{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"5SY8205-8","brand":"Siemens","brandSlug":"siemens","productSlug":"5SY8205-8","canonicalUrl":"https://aoctrl.com/siemens/5SY8205-8","factsUrl":"https://aoctrl.com/api/mcp/products/5SY8205-8","rawCanonicalId":null},"summary":{"shortDescription":"Siemens SENTRON 5SY8 series, miniature circuit breaker (MCB), 2-pole, D tripping characteristic, 0.5 A rated current, 70 kA breaking capacity at 400 V AC, IP20.","salesMarkdown":"## What the 70 kA SCCR means for your panel The Siemens 5SY8205-8 is a 2-pole SENTRON miniature circuit breaker with a D tripping characteristic, rated 0.5 A at 400 V AC. The D-curve (10–20× In magnetic trip) is deliberate: it rides out the inrush of a small transformer, solenoid bank, or motor starter without nuisance tripping, then clears fast on a hard fault. ## Thermal derating and environmental range The 0.5 A rating is at 45 °C ambient. At 50 °C it derates to 0.48 A, and at 55 °C to 0.47 A — a linear drop of about 4% per 5 °C step. The operating range spans -40 °C to 75 °C, with humidity limits of 95% at 55 °C, tapering to 35% at 75 °C. That wide thermal envelope suits unheated enclosures or outdoor cabinets in temperate to hot climates. Snap-on quick assembly system, mountable in any position. Touch protection is built in, so no additional finger-safe shrouds needed for the front panel. ## DC and UL ratings For DC circuits per IEC 60947-2, the breaking capacity is 15 kA. Under UL 1077 and CSA C22.2 No. 235 (supplementary protector recognition), it is rated 5 kA at 400 V AC. Vibration resistance per IEC 60068-2-6: ±1 mm at 5–25 Hz, 50 m/s² at 25–150 Hz. These ratings confirm it for industrial machinery panels that see moderate vibration from nearby drives or conveyors.","metaTitle":"Siemens 5SY8205-8 SENTRON MCB, 2P D 0.5A, 70kA","metaDescription":"Siemens 5SY8205-8 SENTRON 2-pole MCB, D-curve 0.5A, 70kA breaking capacity at 400V AC. Current production. Sourced to order. Request RFQ.","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","title":"5SY8205-8","Height":"90 mm","Maximum":"75 °C","Minimum":"-40 °C","Sealable":"Yes","description":"Miniature circuit breaker 400 V D=70 mm 25 kA according to EN 60947-2, 2P, D0.5","Halogen-Free":"Yes","Silicon-Free":"Yes","Number Of Poles":"2","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":"2P","acc. to DIN EN 61346-2":"F","at 45 °C / rated value":"0.5 A","at 50 °C / rated value":"0.48 A","at 55 °C / rated value":"0.47 A","Combined Terminal Bottom":"Yes","Suitability For Operation":"Mechanical engineering / industry","Number Of Modular Width Units":"2","Tripping Characteristic Class":"D","Position / Of Power Supply Cord":"Any","acc. to IEC 60947-2 / rated value":"70 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":"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 (Operating Cycles) / Typical":"10 000"}},"commercial":{"minOrderQty":null,"leadTime":null,"referencePrice":null,"stockQuantity":0,"priceTiers":null},"links":{"datasheetUrl":"https://cdn.aoctrl.com/64e850cff15012938c70ac509e5d3c55.pdf","sourceUrl":"https://support.industry.siemens.com/webbackend/api/ProductSupport/TechnicalData?language=en&region=cn&productId=1604&mlfb=5SY8205-8"},"ai":{"faq":[{"question":"What does the D-curve mean on this 0.5 A breaker?","answer":"The D tripping characteristic (magnetic trip at 10–20× In) means it tolerates the high inrush of small transformers, solenoid valves, or motor starters without nuisance tripping, while still clearing a hard short fast. For a 0.5 A rating, that inrush tolerance is useful on control transformers or relay coils."},{"question":"What is the breaking capacity of the 5SY8205-8?","answer":"70 kA at 400 V AC per IEC 60947-2. For DC circuits it is 15 kA, and under UL 1077 / CSA C22.2 No. 235 it is 5 kA at 400 V AC."},{"question":"Where can I buy the 5SY8205-8?","answer":"This part is sourced to order through our independent distribution channel. Availability and current pricing are confirmed at quote time against an RFQ — no stock or price figures are published here."},{"question":"Does the 5SY8205-8 have UL or CSA approval?","answer":"It carries a UL 1077 and CSA C22.2 No. 235 supplementary protector rating at 5 kA / 400 V AC. The primary IEC 60947-2 rating is 70 kA at 400 V AC."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"icboms-matrix-langgraph","citationUrl":"https://aoctrl.com/siemens/5SY8205-8","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/5SY8205-8 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}}