{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"5SY7203-8","brand":"Siemens","brandSlug":"siemens","productSlug":"5SY7203-8","canonicalUrl":"https://aoctrl.com/siemens/5SY7203-8","factsUrl":"https://aoctrl.com/api/mcp/products/5SY7203-8","rawCanonicalId":null},"summary":{"shortDescription":"Siemens SENTRON 5SY7203-8, 2-pole miniature circuit breaker, D tripping characteristic, 15 kA (IEC 60898-1) / 40 kA (IEC 60947-2), 400 V AC, 60 V DC.","salesMarkdown":"## What this MCB is and what the ratings mean The Siemens 5SY7203-8 is a 2-pole miniature circuit breaker from the SENTRON family, designed for branch-circuit protection in industrial control panels. The D tripping characteristic means it tolerates high inrush currents — typically found with motor loads, transformers, or welding equipment — without nuisance tripping on startup. The 15 kA breaking capacity per IEC 60898-1 is the rating for domestic-type installations; the 40 kA per IEC 60947-2 is the industrial rating, telling you this breaker can safely interrupt a fault current up to 40 kA at 400 V AC in an industrial distribution board. That 40 kA figure is the one that matters for panel SCCR calculations in a plant environment. ## Panel fit and mounting Width is 36 mm (2 modular units), depth 76 mm, height 90 mm. Snaps onto DIN rail via the quick-assembly system; mounting position is any, which helps when you're packing a dense gland plate. The IP20 rating applies with conductors connected — standard for inside a closed panel. Installation depth is 70 mm, so plan for that behind the DIN rail. ## Standards and compliance Rated to IEC / EN 60898-1 and IEC / EN 60947-2, plus UL 1077. That dual rating covers both residential-style and industrial applications. The breaker is halogen-free and silicon-free, which matters for clean-room or sensitive electronics environments. Pollution degree 3 and overvoltage category III suit it for fixed industrial installations.","metaTitle":"Siemens 5SY7203-8 SENTRON MCB, 2P D-curve, 15kA IEC 60898-1","metaDescription":"Siemens 5SY7203-8 SENTRON miniature circuit breaker, 2-pole, D tripping characteristic, 15 kA per IEC 60898-1, 40 kA per IEC 60947-2. Current production. Sourced 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","title":"5SY7203-8","Height":"90 mm","Maximum":"75 °C","Minimum":"-40 °C","Sealable":"Yes","Standard":"IEC / EN 60898-1, IEC / EN 60947-2 / UL1077","description":"Miniature circuit breaker 400 V 15kA, 2-pole, D, 3 A, D=70 mm","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":"D","according to EN 60898 rated value":"15 kA","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":"1.2 W"}},"commercial":{"minOrderQty":null,"leadTime":null,"referencePrice":null,"stockQuantity":0,"priceTiers":null},"links":{"datasheetUrl":"https://cdn.aoctrl.com/c6d2419f29418efe6bff85e8e0564f4c.pdf","sourceUrl":"https://support.industry.siemens.com/webbackend/api/ProductSupport/TechnicalData?language=en&region=cn&productId=168057&mlfb=5SY7203-8"},"ai":{"faq":[{"question":"What is the breaking capacity of 5SY7203-8?","answer":"15 kA per IEC 60898-1 and 40 kA per IEC 60947-2 at 400 V AC. At DC (60 V) it is 15 kA per IEC 60947-2. Under UL 1077 it is 5 kA."},{"question":"Will 5SY7203-8 drop into a panel specified for 5SY4140-7?","answer":"Both are 2-pole SENTRON MCBs on the same DIN-rail footprint, so the mechanical fit is the same. The difference is tripping characteristic: 5SY7203-8 is D-curve (for motor/transformer loads), while 5SY4140-7 is B-curve (for resistive/light loads). Verify the load type before swapping."},{"question":"Where can I buy 5SY7203-8 and how is it quoted?","answer":"Sourced and quoted to order against an RFQ through independent distribution. Availability and current pricing are confirmed at quote time."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"icboms-matrix-langgraph","citationUrl":"https://aoctrl.com/siemens/5SY7203-8","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/5SY7203-8 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}}