{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"3RT1045-1AH20","brand":"Siemens","brandSlug":"siemens","productSlug":"3RT1045-1AH20","canonicalUrl":"https://aoctrl.com/siemens/3RT1045-1AH20","factsUrl":"https://aoctrl.com/api/mcp/products/3RT1045-1AH20","rawCanonicalId":null},"summary":{"shortDescription":"Siemens SIRIUS power contactor, S3 size, 3RT1045-1AH20, 45 kW at 500 V, 21.1 kW at 690 V, screw-type terminals, snap-on mounting.","salesMarkdown":"The Siemens SIRIUS 3RT1045-1AH20 is an S3-frame power contactor rated for motor switching at 45 kW on a 500 V 50 Hz line and 21.1 kW at 690 V. That 500 V rating tells you it's sized for a 3-phase motor pulling around 65 A in AC-3 duty — common for medium conveyors, pumps, or compressors in a 400 V to 500 V plant. The 690 V rating covers the 575/600 V class used in North American heavy industrial lines. The AC-3 switching rate of 1 000 operations per hour is the motor-duty limit — that's about one start every 3.6 seconds, which covers most conveyor and pump cycling. AC-4 drops to 300 per hour, reflecting the higher wear from plugging or inching. If your application needs frequent reversing, that 300/h ceiling is the one to watch. In a normal motor-starting cycle you'll get fewer electrical operations before the contacts wear, but the mechanical figure tells you the solenoid and linkage are built for the long haul. IP20 on the front with the cover or box terminal installed — that's finger-safe for the operator side. The terminal itself is IP00, so the wiring compartment needs enclosure protection in a washdown or outdoor cabinet. That 50 mm² stranded capacity is generous for an S3 contactor — it lets you land a 2/0 AWG equivalent without a ferrule or pin adapter. The auxiliary contacts handle 10 A at 24 V, 6 A at 230 V, and 3 A at 400 V, which covers most PLC output and relay coil circuits.","metaTitle":"Siemens SIRIUS 3RT1045-1AH20 Power Contactor, S3, 500V 45kW","metaDescription":"Siemens SIRIUS 3RT1045-1AH20 S3 power contactor. 45 kW at 500 V, 21.1 kW at 690 V. Screw terminals, snap-on DIN rail. Current lifecycle stage. 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":"48 V","at 500 V rated value":"45 kW","at 60 Hz rated value":"48 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=301215&mlfb=3RT1045-1AH20","alternativesUrl":"https://aoctrl.com/api/mcp/products/3RT1045-1AH20/alternatives.json"},"ai":{"faq":[{"question":"What are the key motor ratings for this contactor?","answer":"It is rated 45 kW at 500 V 50 Hz and 21.1 kW at 690 V. The coil is 48 V at 50/60 Hz."},{"question":"What wire sizes does the main circuit accept?","answer":"Solid: 2x (0.5 to 1.5 mm²), 2x (0.75 to 2.5 mm²), max 2x (0.75 to 4 mm²). Stranded: 2x (10 to 50 mm²)."},{"question":"What is the physical size of this contactor?","answer":"Depth 139 mm, width 70 mm, height 146 mm. It mounts on 35 mm or 75 mm DIN rail."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"matrix-langgraph","citationUrl":"https://aoctrl.com/siemens/3RT1045-1AH20","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/3RT1045-1AH20 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}}