{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"5SY4320-8","brand":"Siemens","brandSlug":"siemens","productSlug":"5SY4320-8","canonicalUrl":"https://aoctrl.com/siemens/5SY4320-8","factsUrl":"https://aoctrl.com/api/mcp/products/5SY4320-8","rawCanonicalId":null},"summary":{"shortDescription":"Siemens SENTRON 5SY4320-8, 3-pole miniature circuit breaker, D tripping characteristic, 20 A rated at AC, 10 kA / 20 kA breaking capacity, 3 modular width units, DIN rail mount.","salesMarkdown":"## Breaking capacity and dual-standard certification The higher IEC 60947-2 figure applies when the breaker is used as a distribution or industrial circuit protector — the 20 kA SCCR gives headroom for fault currents in panelboard feeders without cascading upstream fuses. The 5SY4320-8 carries approvals under both the household-standard (EN 60898-1) and industrial-standard (IEC 60947-2 / UL1077) frameworks, so it can be specified in residential DBs or industrial MCCs without a change order. ## Temperature derating and panel integration At 35 °C ambient the breaker holds the full 20 A rating. The published derating table lets you calculate the real load limit inside a warm enclosure without guessing. Mounting position is any orientation. The quick-assembly system snaps onto the rail and the combined top/bottom terminals accept the busbar or ring-tongue feeder.","metaTitle":"Siemens 5SY4320-8 SENTRON MCB, 3-Pole D Curve 20 A","metaDescription":"Siemens 5SY4320-8 SENTRON 3-pole MCB, D-curve, 20 A rated, 10 kA (EN 60898) / 20 kA (IEC 60947-2) breaking capacity. Active production, sourced to order.","metaKeywords":null},"attributes":{"series":null,"packageCase":null,"mountingType":null,"rohsStatus":null,"productStatus":"Active","categoryPath":["3-Pole MCB (DIN Rail)"],"specifications":{"Depth":"76 mm","Width":"54 mm","title":"5SY4320-8","Height":"90 mm","Maximum":"75 °C","Minimum":"-40 °C","Sealable":"Yes","Standard":"IEC / EN 60898-1, IEC / EN 60947-2 / UL1077","description":"Miniature circuit breaker 400 V 10kA, 3-pole, D, 20 A, D=70 mm","Halogen-Free":"Yes","Silicon-Free":"Yes","Design Of Pole":"3P","Number Of Poles":"3","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","at AC / rated value":"20 A","protection class IP":"IP20, with connected conductors","Overvoltage Category":"III","Combined Terminal Top":"Yes","according to EN 61346-2":"F","at 35 °C / rated value":"20 A","at 40 °C / rated value":"19.04 A","at 45 °C / rated value":"18.54 A","at 50 °C / rated value":"18.04 A","at 55 °C / rated value":"17.5 A","at 60 °C / rated value":"16.96 A","Combined Terminal Bottom":"Yes","according to IEC 81346-2":"F","Suitability For Operation":"Mechanical engineering / industry","Number Of Modular Width Units":"3","Tripping Characteristic Class":"D","Position / Of Power Supply Cord":"Any","Product Feature / Touch Protection":"Yes","according to EN 60898 / rated value":"10 kA","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","Value Range / Of The Supply Voltage Frequency":"50/60 Hz","at DC / according to IEC 60947-2 / rated value":"15 kA","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","vibration resistance / according to IEC 60068-2-6":"±1mm at 5 to 25Hz; 50m/s² at 25 to 150Hz","with single-phase operation / at AC / rated value":"440 V","Mechanical Service Life (Switching Cycles) / Typical":"10 000"}},"commercial":{"minOrderQty":null,"leadTime":null,"referencePrice":"$25.40","stockQuantity":0,"priceTiers":null},"links":{"datasheetUrl":"https://cdn.aoctrl.com/37384a4439c3e887c8a21622ef799729.pdf","sourceUrl":"https://support.industry.siemens.com/webbackend/api/ProductSupport/TechnicalData?language=en&region=cn&productId=468076&mlfb=5SY4320-8"},"ai":{"faq":[],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"icboms-matrix-langgraph","citationUrl":"https://aoctrl.com/siemens/5SY4320-8","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/5SY4320-8 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}}