{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"3RT1045-1AL28-0PA4","brand":"Siemens","brandSlug":"siemens","productSlug":"3RT1045-1AL28-0PA4","canonicalUrl":"https://aoctrl.com/siemens/3RT1045-1AL28-0PA4","factsUrl":"https://aoctrl.com/api/mcp/products/3RT1045-1AL28-0PA4","rawCanonicalId":null},"summary":{"shortDescription":"Siemens SIRIUS 3RT1 power contactor, order code 3RT1045-1AL28-0PA4, AC-3 80 A / 37 kW at 400 V, 230 V AC 50/60 Hz coil, 3-pole, Size S3, screw terminals, 1 NO + 1 NC auxiliary contacts.","salesMarkdown":"The Siemens 3RT1045-1AL28-0PA4 is a 3-pole power contactor from the SIRIUS 3RT1 series, rated for AC-3 duty at 80 A and 37 kW at 400 V. The 230 V AC coil operates at 50/60 Hz. The AC-3 rating is the motor-switching curve — this contactor is sized for starting and stopping squirrel-cage induction motors under full load, not for resistive heating or DC loads. The Size S3 frame carries screw terminals and includes one normally-open and one normally-closed auxiliary contact mounted on the lateral right side. ## Integration notes The Size S3 footprint mounts on standard DIN rail in a control panel. The 230 V AC coil draws its control voltage from the panel's line side — verify the control transformer rating if multiple contactors share the same circuit. The auxiliary contact block (1 NO + 1 NC) is factory-fitted on the lateral right; no additional side-mounting hardware is needed for basic feedback or interlock wiring. Screw terminals accept up to the wire gauge specified for 80 A motor branch circuits.","metaTitle":"Siemens 3RT1045-1AL28-0PA4 Power Contactor, AC-3 80 A, 37 kW","metaDescription":"Siemens 3RT1045-1AL28-0PA4 power contactor, AC-3 80 A / 37 kW at 400 V, 230 VAC coil, 3-pole, Size S3. Phased-out product; successor is SIRIUS 3RT2 series. Sourced to order against","metaKeywords":null},"attributes":{"series":null,"packageCase":null,"mountingType":null,"rohsStatus":null,"productStatus":null,"categoryPath":["Contactors"],"specifications":{"lifecycle_stage":"current"}},"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=182138&mlfb=3RT1045-1AL28-0PA4","alternativesUrl":"https://aoctrl.com/api/mcp/products/3RT1045-1AL28-0PA4/alternatives.json"},"ai":{"faq":[{"question":"What replaces the 3RT1045-1AL28-0PA4?","answer":"The official successor is the SIRIUS 3RT2 series. The exact order code depends on the required coil voltage and auxiliary contact configuration. The 3RT2 is a form-fit-function replacement for the 3RT1 series."},{"question":"What are the key ratings for this contactor?","answer":"AC-3 motor switching duty at 80 A, 37 kW at 400 V. The coil is 230 V AC, 50/60 Hz. Three poles, Size S3 frame, screw terminals, with 1 NO + 1 NC auxiliary contacts on the lateral right side."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"matrix-langgraph","citationUrl":"https://aoctrl.com/siemens/3RT1045-1AL28-0PA4","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/3RT1045-1AL28-0PA4 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}}