{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"5SY4540-6","brand":"Siemens","brandSlug":"siemens","productSlug":"5SY4540-6","canonicalUrl":"https://aoctrl.com/siemens/5SY4540-6","factsUrl":"https://aoctrl.com/api/mcp/products/5SY4540-6","rawCanonicalId":null},"summary":{"shortDescription":"Siemens SENTRON 5SY4 series, miniature circuit breaker, 2-pole (1P+N), 40 A, B-curve, 10 kA (EN 60898) / 15 kA (IEC 60947-2), 230 V AC, IP20, quick assembly system, halogen-free, silicon-free, sealable.","salesMarkdown":"The Siemens 5SY4540-6 is a SENTRON miniature circuit breaker (MCB) rated for 40 A at 230 V AC, with a B tripping characteristic and 2 poles configured as 1P+N. It's built for mechanical engineering and industrial panel environments, where the B-curve handles resistive and light inductive loads without nuisance trips from inrush. That's the difference between protecting a sub-distribution board and a machine control cabinet. Halogen-free and silicon-free construction (cites:,) means it won't outgas corrosive compounds in a sealed enclosure — relevant for wind-turbine nacelle cabinets where condensation cycles are common. That's a good match for resistive loads (heaters, lighting) and general-purpose circuits where you don't want the breaker to see motor inrush and drop a line. If your load has a high starting surge, a C-curve sibling would be the better call. Overvoltage category III means it's rated for fixed-installation distribution panels, not just socket-outlet circuits. Storage range extends to -40 to +75 °C, which handles shipping through cold climates.","metaTitle":"Siemens 5SY4540-6 SENTRON MCB, 40 A, 2-pole, B-curve, 10 kA","metaDescription":"Siemens 5SY4540-6 SENTRON miniature circuit breaker, 40 A, 2-pole (1P+N), B-curve, 10 kA (EN 60898), 15 kA (IEC 60947-2). Quoted to order against an RFQ.","metaKeywords":null},"attributes":{"series":null,"packageCase":null,"mountingType":null,"rohsStatus":null,"productStatus":"Active","categoryPath":["1-Pole MCB (DIN Rail)"],"specifications":{"Depth":"76 mm","Solid":"0.75 ... 35 mm²","Width":"36 mm","title":"5SY4540-6","Height":"90 mm","Sealable":"Yes","Stranded":"0.75 ... 35 mm²","Rated Value":"50/60 Hz","description":"Miniature circuit breaker 230 V 10kA, 1+N-pole, B, 40A, D=70 mm","Halogen-Free":"Yes","Silicon-Free":"Yes","Mounting type":"Quick assembly system","During Storage":"-40 ... +75 °C","Number of poles":"2","Type of voltage":"AC","lifecycle_stage":"current","Mounting position":"any","Installation depth":"70 mm","Product brand name":"SENTRON","Ambient temperature":"-40 ... +70 °C","Product designation":"Miniature circuit breaker","Protection class IP":"IP20, with connected conductors","at AC / rated value":"230 V","Overvoltage category":"III","Combined Terminal Top":"Yes","Energy limiting class":"3","Number of width units":"2","Number of poles / Note":"1P+N","acc. to DIN EN 61346-2":"F","acc. to DIN EN 81346-2":"F","Combined Terminal Bottom":"Yes","circuit-breaker / Design":"5SY4","Suitability for operation":"Mechanical engineering / industry","Current / at AC / rated value":"40 A","Tripping characteristic class":"B","at DC / rated value / maximum":"72 V","acc. to EN 60898 / rated value":"10 kA","Position / of power supply cord":"Any","acc. to IEC 60947-2 / rated value":"15 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","at AC / acc. to UL 1077 and CSA C22.2 No.235":"5 kA","Tightening torque / with screw-type terminals":"2.5 ... 3.5 N·m","Product function / neutral conductor switching":"Yes","with single-phase operation / at AC / rated value":"250 V","Mechanical service life (switching cycles) / typical":"10 000","Tightening torque [lbf·in] / with screw-type terminals":"22 ... 31 lbf·in","AWG number / as coded connectable conductor cross section":"18 ... 4"}},"commercial":{"minOrderQty":null,"leadTime":null,"referencePrice":null,"stockQuantity":0,"priceTiers":null},"links":{"datasheetUrl":"https://cdn.aoctrl.com/2ebf107f3f1a13b9fc4a3b4ea8bba1cb.pdf","sourceUrl":"https://support.industry.siemens.com/webbackend/api/ProductSupport/TechnicalData?language=en&region=cn&productId=534414&mlfb=5SY4540-6"},"ai":{"faq":[{"question":"Where can I buy 5SY4540-6?","answer":"Sourced and quoted to order against an RFQ through independent distribution. Availability and current pricing are confirmed at quote time."},{"question":"What is 5SY4540-6's depth and conductor range?","answer":"Depth is 76 mm; installation depth is 70 mm. Solid and stranded conductors from 0.75 to 35 mm² fit the combined top and bottom terminals."},{"question":"How does 5SY4540-6 compare to 5SY6008-7?","answer":"The 5SY6008-7 is a higher-current (63 A) C-curve MCB in the same SENTRON 5SY family. The 5SY4540-6 is a 40 A B-curve unit. Both share the same 36 mm width and quick-assembly DIN mount, but the B-curve trips at 3–5× rated current versus the C-curve's 5–10×. If your circuit needs a 40 A B-curve, the 5SY4540-6 is the direct fit; the 5SY6008-7 would be a different rating and characteristic."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"icboms-matrix-langgraph","citationUrl":"https://aoctrl.com/siemens/5SY4540-6","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/5SY4540-6 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}}