Upwards":"10 mm","Forwards":"20 mm","Stranded":"6 ... 70 mm²","at 50 Hz":"0.38","Downwards":"10 mm","Arcing Time":"10 ... 20 ms","At The Side":"10 mm","description":"power contactor, AC-3e/AC-3, 80 A, 37 kW / 400 V, 3-pole, 110 V AC, 50 Hz, auxiliary contacts: 2 NO + 2 NC, screw terminal, size: S3, removable auxiliary switch","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","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","Product Designation":"Power 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 50 Hz rated value":"110 V","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","Relative Humidity Minimum":"10 %","Of Main Circuit Rated Value":"8 kV","Safety-Related Switching On":"Yes","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","at AWG cables for main contacts":"2x (10 ... 1/0), 1x (10 ... 2)","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":"19 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)","at AWG cables for auxiliary contacts":"2x (20 ... 16), 2x (18 ... 14)","operational current at AC-12 maximum":"10 A","at AC in hot operating state per pole":"5.3 W","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":"AC","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":null,"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=629766&mlfb=3RT2045-1AF04"},"ai":{"faq":[{"question":"What is the 3RT2045-1AF04 rated for at 480 V?","answer":"At 480 V AC-3 duty, the contactor is rated 77 A — this is the motor switching current for a typical 40–50 hp motor at that voltage."},{"question":"What wire sizes does the 3RT2045-1AF04 accept on the main terminals?","answer":"The main power terminals accept solid wire from 2.5 mm² to 16 mm², and stranded wire from 6 mm² to 70 mm² — the larger stranded range covers the full 77 A rating without needing parallel conductors."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"icboms-matrix-langgraph","citationUrl":"https://aoctrl.com/siemens/3RT2045-1AF04","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/3RT2045-1AF04 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}}