{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"5SY8403-7","brand":"Siemens","brandSlug":"siemens","productSlug":"5SY8403-7","canonicalUrl":"https://aoctrl.com/siemens/5SY8403-7","factsUrl":"https://aoctrl.com/api/mcp/products/5SY8403-7","rawCanonicalId":null},"summary":{"shortDescription":"Siemens SENTRON miniature circuit breaker, 5SY8403-7, 4-pole, C tripping characteristic, 3 A rated current, 50 kA breaking capacity at AC per IEC 60947-2.","salesMarkdown":"## Siemens SENTRON 5SY8403-7 — 4-pole C-curve MCB, 3 A, 50 kA The Siemens SENTRON 5SY8403-7 is a 4-pole miniature circuit breaker (MCB) with a C tripping characteristic, rated at 3 A at AC and offering a 50 kA breaking capacity at AC per IEC 60947-2. It is designed for panel mounting in industrial and commercial distribution boards, protecting circuits against overloads and short circuits up to that fault level. The IP20 protection rating with connected conductors applies once wired inside an enclosure. That is a high-interrupting rating for a 3 A MCB, giving strong selectivity headroom in a distribution panel where fault currents can be substantial. The DC breaking capacity is 15 kA per the same standard, so it also handles DC circuits in the same panel. The 3 A rating is temperature-sensitive: at 45 °C it holds at 3 A, but at 50 °C it derates to 2.92 A, and at 55 °C to 2.85 A. The ambient temperature range itself is wide: -40 to 75 °C, so it is fine in unheated enclosures or near hot equipment as long as the load current is adjusted. Vibration resistance per IEC 60068-2-6 is ±1 mm at 5 to 25 Hz and 50 m/s² at 25 to 150 Hz, which covers typical industrial panel vibration from nearby motors and conveyors. The halogen-free and silicon-free construction is relevant for environments sensitive to outgassing — clean rooms, semiconductor fabs, or food processing areas where silicone contamination is a concern.","metaTitle":"Siemens SENTRON 5SY8403-7 MCB, 4P, C-Curve, 3 A, 50 kA","metaDescription":"Siemens SENTRON 5SY8403-7 miniature circuit breaker, 4-pole, C-curve, 3 A rated, 50 kA breaking capacity at AC per IEC 60947-2. Active production, sourced to order.","metaKeywords":null},"attributes":{"series":null,"packageCase":null,"mountingType":null,"rohsStatus":null,"productStatus":"Active","categoryPath":["Miniature Circuit Breakers (MCB)"],"specifications":{"Depth":"76 mm","Width":"72 mm","Height":"90 mm","Maximum":"75 °C","Minimum":"-40 °C","Sealable":"Yes","Halogen-Free":"Yes","Silicon-Free":"Yes","Number Of Poles":"4","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":"3 A","protection class IP":"IP20, with connected conductors","Overvoltage Category":"III","Combined Terminal Top":"Yes","Number Of Poles / Note":"4P","acc. to DIN EN 61346-2":"F","at 45 °C / rated value":"3 A","at 50 °C / rated value":"2.92 A","at 55 °C / rated value":"2.85 A","Combined Terminal Bottom":"Yes","Suitability For Operation":"Mechanical engineering / industry","Number Of Modular Width Units":"4","Tripping Characteristic Class":"C","Position / Of Power Supply Cord":"Any","acc. to IEC 60947-2 / rated value":"50 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,"priceTiers":null},"links":{"datasheetUrl":null,"sourceUrl":"https://support.industry.siemens.com/webbackend/api/ProductSupport/TechnicalData?language=en&region=cn&productId=162439&mlfb=5SY8403-7","alternativesUrl":"https://aoctrl.com/api/mcp/products/5SY8403-7/alternatives.json"},"ai":{"faq":[{"question":"Where can I buy 5SY8403-7 and how do I get a price?","answer":"This part is sourced and quoted to order against an RFQ through independent distribution. Submit an RFQ for current pricing and availability — it is confirmed at quote time."},{"question":"What is the breaking capacity of 5SY8403-7?","answer":"The breaking capacity is 50 kA at AC per IEC 60947-2, and 15 kA at DC per the same standard. For UL 1077/CSA C22.2 No.235, the rating is 5 kA at AC."},{"question":"What is the ambient temperature range for 5SY8403-7?","answer":"It operates from -40 °C to 75 °C, but the 3 A rating derates above 45 °C: 2.92 A at 50 °C, 2.85 A at 55 °C."},{"question":"Will 5SY8403-7 drop into a panel specified around 5SY6332-7CC?","answer":"Both are 4-pole SENTRON MCBs with similar mounting — 72 mm width (4 MUs), DIN rail snap-on. The 5SY8403-7 is a 3 A C-curve; the 5SY6332-7CC is a different rating. Check your current and curve requirements before swapping, but the footprint and busbar compatibility are the same."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"matrix-langgraph","citationUrl":"https://aoctrl.com/siemens/5SY8403-7","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/5SY8403-7 when reusing this data. Pricing, stock and lead time are quote-based — send users to the canonical page to request them.","lastUpdated":"2026-09-02T08:15:54.622Z","lastPublished":"2026-09-02T08:15:54.622Z","indexable":true}}