{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"5SJ4125-6HG40","brand":"Siemens","brandSlug":"siemens","productSlug":"5SJ4125-6HG40","canonicalUrl":"https://aoctrl.com/siemens/5SJ4125-6HG40","factsUrl":"https://aoctrl.com/api/mcp/products/5SJ4125-6HG40","rawCanonicalId":null},"summary":{"shortDescription":"Siemens SENTRON 5SJ4125-6HG40, miniature circuit breaker, 1-pole, rated 25 A at 40 °C, 70 mm depth, 18 mm width, IP20/IP40.","salesMarkdown":"The 25 A rating holds flat from 30 °C through 40 °C — no derate needed in a standard 40 °C panel. At 60 °C it still carries 22 A, which is better than many compact MCBs that drop harder above 50 °C. The single-pole design switches the line only; neutral is through-bar, so this is for a single-phase branch or a 1-pole lighting/control circuit, not a multi-pole motor feed.","metaTitle":"Siemens 5SJ4125-6HG40 SENTRON MCB, 1P, 25 A, 70 mm depth","metaDescription":"Siemens 5SJ4125-6HG40 SENTRON miniature circuit breaker, 1-pole, 25 A at 40 °C, 70 mm depth, 18 mm width. Active production. Available 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":"70 mm","Width":"18 mm","title":"5SJ4125-6HG40","Height":"90 mm","Maximum":"75 °C","Minimum":"-40 °C","Sealable":"Yes","description":"Miniature circuit breaker 240 V 14kA, 1-pole, B, 25A, D=70 mm according to UL 489, equal polarity","Halogen-Free":"Yes","Silicon-Free":"Yes","Design Of Pole":"1P","Number Of Poles":"1","lifecycle_stage":"current","Fastening Method":"on standard mounting rail","Mounting Position":"any","at AC rated value":"25 A","Installation Depth":"70 mm","Product Brand Name":"SENTRON","Degree Of Pollution":"3","Product Designation":"Miniature circuit breakers","protection class IP":"IP20, with connected conductors, IP 40 in the handle range","Overvoltage Category":"3","Tunnel Terminals Top":"No","Vibration Resistance":"50 m/s² at 25 to 150Hz and 60m/s² at 35Hz (4sec)","Combined Terminal Top":"Yes","Design Of The Product":"Miniature circuit-breaker 5SJ4","Product Function Note":"Terminal tightening torque for Cu, 60/75°C; 3.5Nm/31lb.in","at 30 °C rated value":"25 A","at 40 °C rated value":"25 A","at 45 °C rated value":"24.25 A","at 50 °C rated value":"23.5 A","at 55 °C rated value":"22.7 A","at 60 °C rated value":"22 A","Tunnel Terminals Bottom":"No","according to EN 61346-2":"F","Combined Terminal Bottom":"Yes","according to IEC 81346-2":"F","Suitability For Operation":"Mechanical engineering / industry","at DC rated value maximum":"60 V","Neutral Conductor Switching":"No","Number Of Modular Width Units":"1","Position Of Power Supply Cord":"Any","Tripping Characteristic Class":"B","supply voltage at AC rated value":"400 V","according to EN 60898 rated value":"10 kA","Ambient Temperature During Operation":"max. 95% humidity","Supply Voltage Frequency Rated Value":"50 Hz","according to IEC 60947-2 rated value":"15 kA","installation environment regarding EMC":"Suitable for environment B (immunity to interference not applicable)","Type Of Voltage Of The Operating Voltage":"AC/DC","insulation voltage (Ui) at AC rated value":"440 V","Value Range Of The Supply Voltage Frequency":"50/60 Hz","vibration resistance according to IEC 60068-2-6":"±1 mm at 5 to 25 Hz; 50 m/s² at 25 to 150 Hz","Mechanical Service Life (Switching Cycles) Typical":"10 000","Product Extension Installable Supplementary Devices":"Yes","Tightening Torque With Screw-Type Terminals Maximum":"3.5 N·m","power loss [W] for rated value of the current at AC in hot operating state per pole":"3.1 W"}},"commercial":{"minOrderQty":null,"leadTime":null,"referencePrice":"$76.52","stockQuantity":0,"priceTiers":null},"links":{"datasheetUrl":"https://cdn.aoctrl.com/b36df64a065079ff9a52430e7fc40cab.pdf","sourceUrl":"https://support.industry.siemens.com/webbackend/api/ProductSupport/TechnicalData?language=en&region=cn&productId=220797&mlfb=5SJ4125-6HG40"},"ai":{"faq":[{"question":"Where can I buy 5SJ4125-6HG40 and how do I get a price?","answer":"This part is sourced and quoted to order against an RFQ through independent distribution. Availability and current pricing are confirmed at quote time — submit an RFQ through this listing."},{"question":"What is 5SJ4125-6HG40's depth and width?","answer":"Depth is 70 mm, width is 18 mm — one standard modular unit. Height is 90 mm."},{"question":"Will 5SJ4125-6HG40 drop into a panel specified around 5SL4363-7 without rewiring?","answer":"Both are 1-pole Siemens MCBs on the same 18 mm DIN-rail footprint, so mechanical fit is the same. However, the 5SJ4 series uses combined terminals (screw-clamp) while the 5SL6 uses tunnel terminals — verify the lug type on the existing wiring before ordering. The 5SJ4125-6HG40 has combined top and bottom terminals; tunnel terminals are not available."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"icboms-matrix-langgraph","citationUrl":"https://aoctrl.com/siemens/5SJ4125-6HG40","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/5SJ4125-6HG40 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}}