{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"5SY4420-8CV","brand":"Siemens","brandSlug":"siemens","productSlug":"5SY4420-8CV","canonicalUrl":"https://aoctrl.com/siemens/5SY4420-8CV","factsUrl":"https://aoctrl.com/api/mcp/products/5SY4420-8CV","rawCanonicalId":null},"summary":{"shortDescription":"Siemens 5SY4420-8CV, MCB, Icu=15kA at 400V, 4-pole, D20 curve.","salesMarkdown":"The Siemens 5SY4420-8CV is a 4-pole miniature circuit breaker rated for a 20 A D-curve trip characteristic, with a 15 kA breaking capacity at 400 V. The D-curve means it tolerates the high inrush of motor loads or transformers without nuisance tripping — the magnetic trip threshold sits around 10–20× rated current, so it's a fit for inductive circuits where a B- or C-curve would drop out on startup. The 15 kA Icu at 400 V gives enough fault-current headroom for most industrial panelboards tied to a transformer secondary or a generator bus. The 4-pole D20 configuration covers three-phase plus neutral switching, common in European-style distribution boards or machine control panels where the neutral needs overcurrent protection. The 15 kA SCCR at 400 V means it can be installed downstream of a larger main breaker without worrying about the fault current exceeding the breaker's rating — coordination stays clean.","metaTitle":"5SY4420-8CV MCB, Icu=15kA 400V 4P D20, current lifecycle","metaDescription":"5SY4420-8CV MCB by Siemens, Icu=15kA at 400V, 4-pole D20 curve. Current lifecycle stage. Available to order against RFQ via independent distribution.","metaKeywords":null},"attributes":{"series":null,"packageCase":null,"mountingType":null,"rohsStatus":null,"productStatus":null,"categoryPath":["Miniature Circuit Breakers (MCB)"],"specifications":{"title":"5SY4420-8CV","description":"MCB Icu=15KA 400V 4P D20","lifecycle_stage":"current"}},"commercial":{"minOrderQty":null,"leadTime":null,"referencePrice":null,"stockQuantity":0,"priceTiers":null},"links":{"datasheetUrl":"https://cdn.aoctrl.com/b4fe4a87a095a5a1cdb834b29e0d4c0d.pdf","sourceUrl":"https://support.industry.siemens.com/webbackend/api/ProductSupport/TechnicalData?language=en&region=cn&productId=1531631&mlfb=5SY4420-8CV"},"ai":{"faq":[{"question":"What is 5SY4420-8CV's rated breaking capacity?","answer":"The 5SY4420-8CV has a rated ultimate breaking capacity (Icu) of 15 kA at 400 V."},{"question":"Where can I buy 5SY4420-8CV?","answer":"This part is sourced and quoted to order against an RFQ through independent distribution; availability and current pricing are confirmed at quote time."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"icboms-matrix-langgraph","citationUrl":"https://aoctrl.com/siemens/5SY4420-8CV","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/5SY4420-8CV 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}}