{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"5SY4125-7KK11","brand":"Siemens","brandSlug":"siemens","productSlug":"5SY4125-7KK11","canonicalUrl":"https://aoctrl.com/siemens/5SY4125-7KK11","factsUrl":"https://aoctrl.com/api/mcp/products/5SY4125-7KK11","rawCanonicalId":null},"summary":{"shortDescription":"Siemens SENTRON miniature circuit breaker, 5SY4125-7KK11, 1-pole, 25 A rated at AC, C tripping characteristic, 10 kA breaking capacity per EN 60898, 20 kA per IEC 60947-2, IP20, -40 to 75 °C.","salesMarkdown":"It's designed for railway applications and mechanical engineering/industry panels — the -40 to 75 °C range and pollution degree 3 rating tell you it lives in a cabinet, not a climate-controlled server room. That dual rating matters: EN 60898 is the residential/commercial standard; IEC 60947-2 is the industrial standard. The 20 kA figure gives you headroom for high-fault industrial feeds — a panel fed from a 630 kVA transformer can push 18 kA prospective, and this breaker handles it without cascading upstream. Lifecycle stage is current. ## Integration and mounting details Snap-on DIN rail mount, 18 mm wide (1 MW). Combined terminal top and bottom — wire from either direction. Touch protection is built in. ## Temperature derating you need to know The 25 A rating holds at 35 °C. At 40 °C it's 23.8 A; at 50 °C it's 22.55 A; at 60 °C it's 21.2 A. If your panel ambient runs 50 °C, size the load at 22.5 A, not 25. The maximum ambient is 75 °C, but at that point the breaker is derated to about 35% of nominal — that's a survival limit, not an operating point.","metaTitle":"Siemens 5SY4125-7KK11 SENTRON MCB, 25 A, 1P, C-Curve, 10 kA","metaDescription":"Siemens 5SY4125-7KK11 SENTRON miniature circuit breaker, 25 A rated, 1-pole, C characteristic, 10 kA (EN 60898) / 20 kA (IEC 60947-2). IP20, -40 to 75°C. Sourced to order against R","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","Height":"90 mm","Maximum":"75 °C","Minimum":"-40 °C","Sealable":"Yes","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":"25 A","protection class IP":"IP20, with connected conductors","Overvoltage Category":"III","Combined Terminal Top":"Yes","Design Of The Product":"For railway applications","acc. to DIN EN 61346-2":"F","Energy Limitation Class":"3","at 35 °C / rated value":"25 A","at 40 °C / rated value":"23.8 A","at 45 °C / rated value":"23.18 A","at 50 °C / rated value":"22.55 A","at 55 °C / rated value":"21.88 A","at 60 °C / rated value":"21.2 A","Combined Terminal Bottom":"Yes","Suitability For Operation":"Mechanical engineering / industry","Number Of Modular Width Units":"1","Tripping Characteristic Class":"C","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":null,"priceTiers":null},"links":{"datasheetUrl":null,"sourceUrl":"https://support.industry.siemens.com/webbackend/api/ProductSupport/TechnicalData?language=en&region=cn&productId=4545&mlfb=5SY4125-7KK11","alternativesUrl":"https://aoctrl.com/api/mcp/products/5SY4125-7KK11/alternatives.json"},"ai":{"faq":[{"question":"Will 5SY4125-7KK11 drop into a panel specified for 5SY4125-7CV without rewiring?","answer":"Both are 1-pole SENTRON MCBs with the same 18 mm width and DIN-rail mount. The 7KK11 variant is the railway-design version with a wider temperature range (-40 to 75 °C) and halogen-free construction. Footprint and terminal layout are identical — no rewiring needed for the swap."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"matrix-langgraph","citationUrl":"https://aoctrl.com/siemens/5SY4125-7KK11","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/5SY4125-7KK11 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}}