{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"5SY7240-8","brand":"Siemens","brandSlug":"siemens","productSlug":"5SY7240-8","canonicalUrl":"https://aoctrl.com/siemens/5SY7240-8","factsUrl":"https://aoctrl.com/api/mcp/products/5SY7240-8","rawCanonicalId":null},"summary":{"shortDescription":"Siemens SENTRON 5SY7240-8 miniature circuit breaker, 2-pole, 40 A, D tripping characteristic, 15 kA (EN 60898) / 20 kA (IEC 60947-2), 2 MW.","salesMarkdown":"The Siemens 5SY7240-8 is a 2-pole SENTRON miniature circuit breaker rated 40 A with a D tripping characteristic, designed to protect branch circuits against overcurrent and short circuits in industrial control panels and distribution boards. The D curve means it tolerates high inrush currents — typical for motor, transformer, or welding loads — without nuisance tripping, while still clearing faults at 15 kA per EN 60898 or 20 kA per IEC 60947-2. It snaps onto a DIN rail (2 modular width units, 36 mm wide) and mounts in any position, with a depth of 76 mm and an installation depth of 70 mm, so it fits standard enclosures without extra clearance. ## Ratings and derating — what they mean on the panel At 35 °C ambient the breaker carries the full 40 A; at 40 °C it derates to 37.56 A, at 50 °C to 34.96 A, and at 60 °C to 32.16 A — so if the panel runs hot, size the upstream protection for the derated value, not the nameplate. Certified to IEC/EN 60898-1, IEC/EN 60947-2, and UL 1077, with a halogen-free, silicon-free design. Compliance documentation (RoHS, REACH) is available with the shipment.","metaTitle":"Siemens 5SY7240-8 SENTRON MCB, 2P, 40 A, D Curve, 15 kA","metaDescription":"Siemens 5SY7240-8 SENTRON miniature circuit breaker, 2-pole, 40 A, D tripping characteristic, 15 kA (EN 60898) / 20 kA (IEC 60947-2). Current production. Quoted to order.","metaKeywords":null},"attributes":{"series":null,"packageCase":null,"mountingType":null,"rohsStatus":null,"productStatus":"Active","categoryPath":["2-Pole MCB (DIN Rail)"],"specifications":{"Depth":"76 mm","Width":"36 mm","Height":"90 mm","Maximum":"75 °C","Minimum":"-40 °C","Sealable":"Yes","Standard":"IEC / EN 60898-1, IEC / EN 60947-2 / UL1077","Halogen-Free":"Yes","Silicon-Free":"Yes","Design Of Pole":"2P","Number Of Poles":"2","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":"40 A","protection class IP":"IP20, with connected conductors","Overvoltage Category":"III","Combined Terminal Top":"Yes","acc. to DIN EN 61346-2":"F","at 35 °C / rated value":"40 A","at 40 °C / rated value":"37.56 A","at 45 °C / rated value":"36.28 A","at 50 °C / rated value":"34.96 A","at 55 °C / rated value":"33.6 A","at 60 °C / rated value":"32.16 A","Combined Terminal Bottom":"Yes","Suitability For Operation":"Mechanical engineering / industry","Number Of Modular Width Units":"2","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","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","Type Of Voltage / Of The Operating Voltage":"AC","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 Component / Neutral Conductor Switching":"No","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 (Switching 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=68181&mlfb=5SY7240-8","alternativesUrl":"https://aoctrl.com/api/mcp/products/5SY7240-8/alternatives.json"},"ai":{"faq":[{"question":"What is the breaking capacity of 5SY7240-8?","answer":"15 kA per EN 60898 and 20 kA per IEC 60947-2; at DC per IEC 60947-2 it is rated 15 kA."},{"question":"Will 5SY7240-8 drop into a panel that was specified around 5SY7206-7CC without rewiring?","answer":"Both are 2-pole SENTRON MCBs with the same 36 mm width and DIN-rail mount, so the footprint is identical — but the 5SY7240-8 is a 40 A D-curve, while the 5SY7206-7CC is a different rating/curve; verify the branch-circuit protection requirements before swapping."},{"question":"What compliance documentation does Siemens provide for 5SY7240-8?","answer":"The breaker carries IEC/EN 60898-1, IEC/EN 60947-2, and UL 1077 certifications, is halogen-free and silicon-free, and RoHS/REACH declarations are available with the shipment."},{"question":"How do I get current pricing and availability for 5SY7240-8?","answer":"Submit an RFQ — the part is sourced to order through independent distribution, and a current price and lead time will be confirmed at quote time."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"matrix-langgraph","citationUrl":"https://aoctrl.com/siemens/5SY7240-8","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/5SY7240-8 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}}