{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"5SL7440-3RC","brand":"Siemens","brandSlug":"siemens","productSlug":"5SL7440-3RC","canonicalUrl":"https://aoctrl.com/siemens/5SL7440-3RC","factsUrl":"https://aoctrl.com/api/mcp/products/5SL7440-3RC","rawCanonicalId":null},"summary":{"shortDescription":"Siemens 5SL7440-3RC, Miniature Circuit Breaker, 40A, 4-pole, K characteristic, 15kA breaking capacity.","salesMarkdown":"The 40 A rating governs the continuous load it can carry — sized for a feeder or a large motor branch circuit. The 4-pole construction (all four poles switched and protected) suits three-phase loads plus a neutral, common in European-style distribution panels. The K characteristic's magnetic trip threshold sits between a B-curve (for resistive/light loads) and a C-curve (general-purpose), making it the right pick for circuits where motor inrush or transformer magnetizing current would otherwise trip a standard breaker. The 15 kA breaking capacity is the fault-interruption limit; in a panel with a high available fault current, this breaker holds its coordination downstream without cascading failures upstream. The 4-pole width is four modular units (72 mm on a 18 mm/module rail). Wire terminals accept copper conductors up to the rated cross-section for a 40 A device — typically 10 mm² for the line and load sides. The toggle handle indicates trip status visually; the K-curve's magnetic trip operates faster than a thermal-only breaker on a hard short.","metaTitle":"Siemens 5SL7440-3RC MCB 40A 4P K 15kA","metaDescription":"Siemens 5SL7440-3RC miniature circuit breaker, 40A, 4-pole, K characteristic, 15kA breaking capacity. Lifecycle stage: current. Available to order, quoted on request.","metaKeywords":null},"attributes":{"series":null,"packageCase":null,"mountingType":null,"rohsStatus":null,"productStatus":null,"categoryPath":["Miniature Circuit Breakers (MCB)"],"specifications":{"lifecycle_stage":"current"}},"commercial":{"minOrderQty":null,"leadTime":null,"referencePrice":null,"priceTiers":null},"links":{"datasheetUrl":"https://cdn.aoctrl.com/dc60340626e645e05106be8c91d57c59.pdf","sourceUrl":"https://support.industry.siemens.com/webbackend/api/ProductSupport/TechnicalData?language=en&region=cn&productId=1502435&mlfb=5SL7440-3RC","alternativesUrl":"https://aoctrl.com/api/mcp/products/5SL7440-3RC/alternatives.json"},"ai":{"faq":[{"question":"Where can I buy the 5SL7440-3RC and get a price?","answer":"This part is sourced and quoted to order against an RFQ through independent distribution. Availability and current pricing are confirmed at quote time — submit an RFQ for a firm price and lead time."},{"question":"What does the K characteristic mean on this breaker?","answer":"The K characteristic provides a magnetic trip threshold between B and C curves — typically 8 to 12 times the rated current — making it suitable for motor and transformer loads that draw high inrush on startup without nuisance tripping."},{"question":"What is the breaking capacity of the 5SL7440-3RC?","answer":"The 5SL7440-3RC has a 15 kA breaking capacity, meaning it can safely interrupt a fault current up to 15,000 amps at its rated voltage."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"matrix-langgraph","citationUrl":"https://aoctrl.com/siemens/5SL7440-3RC","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/5SL7440-3RC 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}}