{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"5SY4203-5","brand":"Siemens","brandSlug":"siemens","productSlug":"5SY4203-5","canonicalUrl":"https://aoctrl.com/siemens/5SY4203-5","factsUrl":"https://aoctrl.com/api/mcp/products/5SY4203-5","rawCanonicalId":null},"summary":{"shortDescription":"Siemens SENTRON 5SY4203-5, 2-pole miniature circuit breaker, A-curve characteristic, 10 kA breaking capacity per EN 60898, 35 kA per IEC 60947-2, 2 modular width units (36 mm).","salesMarkdown":"## Breaking capacity across three standards The 5SY4203-5: For DC circuits the interrupting rating drops to 15 kA per IEC 60947-2 at 60 V DC (72 V DC max operating voltage). ## A-curve trip and what it means on the line The A-curve characteristic (tripping class A) means the magnetic trip threshold is set at 2 to 3 times rated current — lower than the more common B-curve (3–5×) or C-curve (5–10×). This makes the 5SY4203-5 the right choice for protecting semiconductor loads, control transformers, or sensitive electronic circuits where the inrush is minimal and you need fast clearing on a short-circuit. On a panel feeding PLC power supplies or instrumentation loops, the A-curve avoids nuisance trips that a C-curve would cause on the same fault current. At 36 mm wide (2 modular width units), 90 mm tall, and 76 mm deep (70 mm installation depth), this breaker occupies two standard 18 mm DIN-rail slots. The quick-assembly fastening system snaps onto the rail without tools. Mounting position is any orientation — no derating needed for horizontal or inverted placement.","metaTitle":"Siemens 5SY4203-5 SENTRON 2-Pole MCB, A-Curve, 10 kA","metaDescription":"Siemens 5SY4203-5 SENTRON 2-pole miniature circuit breaker, A-curve, rated 10 kA (EN 60898) / 35 kA (IEC 60947-2). UL1077 listed.","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":"5SY4203-5","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 10kA, 2-pole, A, 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":"A","according to EN 60898 rated value":"10 kA","according to IEC 60947-2 rated value":"35 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":"1.9 W"}},"commercial":{"minOrderQty":null,"leadTime":null,"referencePrice":"$45.72","stockQuantity":0,"priceTiers":null},"links":{"datasheetUrl":"https://cdn.aoctrl.com/a2981690943dd80996f555c1d5bd83af.pdf","sourceUrl":"https://support.industry.siemens.com/webbackend/api/ProductSupport/TechnicalData?language=en&region=cn&productId=344555&mlfb=5SY4203-5"},"ai":{"faq":[{"question":"Where can I buy Siemens 5SY4203-5 and how do I get a price?","answer":"No stock-holding claim; each order is confirmed against the supply channel at the time of quotation."},{"question":"What is the breaking capacity of Siemens 5SY4203-5?","answer":"For DC circuits the interrupting rating is 15 kA per IEC 60947-2 at 60 V DC (72 V DC max operating voltage)."},{"question":"Is 5SY4203-5 UL1077 certified?","answer":"This qualifies it as a supplementary protector for use in UL 508A industrial control panels, though it is not a branch-circuit rated device per UL 489."},{"question":"Can 5SY4203-5 be used for DC applications?","answer":"Yes. The 5SY4203-5 is rated for DC operation at 60 V nominal (72 V max operating voltage) with a 15 kA interrupting capacity per IEC 60947-2. The 2-pole design allows series connection of the poles for higher DC voltage applications — confirm the wiring configuration with the manufacturer's application notes."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"icboms-matrix-langgraph","citationUrl":"https://aoctrl.com/siemens/5SY4203-5","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/5SY4203-5 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}}