{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"5SY8440-8","brand":"Siemens","brandSlug":"siemens","productSlug":"5SY8440-8","canonicalUrl":"https://aoctrl.com/siemens/5SY8440-8","factsUrl":"https://aoctrl.com/api/mcp/products/5SY8440-8","rawCanonicalId":null},"summary":{"shortDescription":"Siemens SENTRON 5SY8440-8, 4-pole miniature circuit breaker, D tripping characteristic, 25 kA IEC 60947-2, 5 kA UL 1077, 4 MWU, IP20.","salesMarkdown":"## What the D-curve and breaking capacities mean for your panel Under UL 1077 the same part carries a 5 kA interrupting rating, which is the number a panel builder in a North American spec needs for the SCCR label. For DC circuits it's rated 15 kA at 60 V, covering battery-backed control buses and solar combiner boxes. The 5SY8440-8 occupies 4 modular width units (72 mm) on a standard DIN rail, with a depth of 76 mm and height of 90 mm — the 70 mm installation depth leaves clearance behind a standard 120 mm deep enclosure gland plate. ## Environmental limits and derating Ambient temperature range spans -40 °C to 75 °C, but the breaker's thermal-magnetic trip curve is influenced by surrounding temperature: relative humidity must be derated above 55 °C — max 95% RH up to 55 °C, then 55% RH up to 70 °C, and 35% RH up to the 75 °C ceiling. Vibration resistance per IEC 60068-2-6 is ±1 mm at 5 to 25 Hz and 50 m/s² at 25 to 150 Hz, which covers typical industrial panel vibration from nearby motors and conveyors.","metaTitle":"Siemens 5SY8440-8 SENTRON MCB, 4P, D-Curve, 25 kA IEC","metaDescription":"Siemens 5SY8440-8 SENTRON 4-pole miniature circuit breaker, D tripping characteristic, 25 kA per IEC 60947-2, 5 kA per UL 1077. Current lifecycle stage. Quoted to order against RFQ","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","Standard":"IEC / EN 60947-2 / UL1077","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":"400 V","at DC rated value":"60 V","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","Combined Terminal Bottom":"Yes","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":"25 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 W"}},"commercial":{"minOrderQty":null,"leadTime":null,"referencePrice":null,"priceTiers":null},"links":{"datasheetUrl":"https://cdn.aoctrl.com/48c17fa35bb269b9b080e95899a87c4d.pdf","sourceUrl":"https://support.industry.siemens.com/webbackend/api/ProductSupport/TechnicalData?language=en&region=cn&productId=57506&mlfb=5SY8440-8","alternativesUrl":"https://aoctrl.com/api/mcp/products/5SY8440-8/alternatives.json"},"ai":{"faq":[{"question":"What compliance documentation does Siemens provide for 5SY8440-8?","answer":"The part carries IEC / EN 60947-2 and UL 1077 certifications, with pollution degree 3 and overvoltage category III. Construction is halogen-free and silicon-free. Standard documentation includes the declaration of conformity, UL recognition file, and material compliance declarations (RoHS/REACH) — all available through the Siemens Industry Online Support portal."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"matrix-langgraph","citationUrl":"https://aoctrl.com/siemens/5SY8440-8","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/5SY8440-8 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}}