{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"3RT1044-1BF44","brand":"Siemens","brandSlug":"siemens","productSlug":"3RT1044-1BF44","canonicalUrl":"https://aoctrl.com/siemens/3RT1044-1BF44","factsUrl":"https://aoctrl.com/api/mcp/products/3RT1044-1BF44","rawCanonicalId":null},"summary":{"shortDescription":"Siemens SIRIUS power contactor, size S3, 3RT1044-1BF44, 55 A AC-4 at 400 V, 110 V coil, screw-type terminals, screw and snap-on mounting.","salesMarkdown":"## Siemens SIRIUS 3RT1044-1BF44 — Power Contactor, Size S3 It is rated for AC-4 duty at 55 A at 400 V, which means it handles the toughest motor switching — plugging, inching, and reversing — where the contactor must break locked-rotor current. The 110 V coil keeps it compatible with common control transformer secondaries across North American and European panels. Mounts via screw fixing or snaps onto 35 mm or 75 mm DIN rail. The S3 frame — 70 mm wide, 146 mm tall, 201 mm deep — fits standard panel layouts with room for side-by-side mounting without derating. ## Switching Performance and Ratings Beyond the AC-4 rating, the contactor handles AC-2 duty at 30 kW at 400 V for slip-ring motors, and AC-1 resistive loads at up to 1,000 operations per hour. The DC switching capability is modest — 10 A at 24 V, 1 A at 110 V, 0.3 A at 220 V — so for DC loads, verify the rating against your circuit.","metaTitle":"Siemens 3RT1044-1BF44 SIRIUS Power Contactor, 55 A AC-4, 110","metaDescription":"Siemens SIRIUS 3RT1044-1BF44 power contactor, size S3. 55 A AC-4 at 400 V, 110 V coil. Screw terminals, DIN-rail mount. Current production. Quoted to order.","metaKeywords":null},"attributes":{"series":null,"packageCase":null,"mountingType":null,"rohsStatus":null,"productStatus":null,"categoryPath":["Contactors"],"specifications":{"Depth":"201 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":"110 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":"1 000 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":"37 kW","at 690 V rated value":"18.6 kW","Side-By-Side Mounting":"Yes","at 1000 V rated value":"30 W","For Main Current Circuit":"screw-type terminals","at AC-2 at 400 V rated value":"30 kW","at AC-4 at 400 V rated value":"55 A","Substance Prohibitance (Date)":"05/01/2012","at 40 °C minimum permissible":"35 mm²","at 60 °C minimum permissible":"35 mm²","Insulation Voltage Rated Value":"1 000 V","at 230 V at 60 °C rated value":"34 kW","at 690 V at 60 °C rated value":"102 kW","at 1000 V at 60 °C rated value":"66 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: 125 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":"600 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":"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,"priceTiers":null},"links":{"datasheetUrl":null,"sourceUrl":"https://support.industry.siemens.com/webbackend/api/ProductSupport/TechnicalData?language=en&region=cn&productId=197682&mlfb=3RT1044-1BF44","alternativesUrl":"https://aoctrl.com/api/mcp/products/3RT1044-1BF44/alternatives.json"},"ai":{"faq":[{"question":"Where can I buy the 3RT1044-1BF44 and get a price?","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 quote."},{"question":"What is the AC-4 rating of the 3RT1044-1BF44?","answer":"The contactor is rated 55 A at 400 V for AC-4 duty, which covers the most severe motor switching applications like reversing and inching."},{"question":"What compliance documentation does Siemens provide for the 3RT1044-1BF44?","answer":"RoHS compliance is confirmed with a substance prohibition date of May 1, 2012. The product is a Siemens SIRIUS series device and carries the standard CE marking for the European market."},{"question":"Will the 3RT1044-1BF44 drop into a panel specified around the 3RT1044-1FB46?","answer":"Both are size S3 SIRIUS contactors with the same mounting footprint (70 mm width, DIN-rail snap-on). The main difference is the coil voltage — the 1BF44 uses a 110 V coil while the 1FB46 uses a different coil voltage. Panel cutouts and busbar positions are identical, so no rewiring of the main circuit is needed if the coil supply matches."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"matrix-langgraph","citationUrl":"https://aoctrl.com/siemens/3RT1044-1BF44","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/3RT1044-1BF44 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}}