{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"5SY4120-5","brand":"Siemens","brandSlug":"siemens","productSlug":"5SY4120-5","canonicalUrl":"https://aoctrl.com/siemens/5SY4120-5","factsUrl":"https://aoctrl.com/api/mcp/products/5SY4120-5","rawCanonicalId":null},"summary":{"shortDescription":"Siemens SENTRON miniature circuit breaker, 5SY4120-5, 1-pole 20 A, tripping characteristic A, 10 kA breaking capacity per EN 60898, 20 kA per IEC 60947-2, 18 mm wide, IP20.","salesMarkdown":"It breaks 10 kA per EN 60898 and 20 kA per IEC 60947-2, with a DC breaking capacity of 15 kA per IEC 60947-2. Characteristic A trips between 2 and 3 times rated current — faster than B or C curves — making it the right choice for protecting semiconductor loads, control transformers, or long cable runs where inrush is minimal and you need tight overcurrent protection. At 20 A it covers a 4 kW resistive load on a 230 V single-phase line. The 15 kA DC rating per IEC 60947-2 covers DC control circuits up to that fault level — verify polarity and arc-chamber orientation for DC use. Temperature derating is built in: at 40 °C ambient the breaker carries 18.78 A, at 50 °C it drops to 17.48 A, and at 60 °C to 16.08 A. The 18 mm width (1 modular unit) fits standard DIN-rail enclosures.","metaTitle":"Siemens SENTRON 5SY4120-5 MCB, 1P 20A Char A, 10kA IEC 60898","metaDescription":"Siemens SENTRON 5SY4120-5 miniature circuit breaker, 1-pole 20 A, tripping characteristic A, 10 kA per IEC 60898 / 20 kA per IEC 60947-2. Current production. Quoted to order.","metaKeywords":null},"attributes":{"series":null,"packageCase":null,"mountingType":null,"rohsStatus":null,"productStatus":"Active","categoryPath":["1-Pole MCB (DIN Rail)"],"specifications":{"Depth":"76 mm","Width":"18 mm","title":"5SY4120-5","Height":"90 mm","Maximum":"75 °C","Minimum":"-40 °C","Sealable":"Yes","description":"Miniature circuit breaker 230/400 V 10kA, 1-pole, A, 20A, D=70 mm","Halogen-Free":"Yes","Silicon-Free":"Yes","Design Of Pole":"1P","Number Of Poles":"1","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":"20 A","protection class IP":"IP20, with connected conductors","Overvoltage Category":"III","Combined Terminal Top":"Yes","acc. to DIN EN 61346-2":"F","at 35 °C / rated value":"20 A","at 40 °C / rated value":"18.78 A","at 45 °C / rated value":"18.14 A","at 50 °C / rated value":"17.48 A","at 55 °C / rated value":"16.8 A","at 60 °C / rated value":"16.08 A","Combined Terminal Bottom":"Yes","Suitability For Operation":"Mechanical engineering / industry","Number Of Modular Width Units":"1","Tripping Characteristic Class":"A","acc. to EN 60898 / rated value":"10 kA","Position / Of Power Supply Cord":"Any","acc. to IEC 60947-2 / rated value":"20 kA","Product Feature / Touch Protection":"Yes","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","Type Of Voltage / Of The Operating Voltage":"AC","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 Component / 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 (Switching Cycles) / Typical":"10 000"}},"commercial":{"minOrderQty":null,"leadTime":null,"referencePrice":"$65.93","stockQuantity":0,"priceTiers":null},"links":{"datasheetUrl":"https://cdn.aoctrl.com/c172e85b3a0a40515ca2803202e465f5.pdf","sourceUrl":"https://support.industry.siemens.com/webbackend/api/ProductSupport/TechnicalData?language=en&region=cn&productId=94590&mlfb=5SY4120-5"},"ai":{"faq":[{"question":"What is 5SY4120-5's breaking capacity?","answer":"It breaks 10 kA per EN 60898, 20 kA per IEC 60947-2, and 15 kA DC per IEC 60947-2."},{"question":"What is the temperature derating for 5SY4120-5?","answer":"At 40 °C it carries 18.78 A, at 50 °C 17.48 A, and at 60 °C 16.08 A."},{"question":"Where can I buy 5SY4120-5?","answer":"The 5SY4120-5 is sourced and quoted to order against an RFQ through independent distribution; availability and current pricing are confirmed at quote time."},{"question":"What compliance documentation does Siemens provide for 5SY4120-5?","answer":"The breaker is halogen-free and silicon-free, rated IP20 with connected conductors, and meets overvoltage category III and pollution degree 3 per IEC standards. Specific RoHS/REACH/UL declarations are available from the manufacturer upon request."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"icboms-matrix-langgraph","citationUrl":"https://aoctrl.com/siemens/5SY4120-5","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/5SY4120-5 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}}