{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"5SJ4125-7HG42","brand":"Siemens","brandSlug":"siemens","productSlug":"5SJ4125-7HG42","canonicalUrl":"https://aoctrl.com/siemens/5SJ4125-7HG42","factsUrl":"https://aoctrl.com/api/mcp/products/5SJ4125-7HG42","rawCanonicalId":null},"summary":{"shortDescription":"Siemens SENTRON 5SJ4 miniature circuit breaker, 5SJ4125-7HG42, 1-pole C-curve 25 A, 18 mm width, 70 mm depth.","salesMarkdown":"The Siemens SENTRON 5SJ4125-7HG42 is a 1-pole miniature circuit breaker with C-curve tripping characteristic, rated 25 A at 30 °C and 40 °C. ## Ratings and fit Full rated current holds at 30 °C and 40 °C (25 A), then derates linearly to 22 A at 60 °C — useful if the breaker sits in a warm cabinet near drives or transformers. The 70 mm installation depth matches standard SENTRON 5SJ4 enclosures and most DIN-rail distribution boards; no extra clearance needed at the back. Overvoltage category 3 and pollution degree 3 mean it's rated for fixed installations in industrial environments, not just clean residential panels. IP20 with connected conductors, IP40 in the handle area — fine for enclosed panels; not for washdown zones without a separate enclosure. Vibration resistance to 50 m/s² at 25–150 Hz and 60 m/s² at 35 Hz means it holds up on machine-mounted subpanels near rotating equipment.","metaTitle":"Siemens SENTRON 5SJ4125-7HG42 MCB, 1-pole C-curve 25 A","metaDescription":"Siemens SENTRON 5SJ4125-7HG42 miniature circuit breaker, 1-pole, C-curve, 25 A rated at 30 °C. Active lifecycle, sourced to order. 18 mm width, IP20/IP40.","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":"5SJ4125-7HG42","Height":"121 mm","Maximum":"75 °C","Minimum":"-40 °C","Sealable":"Yes","description":"Circuit breaker 10kA, 1-pole, C, 25A according to UL 489-277V","Halogen-Free":"Yes","Silicon-Free":"Yes","Number Of Poles":"1","lifecycle_stage":"current","Fastening Method":"on standard mounting rail","Mounting Position":"any","Installation Depth":"70 mm","Product Brand Name":"SENTRON","Degree Of Pollution":"3","Product Designation":"Miniature circuit breakers","at AC / rated value":"25 A","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","Tunnel Terminals Bottom":"No","according to EN 61346-2":"F","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","Combined Terminal Bottom":"Yes","according to IEC 81346-2":"F","Suitability For Operation":"Mechanical engineering / industry","Neutral Conductor Switching":"No","Number Of Modular Width Units":"1","Tripping Characteristic Class":"C","at DC / rated value / maximum":"60 V","Position / Of Power Supply Cord":"Any","according to EN 60898 / rated value":"10 kA","supply voltage / at AC / rated value":"400 V","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","Mechanical Service Life (Switching Cycles) / Typical":"10 000"}},"commercial":{"minOrderQty":null,"leadTime":null,"referencePrice":"$30.48","stockQuantity":0,"priceTiers":null},"links":{"datasheetUrl":"https://cdn.aoctrl.com/c5f6a1ca8f534ce64d47e978254d9ffd.pdf","sourceUrl":"https://support.industry.siemens.com/webbackend/api/ProductSupport/TechnicalData?language=en&region=cn&productId=527443&mlfb=5SJ4125-7HG42"},"ai":{"faq":[],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"icboms-matrix-langgraph","citationUrl":"https://aoctrl.com/siemens/5SJ4125-7HG42","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/5SJ4125-7HG42 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}}