{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"5SL7120-3RC","brand":"Siemens","brandSlug":"siemens","productSlug":"5SL7120-3RC","canonicalUrl":"https://aoctrl.com/siemens/5SL7120-3RC","factsUrl":"https://aoctrl.com/api/mcp/products/5SL7120-3RC","rawCanonicalId":null},"summary":{"shortDescription":"Siemens Betagard miniature circuit breaker, 5SL7120-3RC, 1-pole, 20 A rated, K tripping characteristic, 15 kA breaking capacity per EN 60898 and IEC 60947-2.","salesMarkdown":"The Siemens Betagard 5SL7120-3RC is a 1-pole miniature circuit breaker rated 20 A at AC with a K tripping characteristic, breaking capacity of 15 kA per both EN 60898 and IEC 60947-2. The K characteristic means it is designed for motor and transformer circuits where inrush currents are higher than resistive loads — the magnetic trip threshold is typically 8–12x rated current, so it holds through startup surges without nuisance tripping on a 20 A line feeding a small motor or inductive load. ## Temperature derating and real-world current The 20 A rating is at 50 °C ambient. At 30 °C the breaker can carry 21.8 A continuously; at 40 °C it handles 20.9 A; at 45 °C it's 20.5 A; at 55 °C it derates to 19.5 A; at 60 °C it carries 19 A. This matters when the breaker is packed into a warm panel alongside other heat sources — the actual trip point shifts with the thermal element, so a 20 A breaker in a 60 °C cabinet is effectively a 19 A device. Plan your load margin accordingly.","metaTitle":"Siemens Betagard 5SL7120-3RC MCB, 20A 1P K-Char 15kA","metaDescription":"Siemens Betagard 5SL7120-3RC miniature circuit breaker, 20A rated, 1-pole, K characteristic, 15kA breaking capacity per EN 60898 & IEC 60947-2. Active production. Quoted to order.","metaKeywords":null},"attributes":{"series":null,"packageCase":null,"mountingType":null,"rohsStatus":null,"productStatus":null,"categoryPath":["1-Pole MCB (DIN Rail)"],"specifications":{"Depth":"76 mm","Width":"18 mm","title":"5SL7120-3RC","Height":"90 mm","Maximum":"75 °C","Minimum":"-40 °C","Sealable":"Yes","description":"Miniature Circuit Breaker 20A 1-pole K characteristic 15kA","Halogen-Free":"Yes","Silicon-Free":"Yes","Design Of Pole":"1P","Number Of Poles":"1","lifecycle_stage":"current","Mounting Position":"any","Installation Depth":"70 mm","Product Brand Name":"Betagard","Degree Of Pollution":"3","Product Designation":"Miniature circuit breaker","at AC / rated value":"20 A","protection class IP":"IP20, with connected conductors","Overvoltage Category":"III","according to EN 61346-2":"F","at 30 °C / rated value":"21.8 A","at 40 °C / rated value":"20.9 A","at 45 °C / rated value":"20.5 A","at 50 °C / rated value":"20 A","at 55 °C / rated value":"19.5 A","at 60 °C / rated value":"19 A","according to IEC 81346-2":"F","Number Of Modular Width Units":"1","Tripping Characteristic Class":"K","at DC / rated value / maximum":"72 V","Product Feature / Touch Protection":"Yes","according to EN 60898 / rated value":"15 kA","according to IEC 60947-2 / rated value":"15 kA","Type Of Voltage / Of The Operating Voltage":"AC","with multi-phase operation / at AC / maximum":"440 V","Product Component / Neutral Conductor Switching":"No","with multi-phase operation / at AC / rated value":"440 V","vibration resistance / according to IEC 60068-2-6":"50 m/s² at 25 to 150 Hz","with single-phase operation / at AC / rated value":"440 V"}},"commercial":{"minOrderQty":null,"leadTime":null,"referencePrice":null,"stockQuantity":0,"priceTiers":null},"links":{"datasheetUrl":"https://cdn.aoctrl.com/0ef6747828e98ddbebf44b2955809095.pdf","sourceUrl":"https://support.industry.siemens.com/webbackend/api/ProductSupport/TechnicalData?language=en&region=cn&productId=1502402&mlfb=5SL7120-3RC"},"ai":{"faq":[{"question":"What is the breaking capacity of 5SL7120-3RC?","answer":"The breaking capacity is 15 kA per both EN 60898 and IEC 60947-2, which means it can safely interrupt fault currents up to 15,000 amps without failing."},{"question":"What does the K characteristic mean on this breaker?","answer":"The K characteristic has a magnetic trip threshold typically 8–12 times the rated current, making it suitable for motor and transformer circuits that draw high inrush current on startup without nuisance tripping."},{"question":"How do I get pricing and availability for 5SL7120-3RC?","answer":"Submit an RFQ with your quantity and target delivery window; the part is sourced to order through independent distribution, and current pricing and availability are confirmed at quote time."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"icboms-matrix-langgraph","citationUrl":"https://aoctrl.com/siemens/5SL7120-3RC","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/5SL7120-3RC 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}}