{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"3RT5045-1BF40","brand":"Siemens","brandSlug":"siemens","productSlug":"3RT5045-1BF40","canonicalUrl":"https://aoctrl.com/siemens/3RT5045-1BF40","factsUrl":"https://aoctrl.com/api/mcp/products/3RT5045-1BF40","rawCanonicalId":null},"summary":{"shortDescription":"Siemens SIRIUS 3RT5045-1BF40, size S3 power contactor, 110 V AC coil, screw terminals, snap-on mounting on 35 mm or 75 mm rail, rated 21.1 kW at 690 V.","salesMarkdown":"The 3RT5045-1BF40 is a SIRIUS size S3 power contactor with a 110 V AC coil. The 110 V control voltage is common in legacy European panels and some North American installations where a control transformer steps down from 480 V. The S3 frame size tells you the physical footprint: 70 mm wide, 146 mm high, 152 mm deep — so it occupies a standard four-module width on a 35 mm DIN rail and leaves room for side-by-side mounting without derating. Rated at 21.1 kW at 690 V AC-3e, this contactor handles motor loads up to that power in standard three-phase induction motor duty. If you are driving a pump, fan, or compressor at 690 V, this contactor carries the full motor current through the rated mechanical life of 10 million operations. The switching frequency limits tell you how often it can cycle without overheating: 1 000 operations per hour at AC-3e, 300 per hour at AC-4 (plugging/inching). That is a comfortable margin for a conveyor line cycling every few seconds; for a high-speed pick-and-place running 3 000 cycles per hour, you would need a larger frame or a contactor rated for higher frequency. Main circuit terminals are screw-type, accepting 2x (2.5 to 16 mm²) solid or stranded copper, or 2x (10 to 1/0 AWG). At 40 °C ambient, the minimum permissible conductor is 50 mm²; at 60 °C, it drops to 35 mm² — the higher temperature derates the current-carrying capacity, so you need a larger wire to keep the temperature rise within limits. Auxiliary and control circuits also use screw terminals, and the contactor accepts an auxiliary switch block (product extension available). For BOM freeze or PCN watch, this is a low-risk line item. The SIRIUS platform is Siemens' mainstream contactor family, widely stocked and supported. If you need to second-source, the closest functional peer is the 3RT5045-1AF00 (same S3 frame, same ratings, 110 V 50 Hz / 120 V 60 Hz coil) — it drops into the same panel footprint without rewiring, though the coil voltage differs slightly at 60 Hz. Verify the control transformer taps before swapping.","metaTitle":"Siemens 3RT5045-1BF40 SIRIUS Power Contactor, 110 V Coil, S3","metaDescription":"Siemens SIRIUS 3RT5045-1BF40 power contactor, size S3, 110 V AC coil, rated 21.1 kW at 690 V. Screw terminals, snap-on DIN rail. Current production. Available to order.","metaKeywords":null},"attributes":{"series":null,"packageCase":null,"mountingType":null,"rohsStatus":null,"productStatus":null,"categoryPath":["Contactors"],"specifications":{"Depth":"152 mm","Width":"70 mm","at DC":"1 000 1/h","Height":"146 mm","Rated Value":"110 V","During Storage":"-55 ... +80 °C","at AC-1 maximum":"900 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","at AC-3e maximum":"1 000 1/h","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 (2.5 ... 16 mm²)","Product Brand Name":"SIRIUS","Degree Of Pollution":"3","Product Designation":"Power contactor","at 24 V rated value":"6 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 690 V rated value":"21.1 kW","Side-By-Side Mounting":"Yes","For Main Current Circuit":"screw-type terminals","at AC-3e rated value maximum":"1 000 V","Substance Prohibitance (Date)":"03/01/2017","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 400 V at 60 °C rated value":"66 kW","at 690 V at 60 °C rated value":"114 kW","at AWG cables for main contacts":"2x (10 ... 1/0)","For Auxiliary And Control Circuit":"screw-type terminals","Product Extension Auxiliary Switch":"Yes","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","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)","at ambient temperature 40 °C rated value":"120 A","at ambient temperature 60 °C rated value":"100 A","Finely Stranded Without Core End Processing":"2x (10 ... 35 mm²)","Type Of Voltage Of The Control Supply Voltage":"DC","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"}},"commercial":{"minOrderQty":null,"leadTime":null,"referencePrice":null,"priceTiers":null},"links":{"datasheetUrl":"https://cdn.aoctrl.com/fd7cb6ea91fb3a54559b5c64236b25d7.pdf","sourceUrl":"https://support.industry.siemens.com/webbackend/api/ProductSupport/TechnicalData?language=en&region=cn&productId=580038&mlfb=3RT5045-1BF40","alternativesUrl":"https://aoctrl.com/api/mcp/products/3RT5045-1BF40/alternatives.json"},"ai":{"faq":[{"question":"Where can I buy 3RT5045-1BF40 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 a firm lead time."},{"question":"Will 3RT5045-1BF40 drop into a panel specified for 3RT5045-1AF00 without rewiring?","answer":"Yes, the 3RT5045-1BF40 shares the same S3 frame, mounting footprint, and terminal layout as the 3RT5045-1AF00. The only difference is the coil voltage: 110 V AC on this part versus 110 V 50 Hz / 120 V 60 Hz on the -1AF00. Check that your control transformer taps match before swapping."},{"question":"What compliance documentation does Siemens provide for 3RT5045-1BF40?","answer":"The part is RoHS compliant per the 2011/65/EU directive, with a substance prohibition date of 03/01/2017. Siemens typically provides a declaration of conformity (CE) and can supply UL/CSA certification on request through the distributor."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"matrix-langgraph","citationUrl":"https://aoctrl.com/siemens/3RT5045-1BF40","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/3RT5045-1BF40 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}}