{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"5SY8208-7","brand":"Siemens","brandSlug":"siemens","productSlug":"5SY8208-7","canonicalUrl":"https://aoctrl.com/siemens/5SY8208-7","factsUrl":"https://aoctrl.com/api/mcp/products/5SY8208-7","rawCanonicalId":null},"summary":{"shortDescription":"Siemens SENTRON 5SY8208-7 miniature circuit breaker, 2-pole, C-trip characteristic, 40 kA breaking capacity per IEC 60947-2, 400 V AC rated, 36 mm wide, IP20.","salesMarkdown":"## What this MCB does on the line The Siemens SENTRON 5SY8208-7 is a 2-pole miniature circuit breaker with a C-trip characteristic, rated to clear 40 kA at 400 V AC per IEC 60947-2. The 40 kA interrupting rating tells you it can handle a hard fault without welding its contacts shut, which is what you need when the line's fed from a transformer with stiff source impedance. On the DC side it's rated 15 kA at 60 V, and it carries a UL 1077 supplementary protector listing at 5 kA for North American panels that don't need a full branch-circuit rated breaker. The 2-pole design switches both lines simultaneously with no neutral switching — straight hot-to-hot protection for single-phase or two-leg DC circuits. Width is 36 mm — that's 2 modular units on a standard DIN rail. Snap it onto the rail with the quick-assembly system; no tools needed to clip it in. Mount in any position, which helps when you're cramming gear into a tight gland plate or a swing-frame panel. IP20 with connected conductors — fine inside a locked panel, not for washdown zones. ## Environmental tolerance and compliance Humidity tolerance is spelled out in the spec — max 95% RH up to 55 °C, derating to 35% at 75 °C. That covers everything from a cold storage warehouse floor to a sun-baked panel roof in a southern mill. Halogen-free and silicon-free construction, which matters if the panel sits near sensitive electronics or in a plenum where off-gassing could be an issue. Vibration resistance per IEC 60068-2-6: ±1 mm displacement at 5 to 25 Hz, and 5 g acceleration at 25 to 150 Hz. That's enough to survive on a machine skid or near a reciprocating compressor without nuisance tripping. Designed to IEC / EN 60947-2 and UL 1077. The IEC 60947-2 rating at 40 kA is the primary spec for global panels; the UL 1077 listing at 5 kA lets it serve as a supplementary protector in North American equipment — not a branch-circuit rated breaker per UL 489, so check your local code if it's feeding a service entrance. The C-trip curve and 2-pole format match the footprint of the wider SENTRON 5SY family, so it swaps in without re-drilling the rail or re-looming the wiring.","metaTitle":"Siemens SENTRON 5SY8208-7 MCB, 2P, C-Curve, 40 kA IEC","metaDescription":"Siemens SENTRON 5SY8208-7 miniature circuit breaker, 2-pole, C-trip characteristic, 40 kA breaking capacity per IEC 60947-2. Active production. Quoted on request.","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":"5SY8208-7","Height":"90 mm","Maximum":"75 °C","Minimum":"-40 °C","Sealable":"Yes","Standard":"IEC / EN 60947-2 / UL1077","description":"Miniature circuit breaker 400 V D=70 mm 25 kA according to EN 60947-2, 2P, C8","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","at AC rated value":"400 V","at DC rated value":"60 V","Installation Depth":"70 mm","Product Brand Name":"SENTRON","Degree Of Pollution":"3","Product Designation":"Miniature circuit breaker","protection class IP":"IP20, with connected conductors","Overvoltage Category":"III","Combined Terminal Top":"Yes","Combined Terminal Bottom":"Yes","Suitability For Operation":"Mechanical engineering / industry","Neutral Conductor Switching":"No","Number Of Modular Width Units":"2","Position Of Power Supply Cord":"Any","Tripping Characteristic Class":"C","according to IEC 60947-2 rated value":"40 kA","Influence Of The Surrounding Temperature":"max. 95% to 55°C, max. 55% to 70°C, max. 35% to 75°C","Type Of Voltage Of The Operating Voltage":"AC","at DC according to IEC 60947-2 rated value":"15 kA","Value Range Of The Supply Voltage Frequency":"50/60 Hz","operating voltage at DC rated value maximum":"72 V","with multi-phase operation at AC rated value":"440 V","with single-phase operation at AC rated value":"440 V","at AC according to UL 1077 and CSA C22.2 No.235":"5 kA","vibration resistance according to IEC 60068-2-6":"±1mm at 5 to 25Hz; 50m/s² at 25 to 150Hz","Mechanical Service Life (Operating Cycles) Typical":"10 000","Product Extension Installable Supplementary Devices":"Yes","supply voltage with single-phase operation at AC rated value":"230 V","power loss [W] for rated value of the current at AC in hot operating state per pole":"0.9 W"}},"commercial":{"minOrderQty":null,"leadTime":null,"referencePrice":null,"stockQuantity":0,"priceTiers":null},"links":{"datasheetUrl":"https://cdn.aoctrl.com/ffbf60f35db810035d25f97de6c34ca6.pdf","sourceUrl":"https://support.industry.siemens.com/webbackend/api/ProductSupport/TechnicalData?language=en&region=cn&productId=387521&mlfb=5SY8208-7"},"ai":{"faq":[{"question":"How do I get current pricing and availability for 5SY8208-7?","answer":"Submit an RFQ through this listing. Pricing and stock are confirmed at quote time; the part is sourced to order through independent distribution channels."},{"question":"Will 5SY8208-7 drop into a panel specified around 5SY4304-7CV without rewiring?","answer":"Both are 2-pole C-curve MCBs in the SENTRON 5SY family with the same 36 mm width and DIN-rail mount, so they swap without re-drilling or re-looming. The key difference is breaking capacity: 5SY8208-7 carries 40 kA per IEC 60947-2, while the 5SY4304-7CV is a lower-rated variant — verify the fault current at your panel's service entrance before substituting."},{"question":"What compliance documentation does Siemens provide for 5SY8208-7?","answer":"The breaker is designed to IEC / EN 60947-2 and UL 1077. It is halogen-free and silicon-free, which supports RoHS and REACH compliance declarations. Standard Siemens documentation includes the declaration of conformity and the UL recognition file."},{"question":"What is 5SY8208-7's listed depth?","answer":"Overall depth is 76 mm; installation depth is 70 mm."},{"question":"What is 5SY8208-7's listed width?","answer":"Width is 36 mm, which is 2 modular units on a standard DIN rail."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"icboms-matrix-langgraph","citationUrl":"https://aoctrl.com/siemens/5SY8208-7","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/5SY8208-7 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}}