{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"3RT1044-1AL28-0PA4","brand":"Siemens","brandSlug":"siemens","productSlug":"3RT1044-1AL28-0PA4","canonicalUrl":"https://aoctrl.com/siemens/3RT1044-1AL28-0PA4","factsUrl":"https://aoctrl.com/api/mcp/products/3RT1044-1AL28-0PA4","rawCanonicalId":null},"summary":{"shortDescription":"Siemens SIRIUS power contactor, 3RT1044-1AL28-0PA4, size S3, 37 kW at 500 V AC-3, screw-type terminals, snap-on mounting.","salesMarkdown":"## Siemens SIRIUS 3RT1044-1AL28-0PA4 — Power Contactor, Size S3 It is rated for 37 kW at 500 V in AC-3 duty, meaning it handles the inrush and breaking of squirrel-cage motors up to that power level. The main current circuit uses screw-type terminals, accepting solid conductors from 0.5 mm² up to 4 mm² (two per clamp) and stranded conductors from 10 mm² to 50 mm² (two per clamp). This terminal range covers typical motor feeder cables from control to power distribution. The 37 kW rating at 500 V is the AC-3 motor switching capacity — the spec that determines whether this contactor handles your motor's locked-rotor current and break current. At 690 V the same contactor is rated for 18.6 kW, reflecting the higher voltage stress on the arc chamber. IP20 protection on the front with the cover or box terminal installed means the contactor is finger-safe in the panel but not protected against water ingress. The terminal area itself is rated IP00, so the panel enclosure provides the environmental seal. Dimensions are 146 mm height, 70 mm width, and 139 mm depth. The 70 mm width means it occupies roughly four 17.5 mm DIN-rail module spaces. Snap-on mounting onto 35 mm or 75 mm rail is standard, and the screw fixing option provides a positive lock in high-vibration environments. The contactor is rated for both 50 Hz and 60 Hz operation, with the operating range spanning 0.8 to 1.1 times rated voltage at 50 Hz and 0.85 to 1.1 at 60 Hz. This covers global line variations without adjustment.","metaTitle":"Siemens 3RT1044-1AL28-0PA4 SIRIUS Power Contactor, S3, 37 kW","metaDescription":"Siemens SIRIUS 3RT1044-1AL28-0PA4 power contactor, size S3, rated 37 kW at 500 V AC-3. Screw terminals, snap-on 35/75 mm rail. Current lifecycle stage.","metaKeywords":null},"attributes":{"series":null,"packageCase":null,"mountingType":null,"rohsStatus":null,"productStatus":null,"categoryPath":["Contactors"],"specifications":{"Depth":"139 mm","Solid":"2x (0.5 ... 1.5 mm²), 2x (0.75 ... 2.5 mm²), max. 2x (0.75 ... 4 mm²)","Width":"70 mm","at AC":"10 ... 19 ms","Height":"146 mm","Stranded":"2x (10 ... 50 mm²)","at 50 Hz":"0.8 ... 1.1","at 60 Hz":"0.85 ... 1.1","Arcing Time":"10 ... 15 ms","On The Front":"IP20; IP20 on the front with cover / box terminal","1 Rated Value":"50 Hz","2 Rated Value":"60 Hz","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","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 50 Hz rated value":"230 V","at 500 V rated value":"37 kW","at 60 Hz rated value":"230 V","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","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)","apparent holding power of magnet coil at AC":"25 VA","apparent pick-up power of magnet coil at AC":"247 VA","Type Of Voltage Of The Control Supply Voltage":"AC","Required Spacing For Grounded Parts At The Side":"6 mm","contact rating of auxiliary contacts according to UL":"A600 / Q600","Inductive Power Factor With Closing Power Of The Coil":"0.62","Installation Altitude At Height Above Sea Level Maximum":"2 000 m","Inductive Power Factor With The Holding Power Of The Coil":"0.27","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":"1","number of NO contacts for auxiliary contacts instantaneous contact":"1","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=217400&mlfb=3RT1044-1AL28-0PA4","alternativesUrl":"https://aoctrl.com/api/mcp/products/3RT1044-1AL28-0PA4/alternatives.json"},"ai":{"faq":[{"question":"What are the key dimensions for panel layout?","answer":"The contactor measures 146 mm high, 70 mm wide, and 139 mm deep. The 70 mm width corresponds to four 17.5 mm DIN-rail spaces."},{"question":"What wire sizes does the screw terminal accept?","answer":"The main circuit terminals accept solid conductors from 0.5 mm² to 4 mm² (two per clamp) and stranded conductors from 10 mm² to 50 mm² (two per clamp)."},{"question":"Can this contactor be mounted side-by-side without derating?","answer":"Yes, side-by-side mounting is permitted without derating, which allows dense panel layouts."},{"question":"What is the AC-3 motor rating at 500 V?","answer":"The contactor is rated for 37 kW at 500 V in AC-3 duty, which covers typical three-phase induction motor loads up to that power."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"matrix-langgraph","citationUrl":"https://aoctrl.com/siemens/3RT1044-1AL28-0PA4","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/3RT1044-1AL28-0PA4 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}}