{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"3RT2045-3AC20","brand":"Siemens","brandSlug":"siemens","productSlug":"3RT2045-3AC20","canonicalUrl":"https://aoctrl.com/siemens/3RT2045-3AC20","factsUrl":"https://aoctrl.com/api/mcp/products/3RT2045-3AC20","rawCanonicalId":null},"summary":{"shortDescription":"Siemens SIRIUS power contactor, 3RT2045-3AC20, size S3, 70 mm width, spring-type terminals, screw and snap-on mounting on 35 mm DIN rail.","salesMarkdown":"## Integrator note — SIRIUS 3RT2045-3AC20 Spring-type terminals on the coil and main contacts — no screw torque to check, just strip and push. The 70 mm width and 152 mm depth fit a standard 35 mm DIN rail (DIN EN 60715) with screw or snap-on mounting; the mounting position allows ±180° rotation on a vertical surface and ±22.5° tilt forward/backward, which helps when the panel layout is tight. ## Terminal & wire handling Main circuit accepts solid conductors 2.5 to 16 mm² and stranded 6 to 70 mm² — the spring cage handles the larger stranded sizes common on motor feeders. Auxiliary contacts take 2x (0.5 to 2.5 mm²) solid or stranded. That covers most panel wiring from control signals to power tails without needing adapters. ## Environmental & mounting flexibility That's tighter than many contactors, so panel fill factor is better than average for a size S3.","metaTitle":"Siemens 3RT2045-3AC20 SIRIUS Power Contactor, S3, 70 mm, Spr","metaDescription":"Siemens 3RT2045-3AC20 SIRIUS power contactor, size S3, 70 mm width, spring-type terminals, rated for AC-3 duty at 1,000 ops/h. Current lifecycle stage. Sourced to order against RFQ","metaKeywords":null},"attributes":{"series":null,"packageCase":null,"mountingType":null,"rohsStatus":null,"productStatus":"Active","categoryPath":["Contactors"],"specifications":{"Depth":"152 mm","Solid":"2.5 ... 16 mm²","Width":"70 mm","at AC":"10 ... 21 ms","Height":"140 mm","Upwards":"10 mm","Forwards":"20 mm","Stranded":"6 ... 70 mm²","at 50 Hz":"0.35","at 60 Hz":"0.41","Downwards":"10 mm","Arcing Time":"10 ... 20 ms","At The Side":"10 mm","During Storage":"-55 ... +80 °C","Of Magnet Coil":"Spring-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 standard mounting 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 ... 2.5 mm²)","Product Brand Name":"SIRIUS","Product Designation":"Power contactor","at 24 V rated value":"10 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":"24 V","at 500 V rated value":"2 A","at 60 Hz rated value":"24 V","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":"spring-loaded 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":"25 W","At Contactor For Auxiliary Contacts":"Spring-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)","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)","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 %","Finely Stranded Without Core End Processing":"2x (0.5 ... 2.5 mm²)","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":"1","number of NO contacts for auxiliary contacts instantaneous contact":"1","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":"https://cdn.aoctrl.com/7d28fa7380658c541019ac8751bc4da6.pdf","sourceUrl":"https://support.industry.siemens.com/webbackend/api/ProductSupport/TechnicalData?language=en&region=cn&productId=629815&mlfb=3RT2045-3AC20","alternativesUrl":"https://aoctrl.com/api/mcp/products/3RT2045-3AC20/alternatives.json"},"ai":{"faq":[{"question":"Where can I buy 3RT2045-3AC20 and how is it quoted?","answer":"Sourced and quoted to order against an RFQ through independent distribution. Availability and current pricing are confirmed at quote time — no stock count or price is published here."},{"question":"What is the closest functional second-source to 3RT2045-3AC20?","answer":"The 3RT5045-1AC20 is a peer in the same SIRIUS family, also size S3, but with screw terminals instead of spring-type. The 3RT2045-3AC20 uses spring-type terminals, so swapping to the 3RT5045-1AC20 means changing the termination method — the footprint and mounting rail are the same, but the wiring preparation differs (ferrules vs. bare wire)."},{"question":"What is 3RT2045-3AC20's listed depth?","answer":"152 mm."},{"question":"What solid conductor range does 3RT2045-3AC20 accept?","answer":"2.5 to 16 mm² solid on the main circuit."},{"question":"Will 3RT2045-3AC20 drop into a panel specified around 3RT5045-1AC20 without rewiring?","answer":"The mounting footprint and DIN rail position are the same — both are size S3. The difference is terminal type: 3RT2045-3AC20 uses spring-type terminals, while 3RT5045-1AC20 uses screw terminals. If the panel was wired for screw terminals (ring or fork lugs), the spring cage on this part requires ferruled stranded or bare solid wire — no lugs. So the panel wiring method must change."},{"question":"What compliance documentation does Siemens provide for 3RT2045-3AC20?","answer":"The evidence does not list specific certifications (UL, CSA, CE, RoHS, REACH) for this order code. Standard Siemens SIRIUS contactors typically carry CE and UL/CSA markings, but confirm the exact documentation with the supplier at quote time."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"matrix-langgraph","citationUrl":"https://aoctrl.com/siemens/3RT2045-3AC20","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/3RT2045-3AC20 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}}