{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"3RT1044-3BB44-3MA0","brand":"Siemens","brandSlug":"siemens","productSlug":"3RT1044-3BB44-3MA0","canonicalUrl":"https://aoctrl.com/siemens/3RT1044-3BB44-3MA0","factsUrl":"https://aoctrl.com/api/mcp/products/3RT1044-3BB44-3MA0","rawCanonicalId":null},"summary":{"shortDescription":"Siemens SIRIUS S3 power contactor, 3RT1044-3BB44-3MA0, 55 A AC-4 at 400 V, 37 kW at 500 V, screw terminals, DIN-rail mount.","salesMarkdown":"## SIRIUS S3 power contactor — 55 A AC-4, 37 kW at 500 V The Siemens 3RT1044-3BB44-3MA0 is a SIRIUS S3-frame power contactor, rated for 55 A in AC-4 duty at 400 V — that's the switching category for reversing, inching, and plugging motor loads where the contactor makes and breaks stalled-rotor current. At 500 V it carries 37 kW, sized for a typical 37 kW four-pole induction motor on a 500 V three-phase line. Mounts on 35 mm or 75 mm standard DIN rail via screw and snap-on fastening; side-by-side mounting is permitted. S3 frame: 146 mm high, 70 mm wide, 201 mm deep. Main current circuit terminations are screw-type, accepting 2x (10–50 mm²) stranded or 2x (0.25–2.5 mm²) solid conductors. The front of the contactor carries IP20 protection with the cover or box terminal fitted; the terminal itself is IP00, so panel builders should account for that in the enclosure IP rating. ## DC switching capacity — what the curve means The DC switching ratings are given at several voltage points: 10 A at 24 V, 2 A at 60 V, 1 A at 110 V, 0.3 A at 220 V, 6 A at 230 V, and 3 A at 400 V. These are the maximum resistive DC currents the contactor can break at each voltage — not a continuous carry rating. For a 24 VDC control circuit or a small DC motor brake, the 10 A figure gives headroom; above 60 V the curve drops steeply, so a 110 VDC solenoid bank pulling 1 A is at the limit. Side-by-side mounting is allowed. Depth is 201 mm.","metaTitle":"Siemens 3RT1044-3BB44-3MA0 SIRIUS S3 Power Contactor, 55 A A","metaDescription":"Siemens 3RT1044-3BB44-3MA0 SIRIUS S3 power contactor, 55 A AC-4 at 400 V, 37 kW at 500 V. Screw terminals, DIN-rail mount. Current lifecycle stage. Sourced to order.","metaKeywords":null},"attributes":{"series":null,"packageCase":null,"mountingType":null,"rohsStatus":null,"productStatus":null,"categoryPath":["Contactors"],"specifications":{"Depth":"201 mm","Solid":"2x (0.25 ... 2.5 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":"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":"spring-loaded 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 (24 ... 14)","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 (0.25 ... 1.5 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 (0.25 ... 2.5 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=15679&mlfb=3RT1044-3BB44-3MA0","alternativesUrl":"https://aoctrl.com/api/mcp/products/3RT1044-3BB44-3MA0/alternatives.json"},"ai":{"faq":[{"question":"Will 3RT1044-3BB44-3MA0 drop into a panel specified for 3RT1044-1FB46?","answer":"Both are SIRIUS S3-frame contactors with screw terminals and the same DIN-rail mounting footprint, so the mechanical fit is identical. The electrical ratings differ — verify the coil voltage and switching category match your application before substituting."},{"question":"What is the depth of 3RT1044-3BB44-3MA0?","answer":"The depth is 201 mm, which is the dimension from the mounting rail to the furthest front projection including the cover."},{"question":"What solid conductor size does the terminal accept?","answer":"The screw terminals accept 2x (0.25 to 2.5 mm²) solid conductors for the control circuit; the main power circuit uses 2x (10 to 50 mm²) stranded."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"matrix-langgraph","citationUrl":"https://aoctrl.com/siemens/3RT1044-3BB44-3MA0","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/3RT1044-3BB44-3MA0 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}}