{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"3RT1044-1AH28-0PA4","brand":"Siemens","brandSlug":"siemens","productSlug":"3RT1044-1AH28-0PA4","canonicalUrl":"https://aoctrl.com/siemens/3RT1044-1AH28-0PA4","factsUrl":"https://aoctrl.com/api/mcp/products/3RT1044-1AH28-0PA4","rawCanonicalId":null},"summary":{"shortDescription":"Siemens SIRIUS 3RT1044-1AH28-0PA4, size S3 power contactor, 37 kW at 500 V AC-3, screw-type terminals, 50/60 Hz coil, 146 x 80 x 139 mm.","salesMarkdown":"## SIRIUS S3 Power Contactor — 37 kW at 500 V The Siemens 3RT1044-1AH28-0PA4 is a SIRIUS size S3 power contactor rated for 37 kW at 500 V in AC-3 duty — that's the motor-switching rating that governs the real-world fit for pumps, fans, and compressors up to that load. The AC-3 maximum switching rate of 1 000 cycles per hour means it can keep up with frequent start-stop sequences on a conveyor or batch process without exceeding thermal limits. Mechanical life is typical at 10 000 000 operations, so the contactor itself outlasts most panel rebuild cycles. The coil operates on 50 Hz or 60 Hz supply with a rated voltage of 48 V, and the operating range spans 0.8 to 1.1 times nominal at 50 Hz and 0.85 to 1.1 at 60 Hz — wide enough to handle a sagging line without dropping out. The 24 V DC auxiliary contact rating is 10 A, which covers pilot-duty loads like PLC inputs or indicator lamps. ## Mounting and Wiring — DIN Rail, Screw Terminals Dimensions are 146 mm high, 80 mm wide, 139 mm deep. Main circuit terminals are screw-type, accepting solid conductors from 2x 0.5 mm² up to 2x 4 mm², and stranded from 2x 10 mm² up to 2x 50 mm². That range covers control wiring through motor feeders. Terminal protection is IP00, but the front face carries IP20 with the cover or box terminal fitted — enough for finger-safe touch protection inside a closed panel. ## Environmental and Duty Ratings Switching rates vary by duty class: AC-1 (resistive) max 1 000 cycles/h, AC-2 (slip-ring motors) max 400 cycles/h, AC-3 (squirrel-cage motors) max 1 000 cycles/h, AC-4 (plugging/inching) max 300 cycles/h.","metaTitle":"Siemens 3RT1044-1AH28-0PA4 SIRIUS Power Contactor, S3, 37 kW","metaDescription":"Siemens SIRIUS 3RT1044-1AH28-0PA4 power contactor, size S3, rated 37 kW at 500 V AC-3. Screw terminals, 50/60 Hz coil. Current lifecycle stage. Sourced to order.","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":"80 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":"48 V","at 500 V rated value":"37 kW","at 60 Hz rated value":"48 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=92261&mlfb=3RT1044-1AH28-0PA4","alternativesUrl":"https://aoctrl.com/api/mcp/products/3RT1044-1AH28-0PA4/alternatives.json"},"ai":{"faq":[{"question":"What is the closest functional second-source for 3RT1044-1AH28-0PA4?","answer":"The 3RT1044-1FB46 is a peer in the same SIRIUS S3 frame, but it uses a different coil voltage and terminal arrangement — verify the coil rating and wiring footprint before substituting. The 3RT5044-1BM40 and 3RT5045-1AC20 are also SIRIUS contactors but in different size frames; they are not drop-in replacements without panel rework."},{"question":"What wire sizes does the 3RT1044-1AH28-0PA4 accept?","answer":"Solid conductors: 2x 0.5 to 1.5 mm², 2x 0.75 to 2.5 mm², max 2x 0.75 to 4 mm². Stranded: 2x 10 to 50 mm². Terminals are screw-type."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"matrix-langgraph","citationUrl":"https://aoctrl.com/siemens/3RT1044-1AH28-0PA4","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/3RT1044-1AH28-0PA4 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}}