{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"5SY8450-8","brand":"Siemens","brandSlug":"siemens","productSlug":"5SY8450-8","canonicalUrl":"https://aoctrl.com/siemens/5SY8450-8","factsUrl":"https://aoctrl.com/api/mcp/products/5SY8450-8","rawCanonicalId":null},"summary":{"shortDescription":"Siemens SENTRON 5SY8450-8, 4-pole D-curve miniature circuit breaker, 50 A rated at 45 °C, 20 kA breaking capacity per IEC 60947-2, 4 modular width units.","salesMarkdown":"The Siemens 5SY8450-8 is a SENTRON 4-pole miniature circuit breaker with a D tripping characteristic, rated 50 A at 45 °C and 48.95 A at 50 °C. The 20 kA breaking capacity per IEC 60947-2 at 440 V AC and 15 kA at 72 V DC tells you it can safely interrupt a bolted fault up to that level without cascading to upstream protective devices. For a panel feeding industrial machinery, that's the coordination headroom you need. ## Integration and installation constraints Mounting position is any orientation. The fastening method is a quick-assembly system; combined terminals at both top and bottom accept the incoming and outgoing conductors. The neutral conductor is not switched, so this is a 4-pole breaker with three protected phases and a solid neutral bar. Sealable, halogen-free, silicon-free — relevant for clean-room or food-bev installations where outgassing or tamper evidence matters. Marked as current production — no phase-out or last-time-buy notice on record. The 5SY8450-8 is a standard catalog line within the SENTRON family, suited for mechanical engineering and industry applications.","metaTitle":"Siemens 5SY8450-8 SENTRON MCB, D-Curve 50A 4P, 20kA","metaDescription":"Siemens 5SY8450-8 SENTRON miniature circuit breaker, 4-pole D-curve 50 A, 20 kA breaking capacity per IEC 60947-2. Current production, sourced to order. RFQ for availability.","metaKeywords":null},"attributes":{"series":null,"packageCase":null,"mountingType":null,"rohsStatus":null,"productStatus":"Active","categoryPath":["Miniature Circuit Breakers (MCB)"],"specifications":{"Depth":"76 mm","Width":"72 mm","Height":"90 mm","Maximum":"75 °C","Minimum":"-40 °C","Sealable":"Yes","Halogen-Free":"Yes","Silicon-Free":"Yes","Design Of Pole":"4P","Number Of Poles":"4","lifecycle_stage":"current","Fastening Method":"Quick assembly system","Mounting Position":"any","at AC rated value":"50 A","Installation Depth":"70 mm","Product Brand Name":"SENTRON","Degree Of Pollution":"3","Product Designation":"Miniature circuit breaker","protection class IP":"IP20, with connected conductors","Overvoltage Category":"III","Combined Terminal Top":"Yes","at 45 °C rated value":"50 A","at 50 °C rated value":"48.95 A","at 55 °C rated value":"47.85 A","according to EN 61346-2":"F","Combined Terminal Bottom":"Yes","according to IEC 81346-2":"F","Suitability For Operation":"Mechanical engineering / industry","Neutral Conductor Switching":"No","Number Of Modular Width Units":"4","Position Of Power Supply Cord":"Any","Tripping Characteristic Class":"D","according to IEC 60947-2 rated value":"20 kA","Influence Of The Surrounding Temperature":"max. 95% to 55°C, max. 55% to 70°C, max. 35% to 75°C","Type Of Voltage Of The Operating Voltage":"AC","at DC according to IEC 60947-2 rated value":"15 kA","Value Range Of The Supply Voltage Frequency":"50/60 Hz","operating voltage at DC rated value maximum":"72 V","with multi-phase operation at AC rated value":"440 V","with single-phase operation at AC rated value":"440 V","at AC according to UL 1077 and CSA C22.2 No.235":"5 kA","vibration resistance according to IEC 60068-2-6":"±1mm at 5 to 25Hz; 50m/s² at 25 to 150Hz","Mechanical Service Life (Operating Cycles) Typical":"10 000","Product Extension Installable Supplementary Devices":"Yes","supply voltage with single-phase operation at AC rated value":"230 V","power loss [W] for rated value of the current at AC in hot operating state per pole":"3.7 W"}},"commercial":{"minOrderQty":null,"leadTime":null,"referencePrice":null,"priceTiers":null},"links":{"datasheetUrl":"https://cdn.aoctrl.com/1163bd04533beb0a41e2cddf736c3517.pdf","sourceUrl":"https://support.industry.siemens.com/webbackend/api/ProductSupport/TechnicalData?language=en&region=cn&productId=33320&mlfb=5SY8450-8","alternativesUrl":"https://aoctrl.com/api/mcp/products/5SY8450-8/alternatives.json"},"ai":{"faq":[{"question":"Will 5SY8450-8 drop into a panel specified around 5SY4304-7CV without rewiring?","answer":"The 5SY8450-8 is a 4-pole D-curve 50 A breaker occupying 4 MW; the 5SY4304-7CV is a different pole/current/curve variant. A direct drop-in depends on whether the existing panel schedule and wiring match 50 A, 4-pole, D-curve. Verify the BOM line ratings before substituting."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"matrix-langgraph","citationUrl":"https://aoctrl.com/siemens/5SY8450-8","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/5SY8450-8 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}}