{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"5SL6125-6MB","brand":"Siemens","brandSlug":"siemens","productSlug":"5SL6125-6MB","canonicalUrl":"https://aoctrl.com/siemens/5SL6125-6MB","factsUrl":"https://aoctrl.com/api/mcp/products/5SL6125-6MB","rawCanonicalId":null},"summary":{"shortDescription":"Siemens SENTRON 5SL6125-6MB miniature circuit breaker, 1-pole, B-curve, 25 A rated current, 6 kA breaking capacity per EN 60898, 230/400 V AC.","salesMarkdown":"## Siemens 5SL6125-6MB — SENTRON 1-pole B-curve MCB, 25 A, 6 kA The Siemens 5SL6125-6MB is a SENTRON miniature circuit breaker, 1-pole, with a B tripping characteristic, rated 25 A at 30 °C and 230/400 V AC. Its 6 kA breaking capacity per EN 60898 covers most residential and light commercial branch circuits — think lighting, socket outlets, and general-purpose loads where inrush is modest. The B-curve trips between 3 and 5 times rated current, so it's a good fit for resistive and small inductive loads, but not for motor starts or transformer inrush where a C or D curve would be needed. At 18 mm wide (1 modular unit), it snaps onto standard DIN rail and occupies one slot in a distribution board. Depth is 76 mm, installation depth 70 mm — check your enclosure depth if you're retrofitting into a shallow panel. Rated for overvoltage category III and pollution degree 2, which is standard for fixed-installation downstream of the utility meter. ## What the ratings mean for fit The 25 A rating at 30 °C is the continuous current the breaker carries without tripping in a 30 °C ambient. If your panel runs hotter, you'll need to derate — the 25 A figure at 30 °C is the baseline. The 6 kA breaking capacity per EN 60898 means it can safely interrupt a fault current up to 6 kA at 230/400 V AC. That's adequate for most residential and light commercial service entrances where the prospective short-circuit current is under 6 kA. If your installation has a higher fault level (e.g., near a large transformer), you'd need a breaker with a higher breaking capacity, like the 10 kA or 15 kA variants in the 5SL series. The B-curve (3-5× In) is the standard choice for general-purpose circuits with resistive or small inductive loads. It's not intended for motor circuits or high-inrush loads — those would need a C or D curve to avoid nuisance tripping on startup. The 1-pole design switches the line conductor only; neutral is not switched. For single-phase circuits, the rated voltage is 250 V AC; for multi-phase (e.g., 2- or 3-pole ganged) it's 440 V AC maximum. ## Mechanical and environmental Rated for 10,000 mechanical switching cycles typical. Ambient temperature range -40 °C to 75 °C, which covers most indoor and sheltered outdoor installations. IP20 with connected conductors — not suitable for wet or dusty environments without additional enclosure. Halogen-free and silicon-free, which matters for installations in sensitive environments like hospitals or data centers where off-gassing from a fault could damage equipment.","metaTitle":"Siemens 5SL6125-6MB SENTRON MCB, 1P B 25A 6kA","metaDescription":"Siemens 5SL6125-6MB SENTRON miniature circuit breaker, 1-pole, B-curve, 25 A rated, 6 kA breaking capacity per EN 60898. Active production, sourced to order. Request a 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","title":"5SL6125-6MB","Height":"90 mm","Maximum":"75 °C","Minimum":"-40 °C","Sealable":"Yes","description":"Miniature circuit breaker 230/400 V 6kA, 1-pole, B, 25A","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":"SENTRON","Degree Of Pollution":"2","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","acc. to DIN EN 61346-2":"F","Energy Limitation Class":"3","at 30 °C / rated value":"25 A","Suitability For Operation":"Residential buildings/infrastructure","Number Of Modular Width Units":"1","Tripping Characteristic Class":"B","at DC / rated value / maximum":"72 V","acc. to EN 60898 / rated value":"6 kA","Product Feature / Touch Protection":"Yes","supply voltage / at AC / rated value":"400 V","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","with single-phase operation / at AC / rated value":"250 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/e5562d13cec3f78d16b1ae750ea4f1d0.pdf","sourceUrl":"https://support.industry.siemens.com/webbackend/api/ProductSupport/TechnicalData?language=en&region=cn&productId=482077&mlfb=5SL6125-6MB"},"ai":{"faq":[{"question":"Where can I buy 5SL6125-6MB and get a price?","answer":"The 5SL6125-6MB is sourced to order through our independent distribution channel. Submit an RFQ and we'll confirm current availability and pricing at quote time — no stock or price figures are published here."},{"question":"What is the closest functional second-source for 5SL6125-6MB?","answer":"The closest functional peer within the same series is the 5SL6132-6MB, which is identical in form factor (1-pole, B-curve, 6 kA, same dimensions) but rated 32 A instead of 25 A. It drops into the same panel footprint without rewiring — just swap the breaker if the load requires the higher rating. For a direct 25 A replacement, stick with the 5SL6125-6MB."},{"question":"Will 5SL6125-6MB drop into a panel specified for 5SL6132-6MB?","answer":"Yes, the 5SL6125-6MB shares the same physical footprint (18 mm width, 76 mm depth, 90 mm height) and DIN-rail mounting as the 5SL6132-6MB. It will fit without any panel modification. The only difference is the current rating — 25 A vs 32 A — so verify the load before swapping."},{"question":"What compliance documentation does Siemens provide for 5SL6125-6MB?","answer":"The 5SL6125-6MB is designed and tested per EN 60898 (breaking capacity 6 kA) and IEC 60947-2 (overvoltage category III, pollution degree 2). It carries CE marking for the European market. Siemens typically provides a declaration of conformity and technical data sheet upon request. Specific RoHS/REACH/UL documentation should be confirmed at order time."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"icboms-matrix-langgraph","citationUrl":"https://aoctrl.com/siemens/5SL6125-6MB","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/5SL6125-6MB 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}}