{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"5SY4240-7CV","brand":"Siemens","brandSlug":"siemens","productSlug":"5SY4240-7CV","canonicalUrl":"https://aoctrl.com/siemens/5SY4240-7CV","factsUrl":"https://aoctrl.com/api/mcp/products/5SY4240-7CV","rawCanonicalId":null},"summary":{"shortDescription":"Siemens 5SY4240-7CV, 2-pole C40 miniature circuit breaker, 15 kA breaking capacity at 400 V AC, current lifecycle stage.","salesMarkdown":"The Siemens 5SY4240-7CV is a 2-pole miniature circuit breaker (MCB) with a C-curve trip characteristic rated at 40 A. Its interrupting capacity is 15 kA at 400 V AC, which means it can safely clear a bolted fault up to that level without welding its contacts or rupturing the arc chamber — a spec that matters when coordinating downstream branch protection in a panel. The C-curve (trip threshold 5–10× In) suits it for mixed resistive and moderate inductive loads where inrush isn't extreme — think motor control circuits, lighting banks, or general distribution subfeeds. The 2-pole form factor snaps onto standard DIN rail and occupies two module widths in the enclosure. ## What the ratings mean for fit The 15 kA breaking capacity at 400 V AC governs selective coordination. The 40 A C-curve rating means the thermal-magnetic trip holds continuous current up to 40 A and trips instantaneously between 200 A and 400 A. For a 40 A feeder, that's standard; for a motor circuit drawing 38 A full-load, check that the starting inrush (typically 6–8× FLA for a brief cycle) stays under the magnetic trip threshold to avoid nuisance tripping on startup.","metaTitle":"Siemens 5SY4240-7CV MCB, 2P C40, 15kA at 400V","metaDescription":"Siemens 5SY4240-7CV miniature circuit breaker, 2-pole C-curve 40A, 15kA breaking capacity at 400V AC. Current lifecycle stage: active production. Sourced to order against RFQ.","metaKeywords":null},"attributes":{"series":null,"packageCase":null,"mountingType":null,"rohsStatus":null,"productStatus":null,"categoryPath":["2-Pole MCB (DIN Rail)"],"specifications":{"title":"5SY4240-7CV","description":"MCB Icu=15KA 400V 2P C40","lifecycle_stage":"current"}},"commercial":{"minOrderQty":null,"leadTime":null,"referencePrice":null,"stockQuantity":0,"priceTiers":null},"links":{"datasheetUrl":"https://cdn.aoctrl.com/832c387e85828618590ee4ee8ff495a7.pdf","sourceUrl":"https://support.industry.siemens.com/webbackend/api/ProductSupport/TechnicalData?language=en&region=cn&productId=1531564&mlfb=5SY4240-7CV"},"ai":{"faq":[{"question":"What is the breaking capacity of the 5SY4240-7CV?","answer":"The interrupting capacity is 15 kA at 400 V AC, as stated in the product description."},{"question":"What does the description 'MCB Icu=15kA 400V 2P C40' mean?","answer":"It means this is a miniature circuit breaker with a 15 kA ultimate breaking capacity (Icu) at 400 V AC, 2 poles, C-curve trip characteristic, rated 40 A."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"icboms-matrix-langgraph","citationUrl":"https://aoctrl.com/siemens/5SY4240-7CV","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/5SY4240-7CV when reusing this data. Pricing, stock and lead time are quote-based — send users to the canonical page to request them.","lastUpdated":"2026-08-11T15:51:03.652Z","lastPublished":"2026-08-11T15:51:03.652Z","indexable":true}}