{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"5SY8263-8","brand":"Siemens","brandSlug":"siemens","productSlug":"5SY8263-8","canonicalUrl":"https://aoctrl.com/siemens/5SY8263-8","factsUrl":"https://aoctrl.com/api/mcp/products/5SY8263-8","rawCanonicalId":null},"summary":{"shortDescription":"Siemens SENTRON 5SY8263-8 miniature circuit breaker, 2-pole, D tripping characteristic, 63 A rated current, 20 kA breaking capacity at 400 V AC per IEC 60947-2, IP20.","salesMarkdown":"## Siemens 5SY8263-8 — 63 A D-Curve MCB for High-Inrush Loads The Siemens 5SY8263-8 is a 2-pole SENTRON miniature circuit breaker rated 63 A with a D tripping characteristic, designed to handle the high inrush currents of motor starters, transformers, and welding equipment without nuisance tripping. Its 20 kA breaking capacity at 400 V AC per IEC 60947-2 means it can safely interrupt fault currents up to that level in industrial panel applications, providing adequate SCCR headroom for most distribution boards. The 15 kA DC rating per IEC 60947-2 covers DC-side protection in rectifier-fed circuits. Rated 63 A at 45 °C ambient, it derates to 61.05 A at 50 °C and 59.03 A at 55 °C — a thermal curve worth checking if the breaker sits in a warm enclosure alongside other heat-generating devices. ## Panel Fit & Environment The 36 mm width (2 modular units) and 76 mm depth fit standard DIN-rail enclosures; the 70 mm installation depth leaves clearance behind the rail for wiring. The -40 to 75 °C operating range covers unheated warehouses and roof-mounted cabinets.","metaTitle":"Siemens 5SY8263-8 SENTRON MCB, D Curve, 63 A, 2 Pole, 20 kA","metaDescription":"Siemens 5SY8263-8 SENTRON miniature circuit breaker, 63 A, 2-pole, D tripping characteristic, 20 kA breaking capacity per IEC 60947-2. Active production, sourced to order. Request","metaKeywords":null},"attributes":{"series":null,"packageCase":null,"mountingType":null,"rohsStatus":null,"productStatus":"Active","categoryPath":["2-Pole MCB (DIN Rail)"],"specifications":{"Depth":"76 mm","Width":"36 mm","Height":"90 mm","Maximum":"75 °C","Minimum":"-40 °C","Sealable":"Yes","Halogen-Free":"Yes","Silicon-Free":"Yes","Design Of Pole":"2P","Number Of Poles":"2","lifecycle_stage":"current","Fastening Method":"Quick assembly system","Mounting Position":"any","Installation Depth":"70 mm","Product Brand Name":"SENTRON","Degree Of Pollution":"3","Product Designation":"Miniature circuit breaker","acc. to IEC 81346-2":"F","at AC / rated value":"63 A","protection class IP":"IP20, with connected conductors","Overvoltage Category":"III","Combined Terminal Top":"Yes","acc. to DIN EN 61346-2":"F","at 45 °C / rated value":"63 A","at 50 °C / rated value":"61.05 A","at 55 °C / rated value":"59.03 A","Combined Terminal Bottom":"Yes","Suitability For Operation":"Mechanical engineering / industry","Number Of Modular Width Units":"2","Tripping Characteristic Class":"D","Position / Of Power Supply Cord":"Any","acc. to IEC 60947-2 / rated value":"20 kA","Product Feature / Touch Protection":"Yes","Influence Of The Surrounding Temperature":"max. 95% to 55°C, max. 55% to 70°C, max. 35% to 75°C","at DC / acc. to IEC 60947-2 / rated value":"15 kA","Type Of Voltage / Of The Operating Voltage":"AC","at AC / acc. to UL 1077 and CSA C22.2 No.235":"5 kA","vibration resistance / acc. to IEC 60068-2-6":"±1mm at 5 to 25Hz; 50m/s² at 25 to 150Hz","Product Component / Neutral Conductor Switching":"No","with multi-phase operation / at AC / rated value":"440 V","operating voltage / at DC / rated value / maximum":"72 V","with single-phase operation / at AC / rated value":"440 V","Mechanical Service Life (Switching Cycles) / Typical":"10 000"}},"commercial":{"minOrderQty":null,"leadTime":null,"referencePrice":null,"priceTiers":null},"links":{"datasheetUrl":null,"sourceUrl":"https://support.industry.siemens.com/webbackend/api/ProductSupport/TechnicalData?language=en&region=cn&productId=270201&mlfb=5SY8263-8","alternativesUrl":"https://aoctrl.com/api/mcp/products/5SY8263-8/alternatives.json"},"ai":{"faq":[{"question":"What is the breaking capacity of 5SY8263-8?","answer":"20 kA at 400 V AC per IEC 60947-2, and 15 kA at the DC rating per the same standard. Under UL 1077 it carries a 5 kA interrupting rating."},{"question":"Where can I buy 5SY8263-8?","answer":"Sourced and quoted to order against an RFQ through independent distribution channels. Availability and current pricing are confirmed at quote time."},{"question":"What compliance documentation is available for 5SY8263-8?","answer":"The breaker carries IEC 60947-2, UL 1077, and CSA C22.2 No. 235 certifications. It is halogen-free and silicon-free, and suitable for mechanical engineering and industrial applications."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"matrix-langgraph","citationUrl":"https://aoctrl.com/siemens/5SY8263-8","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/5SY8263-8 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}}