{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"5SY4640-7CV","brand":"Siemens","brandSlug":"siemens","productSlug":"5SY4640-7CV","canonicalUrl":"https://aoctrl.com/siemens/5SY4640-7CV","factsUrl":"https://aoctrl.com/api/mcp/products/5SY4640-7CV","rawCanonicalId":null},"summary":{"shortDescription":"Siemens 5SY series, MCB, Icu=15kA at 400V, 3P+N, C-curve 40A, order code 5SY4640-7CV.","salesMarkdown":"The Siemens 5SY4640-7CV is a 3P+N miniature circuit breaker rated for 40 A with a C-trip curve, breaking up to 15 kA at 400 V. The C-curve (5–10× In) is the standard choice for general-purpose distribution circuits feeding motor starters, contactor coils, and small transformers where moderate inrush is expected — it rides out the magnetizing surge without nuisance tripping on a pump or compressor start. ## What the ratings mean for fit The 15 kA Icu at 400 V is the ultimate short-circuit breaking capacity — the breaker can safely interrupt a fault current up to that level once and still be functional afterward. In a 400 V three-phase panel with a transformer rating that can deliver fault current in that range, this MCB provides adequate protection without needing an upstream current-limiting fuse. The 3P+N configuration switches all three phases and switches the neutral, which is required in some regional wiring codes (e.g., UK, Australia) where the neutral is not considered a solidly-grounded conductor. ## Panel integration Snap-on mounting to a standard 35 mm DIN rail. The 3P+N width occupies four modular spaces (4 x 18 mm). Busbar comb connections are compatible with the Siemens 5SY busbar system for distributing the incoming supply across multiple MCBs in a sub-distribution board.","metaTitle":"Siemens 5SY4640-7CV MCB, 15kA 400V 3P+N C40","metaDescription":"Siemens 5SY4640-7CV miniature circuit breaker, 15kA Icu at 400V, 3P+N, C-curve 40A. Current lifecycle stage. Available to order against RFQ.","metaKeywords":null},"attributes":{"series":null,"packageCase":null,"mountingType":null,"rohsStatus":null,"productStatus":null,"categoryPath":["Miniature Circuit Breakers (MCB)"],"specifications":{"title":"5SY4640-7CV","description":"MCB Icu=15KA 400V 3P+N C40","lifecycle_stage":"current"}},"commercial":{"minOrderQty":null,"leadTime":null,"referencePrice":null,"stockQuantity":0,"priceTiers":null},"links":{"datasheetUrl":"https://cdn.aoctrl.com/64303d69e8a530fda112b00f52cefdf7.pdf","sourceUrl":"https://support.industry.siemens.com/webbackend/api/ProductSupport/TechnicalData?language=en&region=cn&productId=1531708&mlfb=5SY4640-7CV"},"ai":{"faq":[{"question":"Where can I buy 5SY4640-7CV and how do I get a price?","answer":"The 5SY4640-7CV 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 is 5SY4640-7CV's listed description?","answer":"The description is MCB Icu=15kA 400V 3P+N C40, meaning a 40 A, C-curve miniature circuit breaker with a 15 kA breaking capacity at 400 V, three poles plus switched neutral."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"icboms-matrix-langgraph","citationUrl":"https://aoctrl.com/siemens/5SY4640-7CV","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/5SY4640-7CV 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}}