{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"5SY7640-8","brand":"Siemens","brandSlug":"siemens","productSlug":"5SY7640-8","canonicalUrl":"https://aoctrl.com/siemens/5SY7640-8","factsUrl":"https://aoctrl.com/api/mcp/products/5SY7640-8","rawCanonicalId":null},"summary":{"shortDescription":"Siemens SENTRON 5SY7640-8, 4-pole (3P+N) miniature circuit breaker, D tripping characteristic, 40 A at 35 °C, 400 V AC, 15 kA (EN 60898) / 20 kA (IEC 60947-2), 4 MW, IP20.","salesMarkdown":"The Siemens 5SY7640-8 is a 4-pole (3P+N) SENTRON miniature circuit breaker with a D tripping characteristic, rated 40 A at 35 °C and 400 V AC. That D-curve means it's built for loads with high inrush — motor starters, transformers, discharge lighting — where the magnetic trip holds off until 10–20× rated current, then clears fast. The 40 A rating holds at 35 °C ambient. Above that, the thermal element derates: 38.08 A at 40 °C, 37.08 A at 45 °C, 36.08 A at 50 °C, 35 A at 55 °C, and 33.92 A at 60 °C. If the panel runs hot — say 50 °C inside a sealed enclosure — the breaker's effective continuous current drops to 36.08 A. The operating range spans -40 °C to 75 °C, with humidity limits of 95% up to 55 °C, 55% up to 70 °C, and 35% up to 75 °C. ## Integration notes Position of the supply cord is any, which simplifies panel layout when the feed comes from an unexpected side. The sealable feature (tamper-evident cover over the toggle) is useful for installations requiring lockout-tagout or anti-tamper compliance. Touch protection is built into the terminal design.","metaTitle":"Siemens 5SY7640-8 SENTRON MCB, 4P, D-curve, 40 A, 15 kA","metaDescription":"Siemens 5SY7640-8 SENTRON miniature circuit breaker, 4-pole (3P+N), D tripping characteristic, 40 A at 35 °C, 15 kA per EN 60898, 20 kA per IEC 60947-2, 400 V AC. Active production","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","Number Of Poles":"4","Type Of Voltage":"AC","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":"400 V","protection class IP":"IP20, with connected conductors","Overvoltage Category":"III","Combined Terminal Top":"Yes","Number Of Poles / Note":"3P+N","acc. to DIN EN 61346-2":"F","at 35 °C / rated value":"40 A","at 40 °C / rated value":"38.08 A","at 45 °C / rated value":"37.08 A","at 50 °C / rated value":"36.08 A","at 55 °C / rated value":"35 A","at 60 °C / rated value":"33.92 A","Combined Terminal Bottom":"Yes","Suitability For Operation":"Mechanical engineering / industry","Number Of Modular Width Units":"4","Tripping Characteristic Class":"D","acc. to EN 60898 / rated value":"15 kA","Position / Of Power Supply Cord":"Any","acc. to IEC 60947-2 / rated value":"20 kA","Product Feature / Touch Protection":"Yes","Supply Voltage Frequency / Rated Value":"50/60 Hz","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","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 Function / Neutral Conductor Switching":"Yes","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 (Operating 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=220073&mlfb=5SY7640-8","alternativesUrl":"https://aoctrl.com/api/mcp/products/5SY7640-8/alternatives.json"},"ai":{"faq":[{"question":"What is the closest functional second-source to 5SY7640-8?","answer":"The 5SY7140-8CC is the closest functional peer: same 4-pole D-curve, 40 A rating, 15/20 kA breaking capacities, and 4-MW DIN footprint. The suffix difference may reflect regional cataloging or minor terminal variation, but both are current-production Siemens SENTRON parts and physically interchangeable in the same panel cutout."},{"question":"Will 5SY7640-8 drop into a panel specified around 5SY7140-8CC without rewiring?","answer":"Yes — same 4-pole (3P+N) configuration, same 4-modular-width (72 mm) footprint, same D-curve and 40 A rating. The busbar and DIN-rail mounting are identical. No rewiring needed."},{"question":"What compliance documentation does Siemens provide for 5SY7640-8?","answer":"The breaker carries EN 60898 (15 kA) and IEC 60947-2 (20 kA) ratings, overvoltage category III, pollution degree 3, and IP20 finger-safe terminals. It is halogen-free and silicon-free. Standard Siemens declarations of conformity (CE, UKCA) and the manufacturer's test certificates are available on request."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"matrix-langgraph","citationUrl":"https://aoctrl.com/siemens/5SY7640-8","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/5SY7640-8 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}}