{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"5SY4125-6","brand":"Siemens","brandSlug":"siemens","productSlug":"5SY4125-6","canonicalUrl":"https://aoctrl.com/siemens/5SY4125-6","factsUrl":"https://aoctrl.com/api/mcp/products/5SY4125-6","rawCanonicalId":null},"summary":{"shortDescription":"Siemens SENTRON 5SY4125-6, 1-pole miniature circuit breaker, B characteristic, 10 kA (EN 60898) / 20 kA (IEC 60947-2), 400 V AC, 18 mm width, IP20.","salesMarkdown":"## Integrator note — B-curve MCB for 400 V AC branch circuits It breaks 10 kA per EN 60898-1 and 20 kA per IEC 60947-2, with a DC breaking capacity of 15 kA per IEC 60947-2. Occupies a single 18 mm modular width on DIN rail, mounts in any position, and accepts supply from either end. The quick-assembly system clips onto the rail without tools. ## Sourcing & lifecycle — active, no phase-out signal Lifecycle status is current. The 5SY4125-6 remains in Siemens' active SENTRON catalog for new installations and replacement spares. ## Compliance & approvals — three-standard rated Rated under three standards: EN 60898-1 (10 kA), IEC 60947-2 (20 kA AC, 15 kA DC), and UL 1077 / CSA C22.2 No.235 (5 kA). The UL 1077 listing means it is recognized as a supplementary protector in North American panels — not a branch-circuit rated breaker per UL 489, but accepted for internal equipment protection. Halogen-free and silicon-free construction reduces outgassing in sealed enclosures. Sealable for lockout/tagout compliance. ## Panel fit — 18 mm width, 70 mm installation depth Width of 18 mm (one modular unit) and installation depth of 70 mm from the DIN rail face. Overall depth is 76 mm including the front toggle. IP20 with connected conductors means the terminals are finger-safe once wired.","metaTitle":"Siemens 5SY4125-6 SENTRON MCB, 1P B-Char, 10 kA IEC, 20 kA I","metaDescription":"Siemens 5SY4125-6 SENTRON miniature circuit breaker, 1-pole, B-curve, 10 kA (EN 60898) / 20 kA (IEC 60947-2). Active production, sourced to order. Request quote.","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","Height":"90 mm","Maximum":"75 °C","Minimum":"-40 °C","Sealable":"Yes","Standard":"IEC / EN 60898-1, IEC / EN 60947-2 / UL1077","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","at AC rated value":"400 V","at DC rated value":"60 V","Installation Depth":"70 mm","Product Brand Name":"SENTRON","Degree Of Pollution":"3","Product Designation":"Miniature circuit breaker","protection class IP":"IP20, with connected conductors","Overvoltage Category":"III","Combined Terminal Top":"Yes","Energy Limitation Class":"3","Combined Terminal Bottom":"Yes","Suitability For Operation":"Mechanical engineering / industry","Neutral Conductor Switching":"No","Number Of Modular Width Units":"1","Position Of Power Supply Cord":"Any","Tripping Characteristic Class":"B","according to EN 60898 rated value":"10 kA","according to IEC 60947-2 rated value":"20 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","Value Range Of The Supply Voltage Frequency":"50/60 Hz","operating voltage at DC rated value maximum":"72 V","with multi-phase operation at AC rated value":"440 V","with single-phase operation at AC rated value":"440 V","at AC according to UL 1077 and CSA C22.2 No.235":"5 kA","vibration resistance according to IEC 60068-2-6":"±1mm at 5 to 25Hz; 50m/s² at 25 to 150Hz","Mechanical Service Life (Operating Cycles) Typical":"10 000","Product Extension Installable Supplementary Devices":"Yes","supply voltage with single-phase operation at AC rated value":"230 V","power loss [W] for rated value of the current at AC in hot operating state per pole":"2.4 W"}},"commercial":{"minOrderQty":null,"leadTime":null,"referencePrice":"$68.84","priceTiers":null},"links":{"datasheetUrl":null,"sourceUrl":"https://support.industry.siemens.com/webbackend/api/ProductSupport/TechnicalData?language=en&region=cn&productId=534513&mlfb=5SY4125-6","alternativesUrl":"https://aoctrl.com/api/mcp/products/5SY4125-6/alternatives.json"},"ai":{"faq":[{"question":"Where can I buy 5SY4125-6 and how do I get a price?","answer":"Sourced and quoted to order against an RFQ through independent distribution. Availability and current pricing are confirmed at quote time — submit an RFQ for a firm price and lead time."},{"question":"What is the closest functional second-source to 5SY4125-6?","answer":"Within the same SENTRON family, the 5SY4140-7 is a 1-pole B-curve MCB but with a higher rated current. The 5SY4125-6 is a 25 A version; the 5SY4140-7 is a 40 A version. Both share the same 18 mm width, same breaking capacities (10 kA EN 60898, 20 kA IEC 60947-2), and same DIN-rail footprint. They are form-fit-function interchangeable at the same current rating — but the 40 A unit will not drop in as a substitute for a 25 A branch without recalculating the load."},{"question":"What compliance documentation does Siemens provide for 5SY4125-6?","answer":"The breaker is rated under EN 60898-1, IEC 60947-2, and UL 1077 / CSA C22.2 No.235. It is halogen-free and silicon-free. RoHS and REACH declarations are standard for Siemens SENTRON products; the manufacturer's declaration is available on request."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"matrix-langgraph","citationUrl":"https://aoctrl.com/siemens/5SY4125-6","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/5SY4125-6 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}}