{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"5SY4303-6","brand":"Siemens","brandSlug":"siemens","productSlug":"5SY4303-6","canonicalUrl":"https://aoctrl.com/siemens/5SY4303-6","factsUrl":"https://aoctrl.com/api/mcp/products/5SY4303-6","rawCanonicalId":null},"summary":{"shortDescription":"Siemens SENTRON 5SY4303-6, miniature circuit breaker, 3-pole, 3 A, B characteristic, 10 kA (IEC 60898) / 35 kA (IEC 60947-2), 2 MW, IP20.","salesMarkdown":"Rated current is 3 A at 35 °C ambient, but the datasheet provides a full derating curve: 2.88 A at 40 °C, 2.82 A at 45 °C, 2.76 A at 50 °C, 2.69 A at 55 °C, and 2.63 A at 60 °C. The B-curve's magnetic trip at 3–5× In means it will clear a hard short quickly, but it may nuisance-trip on the capacitor inrush of a small power supply if the supply is oversized relative to the 3 A rating. The combined terminal design accepts top and bottom feed, and the supply cord position is any — no orientation restrictions for the line/load side. The 76 mm depth includes the breaker body; the 90 mm height is the overall profile including the toggle and terminals.","metaTitle":"5SY4303-6 SENTRON MCB, 3A B-Char 10kA IEC 3P","metaDescription":"Siemens SENTRON 5SY4303-6 miniature circuit breaker, 3A B-curve, 3-pole, 10 kA per IEC 60898. Active production, sourced to order. Quoted on request.","metaKeywords":null},"attributes":{"series":null,"packageCase":null,"mountingType":null,"rohsStatus":null,"productStatus":"Active","categoryPath":["3-Pole MCB (DIN Rail)"],"specifications":{"Depth":"76 mm","Width":"54 mm","title":"5SY4303-6","Height":"90 mm","Maximum":"75 °C","Minimum":"-40 °C","Sealable":"Yes","Standard":"IEC / EN 60898-1, IEC / EN 60947-2 / UL1077","description":"MCB 400V AC 10kA, 3-pole, B, 3A, T=70mm","Halogen-Free":"Yes","Silicon-Free":"Yes","Design Of Pole":"3P","Number Of Poles":"3","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","at AC / rated value":"3 A","protection class IP":"IP20, with connected conductors","Overvoltage Category":"III","Combined Terminal Top":"Yes","Energy Limitation Class":"3","according to EN 61346-2":"F","at 35 °C / rated value":"3 A","at 40 °C / rated value":"2.88 A","at 45 °C / rated value":"2.82 A","at 50 °C / rated value":"2.76 A","at 55 °C / rated value":"2.69 A","at 60 °C / rated value":"2.63 A","Combined Terminal Bottom":"Yes","according to IEC 81346-2":"F","Suitability For Operation":"Mechanical engineering / industry","Number Of Modular Width Units":"2","Tripping Characteristic Class":"B","Position / Of Power Supply Cord":"Any","Product Feature / Touch Protection":"Yes","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","Product Component / Neutral Conductor Switching":"No","with multi-phase operation / at AC / rated value":"440 V","operating voltage / at DC / rated value / maximum":"72 V","vibration resistance / according to IEC 60068-2-6":"±1mm at 5 to 25Hz; 50m/s² at 25 to 150Hz","with single-phase operation / at AC / rated value":"440 V","Mechanical Service Life (Switching Cycles) / Typical":"10 000"}},"commercial":{"minOrderQty":null,"leadTime":null,"referencePrice":null,"stockQuantity":0,"priceTiers":null},"links":{"datasheetUrl":"https://cdn.aoctrl.com/3e63342457975ad947fe53cc99f2e2c5.pdf","sourceUrl":"https://support.industry.siemens.com/webbackend/api/ProductSupport/TechnicalData?language=en&region=cn&productId=1385692&mlfb=5SY4303-6"},"ai":{"faq":[{"question":"What is the breaking capacity of 5SY4303-6?","answer":"10 kA per IEC 60898 and 35 kA per IEC 60947-2. The higher IEC 60947-2 rating qualifies it for supplementary protection in industrial panels where fault currents may exceed 10 kA."},{"question":"What compliance documentation does Siemens provide for 5SY4303-6?","answer":"The breaker is certified to IEC / EN 60898-1, IEC / EN 60947-2, and UL 1077. It is halogen-free and silicon-free. Standard documentation includes the declaration of conformity, CE marking, and the manufacturer's test certificate."},{"question":"Where can I buy 5SY4303-6 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 — no stock count or price is published here."},{"question":"Will 5SY4303-6 drop into a panel specified around 5SY4301-7CV?","answer":"Both are 3-pole SENTRON MCBs in the same 2-MW DIN-rail footprint, so the mechanical fit is identical. The difference is the current rating: 5SY4301-7CV is 1 A, while 5SY4303-6 is 3 A. If the panel's branch circuit is designed for 1 A, swapping to 3 A may require a conductor and load review."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"icboms-matrix-langgraph","citationUrl":"https://aoctrl.com/siemens/5SY4303-6","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/5SY4303-6 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}}