{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"5SL4340-8","brand":"Siemens","brandSlug":"siemens","productSlug":"5SL4340-8","canonicalUrl":"https://aoctrl.com/siemens/5SL4340-8","factsUrl":"https://aoctrl.com/api/mcp/products/5SL4340-8","rawCanonicalId":null},"summary":{"shortDescription":"Siemens SENTRON 5SL4340-8 miniature circuit breaker, 3-pole, D-curve, 40 A, 400 V AC, 10 kA breaking capacity per EN 60898 and IEC 60947-2.","salesMarkdown":"The Siemens 5SL4340-8 is a SENTRON miniature circuit breaker (MCB) — 3-pole, D-tripping characteristic, rated 40 A at 400 V AC, with a 10 kA breaking capacity certified to both EN 60898 and IEC 60947-2. That dual-standard rating means it covers residential/infrastructure panelboards (EN 60898) and industrial feeder circuits (IEC 60947-2) under one order code, simplifying your BOM for mixed-duty panels. D-curve tripping (10–20× In) is the right choice for transformer inrush, motor starting, or any load with a high short-duration surge — the magnetic trip holds off nuisance trips while still clearing a hard fault within the 10 kA SCCR. At 40 A this MCB handles a 15–20 kW three-phase motor or a lighting/distribution subfeed. Rated current derates with ambient temperature: 40 A at 30 °C, 37.89 A at 40 °C, 36.8 A at 45 °C, 34.47 A at 55 °C. In a warm enclosure (say 45 °C internal) the effective continuous rating drops to 36.8 A — size your upstream protection accordingly. IP20 with conductors connected — fine for enclosed panels, not for wet-area standalone use. Mounting position any, so it can be installed horizontally or vertically inside a cabinet without derating. Overvoltage category III (distribution-level), pollution degree 2 (normal industrial/ commercial environment). Sealable terminals available — required for utility-metering or revenue-grade panels where tamper evidence is mandatory. Mechanical life 10 000 switching cycles typical — adequate for a protection device that operates infrequently (fault clearing or manual isolation), not a daily-switched load-break device. ## Selectivity & Coordination Energy limitation class 3 means this MCB limits let-through energy enough to coordinate with downstream branch breakers in most residential and light-commercial panelboards. The 5SL4340-8 is a 3-pole device switching all phases — it breaks all three poles simultaneously on a fault on any phase, which is standard for three-phase subfeeds and motor circuits. Do not use it for single-phase branch protection unless you are comfortable with an unswitched neutral.","metaTitle":"Siemens 5SL4340-8 SENTRON MCB, 3P D 40A 10kA","metaDescription":"Siemens SENTRON 5SL4340-8 miniature circuit breaker, 3-pole, D-curve, 40 A rated at 400 V AC, 10 kA breaking capacity (EN 60898/IEC 60947-2). 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":"5SL4340-8","Height":"90 mm","Maximum":"75 °C","Minimum":"-40 °C","Sealable":"Yes","description":"Miniature circuit breaker 400 V 10kA, 3-pole, D, 40 A","Halogen-Free":"Yes","Silicon-Free":"Yes","Design Of Pole":"3P","Number Of Poles":"3","lifecycle_stage":"current","Mounting Position":"any","Installation Depth":"70 mm","Product Brand Name":"SENTRON","Degree Of Pollution":"2","Product Designation":"Miniature circuit breaker","at AC / rated value":"40 A","protection class IP":"IP20, with connected conductors","Overvoltage Category":"III","Energy Limitation Class":"3","according to EN 61346-2":"F","at 30 °C / rated value":"40 A","at 40 °C / rated value":"37.89 A","at 45 °C / rated value":"36.8 A","at 55 °C / rated value":"34.47 A","according to IEC 81346-2":"F","Suitability For Operation":"Residential buildings/infrastructure","Number Of Modular Width Units":"3","Tripping Characteristic Class":"D","at DC / rated value / maximum":"72 V","according to EN 60898 / rated value":"10 kA","supply voltage / at AC / rated value":"400 V","according to IEC 60947-2 / rated value":"10 kA","Type Of Voltage / Of The Operating Voltage":"AC","with multi-phase operation / at AC / maximum":"440 V","with multi-phase operation / at AC / rated value":"440 V","Mechanical Service Life (Switching Cycles) / Typical":"10 000"}},"commercial":{"minOrderQty":null,"leadTime":null,"referencePrice":null,"stockQuantity":0,"priceTiers":null},"links":{"datasheetUrl":"https://cdn.aoctrl.com/14bff235354d92c9f23a8ad09209f9ba.pdf","sourceUrl":"https://support.industry.siemens.com/webbackend/api/ProductSupport/TechnicalData?language=en&region=cn&productId=192748&mlfb=5SL4340-8"},"ai":{"faq":[{"question":"Will the 5SL4340-8 drop into a panel specified for the 5SL4363-7 without rewiring?","answer":"The 5SL4340-8 and 5SL4363-7 share the same SENTRON 5SL platform — same 3-pole DIN-rail footprint, same 54 mm width (3 MW). The deciding difference is the trip curve and rating: the 5SL4340-8 is a D-curve 40 A, while the 5SL4363-7 is a different curve/rating. If the panel was wired for a 3-pole 40 A D-curve, the 5SL4340-8 drops in without rewiring. Verify the original order code's rating and curve against your load before committing."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"icboms-matrix-langgraph","citationUrl":"https://aoctrl.com/siemens/5SL4340-8","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/5SL4340-8 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}}