{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"5SN6440-8CN","brand":"Siemens","brandSlug":"siemens","productSlug":"5SN6440-8CN","canonicalUrl":"https://aoctrl.com/siemens/5SN6440-8CN","factsUrl":"https://aoctrl.com/api/mcp/products/5SN6440-8CN","rawCanonicalId":null},"summary":{"shortDescription":"Siemens SENTRON 5SN series, miniature circuit breaker, 4-pole, D tripping characteristic, 40 A rated current, 6 kA breaking capacity at 400 V AC, order code 5SN6440-8CN.","salesMarkdown":"## Rated for motor and high-inrush loads The 76 mm depth plus 70 mm installation depth means it clears most shallow enclosures; check your gland-plate clearance if the panel is under 100 mm deep. Terminal capacity accepts 0.75 to 25 mm² solid or stranded, with a tightening torque of 2.5 to 3 N·m — no special crimp tool needed for the larger wire sizes. Mounting position is any, so vertical busbar or horizontal feed both work. IP20 with connected conductors is the usual for a panelboard device; no washdown rating, so keep it inside the enclosure.","metaTitle":"Siemens 5SN6440-8CN SENTRON MCB, 4P D 40A, 6kA","metaDescription":"Siemens 5SN6440-8CN SENTRON miniature circuit breaker, 4-pole, D-curve, 40 A, 6 kA breaking capacity per EN 60898, 400 V AC. Current lifecycle stage. Available to order.","metaKeywords":null},"attributes":{"series":null,"packageCase":null,"mountingType":null,"rohsStatus":null,"productStatus":null,"categoryPath":["4-Pole MCB (DIN Rail)"],"specifications":{"Depth":"76 mm","Solid":"0.75 ... 25 mm²","Width":"72 mm","title":"5SN6440-8CN","Height":"90 mm","Sealable":"Yes","Stranded":"0.75 ... 25 mm²","Rated Value":"50 Hz","description":"Circuit breaker 400V, 6kA, 4-pole, D, 40A","Halogen-Free":"Yes","Silicon-Free":"Yes","During Storage":"-40 ... +75 °C","Number of poles":"4","Type of voltage":"AC","lifecycle_stage":"current","Mounting position":"any","Installation depth":"70 mm","Product brand name":"SENTRON","Ambient temperature":"-25 ... +45 °C","Product designation":"Miniature circuit breaker","Protection class IP":"IP20, with connected conductors","Overvoltage category":"3","Design of the product":"Miniature circuit breaker 5SN","Number of width units":"4","Number of poles / Note":"4P","acc. to DIN EN 61346-2":"F","acc. to DIN EN 81346-2":"F","circuit-breaker / Design":"5SN6CN","Current / at AC / rated value":"40 A","Tripping characteristic class":"D","at DC / rated value / maximum":"60 V","acc. to EN 60898 / rated value":"6 kA","Product feature / Touch protection":"Yes","Supply voltage / at AC / rated value":"400 V","Influence of the surrounding temperature":"Periodically +55°C, max. 95% humidity","Vibration resistance / acc. to IEC 60068-2-6":"50 m/s² at 25 to 150 Hz","with multi-phase operation / at AC / maximum":"440 V","Tightening torque / with screw-type terminals":"2.5 ... 3 N·m","Product function / neutral conductor switching":"No","with multi-phase operation / at AC / rated value":"440 V"}},"commercial":{"minOrderQty":null,"leadTime":null,"referencePrice":null,"stockQuantity":0,"priceTiers":null},"links":{"datasheetUrl":"https://cdn.aoctrl.com/2535108745882f122caa31d0d54d4806.pdf","sourceUrl":"https://support.industry.siemens.com/webbackend/api/ProductSupport/TechnicalData?language=en&region=cn&productId=225015&mlfb=5SN6440-8CN"},"ai":{"faq":[{"question":"What does the D tripping characteristic mean for this 40 A breaker?","answer":"The D curve (magnetic trip at 10–14× rated current) is designed for loads with high inrush, such as motors, transformers, and discharge lighting. It will pass a starting surge that would trip a B or C curve, while still clearing a hard short circuit within the 6 kA rating."},{"question":"What wire sizes fit the terminals on the 5SN6440-8CN?","answer":"The screw terminals accept 0.75 to 25 mm² solid or stranded copper, with a recommended torque of 2.5 to 3 N·m."},{"question":"Where can I buy the 5SN6440-8CN and how is it quoted?","answer":"This part is sourced and quoted to order against an RFQ through independent industrial distribution. Availability and current pricing are confirmed at the time of quotation — no stock or price figures are published here."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"icboms-matrix-langgraph","citationUrl":"https://aoctrl.com/siemens/5SN6440-8CN","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/5SN6440-8CN 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}}