{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"3RT1044-1BD40","brand":"Siemens","brandSlug":"siemens","productSlug":"3RT1044-1BD40","canonicalUrl":"https://aoctrl.com/siemens/3RT1044-1BD40","factsUrl":"https://aoctrl.com/api/mcp/products/3RT1044-1BD40","rawCanonicalId":null},"summary":{"shortDescription":"Siemens SIRIUS power contactor, Size S3, 3RT1044-1BD40, screw terminals, 37 kW at 500 V AC-3, snap-on mounting.","salesMarkdown":"Rated at 37 kW at 500 V in AC-3 duty (standard motor switching) and 18.6 kW at 690 V, it covers the common European motor voltage bands. For heavy inrush or reversing duty, the AC-4 rating is 55 A at 400 V — that's the figure to check if the application involves plugging or jogging. AC-1 maximum switching frequency is 1 000 cycles per hour, which is fine for most pump and fan cycling; AC-4 maxes out at 300 cycles per hour — if the application needs faster reversing, the contactor will overheat. ## Termination and enclosure fit Solid wire capacity is 2x (0.5 to 1.5 mm²), 2x (0.75 to 2.5 mm²), max 2x (0.75 to 4 mm²); stranded accepts 2x (10 to 50 mm²) for the power connections. The control circuit terminals take 2x (2.5 to 16 mm²) solid or stranded. Dimensions are 146 mm high, 70 mm wide, 152 mm deep — the depth is the dimension that sticks out from the DIN rail, so check panel depth clearance. Substance prohibitance (RoHS) is declared per the date above. For UL, CSA, or other agency approvals, the nameplate and manufacturer declaration should be consulted; the evidence does not list specific marks, but SIRIUS contactors typically carry IEC and UL certifications.","metaTitle":"Siemens 3RT1044-1BD40 SIRIUS Power Contactor, Size S3, 37 kW","metaDescription":"Siemens 3RT1044-1BD40 SIRIUS power contactor, Size S3, 37 kW at 500 V AC-3, screw terminals, snap-on DIN rail, IP20 front, current lifecycle stage, RoHS compliant. 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":"42 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":"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=386650&mlfb=3RT1044-1BD40","alternativesUrl":"https://aoctrl.com/api/mcp/products/3RT1044-1BD40/alternatives.json"},"ai":{"faq":[{"question":"What is the depth of 3RT1044-1BD40?","answer":"The depth is 152 mm, measured from the mounting surface to the furthest point of the contactor body. This is the dimension that projects into the enclosure from the DIN rail."},{"question":"What solid wire sizes does the 3RT1044-1BD40 accept?","answer":"The main circuit screw terminals accept solid wire: 2x (0.5 to 1.5 mm²), 2x (0.75 to 2.5 mm²), and max 2x (0.75 to 4 mm²). Stranded power connections take 2x (10 to 50 mm²)."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"matrix-langgraph","citationUrl":"https://aoctrl.com/siemens/3RT1044-1BD40","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/3RT1044-1BD40 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}}