{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"3RT1045-1BB40","brand":"Siemens","brandSlug":"siemens","productSlug":"3RT1045-1BB40","canonicalUrl":"https://aoctrl.com/siemens/3RT1045-1BB40","factsUrl":"https://aoctrl.com/api/mcp/products/3RT1045-1BB40","rawCanonicalId":null},"summary":{"shortDescription":"Siemens SIRIUS power contactor, size S3, 24 VDC coil, screw-type terminals, 45 kW at 500 V AC-3, 70 mm width, snap-on mounting.","salesMarkdown":"Its 24 V DC coil (rated value 24 V) picks up at 0.8 x Us and drops out at 1.1 x Us, with a DC arcing time of 14 to 20 ms and an AC arcing time of 10 to 15 ms — the DC arcing characteristic matters when breaking inductive DC loads, where the arc extinguishes slower than on AC. Rated for AC-3 duty at 45 kW on 500 V and 21.1 kW on 690 V, this contactor handles the motor starting and running currents typical of pumps, fans, and compressors in the 30–60 hp range on 400 V systems. Main circuit terminals are screw-type, accepting solid conductors 2x (0.5 to 1.5 mm²), 2x (0.75 to 2.5 mm²), max 2x (0.75 to 4 mm²), and stranded conductors 2x (10 to 50 mm²) and 2x (2.5 to 16 mm²). The IP20 rating on the front with cover or box terminal means the contactor is finger-safe once installed in an enclosure; the terminal body itself is IP00, so live parts are exposed until the enclosure door is closed. The substance prohibition date of 05/01/2012 aligns with RoHS compliance; expect REACH and RoHS documentation with the shipment. ## DC Switching Capability The contactor is rated for DC switching at several voltage levels: 10 A at 24 V, 2 A at 60 V, 1 A at 110 V, and 0.3 A at 220 V. These ratings are for resistive DC loads; inductive DC loads (solenoids, DC motor brakes) require derating or arc-suppression measures because the DC arcing time of 14 to 20 ms is longer than the AC arcing time. ## Mechanical Endurance Typical mechanical life is 10 000 000 operations. Electrical life depends on the duty cycle: AC-1 (resistive) allows 900 operations per hour, AC-2 (slip-ring motors) 400 ops/h, AC-3 (squirrel-cage motors) 1 000 ops/h, and AC-4 (reversing/inching) 300 ops/h. The mechanical life figure means the contactor itself will outlast most motor-driven equipment in normal service.","metaTitle":"Siemens 3RT1045-1BB40 SIRIUS Power Contactor, 24 VDC Coil, S","metaDescription":"Siemens 3RT1045-1BB40 SIRIUS power contactor, size S3, 24 VDC coil. Rated 45 kW at 500 V AC-3. Screw terminals, snap-on DIN rail mounting. Current lifecycle stage. Sourced to order","metaKeywords":null},"attributes":{"series":null,"packageCase":null,"mountingType":null,"rohsStatus":null,"productStatus":null,"categoryPath":["Contactors"],"specifications":{"Depth":"152 mm","Solid":"2x (0.5 ... 1.5 mm²), 2x (0.75 ... 2.5 mm²), max. 2x (0.75 ... 4 mm²)","Width":"70 mm","at DC":"14 ... 20 ms","Height":"146 mm","Stranded":"2x (10 ... 50 mm²)","Arcing Time":"10 ... 15 ms","Rated Value":"24 V","On The Front":"IP20; IP20 on the front with cover / box terminal","Initial Value":"0.8","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","Full-Scale Value":"1.1","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 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","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","closing power of magnet coil at DC":"15 W","holding power of magnet coil at DC":"15 W","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)","Type Of Voltage Of The Control Supply Voltage":"DC","Required Spacing For Grounded Parts At The Side":"6 mm","contact rating of auxiliary contacts according to UL":"A600 / Q600","Installation Altitude At Height Above Sea Level Maximum":"2 000 m","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=239460&mlfb=3RT1045-1BB40","alternativesUrl":"https://aoctrl.com/api/mcp/products/3RT1045-1BB40/alternatives.json"},"ai":{"faq":[{"question":"Where can I buy 3RT1045-1BB40 and what is the lead time?","answer":"This part is sourced and quoted to order against an RFQ through independent distribution. Availability and current pricing are confirmed at quote time — submit an RFQ for your quantity and timeline."},{"question":"What is the depth of 3RT1045-1BB40?","answer":"The depth is 152 mm. Combined with the width of 70 mm and height of 146 mm, the contactor fits standard panel layouts and leaves clearance for wiring ducts and cable bends."},{"question":"What compliance documentation does Siemens provide for 3RT1045-1BB40?","answer":"The part has a substance prohibition date of 05/01/2012, indicating RoHS compliance. Expect RoHS and REACH declarations with the shipment. The IP20 front rating and pollution degree 3 classification support UL and IEC listing for industrial control equipment."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"matrix-langgraph","citationUrl":"https://aoctrl.com/siemens/3RT1045-1BB40","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/3RT1045-1BB40 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}}