{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"5SJ4240-7HG42","brand":"Siemens","brandSlug":"siemens","productSlug":"5SJ4240-7HG42","canonicalUrl":"https://aoctrl.com/siemens/5SJ4240-7HG42","factsUrl":"https://aoctrl.com/api/mcp/products/5SJ4240-7HG42","rawCanonicalId":null},"summary":{"shortDescription":"Siemens SENTRON 5SJ4 series, 2-pole miniature circuit breaker, 40 A rated, DIN-rail mount.","salesMarkdown":"## 40 A, 2-Pole — the rating that decides the branch circuit The Siemens 5SJ4240-7HG42 is a 2-pole miniature circuit breaker from the SENTRON 5SJ4 series, rated 40 A at 30 °C and 40 °C — the same 40 A holds at both temperatures, so no derating is needed for a panel running at typical ambient. Above 40 °C the continuous current steps down: 38.8 A at 45 °C, 38 A at 50 °C, 37 A at 55 °C, and 36 A at 60 °C. That derating curve is the one to check if the breaker sits near a heat source or in a sealed enclosure. Width is 36 mm (2 modular units), height 121 mm, depth 70 mm.","metaTitle":"Siemens 5SJ4240-7HG42 2-Pole MCB 40A, SENTRON","metaDescription":"Siemens 5SJ4240-7HG42 SENTRON 2-pole MCB, 40 A rated, DIN-rail mount. Current lifecycle stage. Quoted to order against RFQ.","metaKeywords":null},"attributes":{"series":null,"packageCase":null,"mountingType":null,"rohsStatus":null,"productStatus":"Active","categoryPath":["2-Pole MCB (DIN Rail)"],"specifications":{"Depth":"70 mm","Width":"36 mm","title":"5SJ4240-7HG42","Height":"121 mm","Maximum":"75 °C","Minimum":"-40 °C","Sealable":"Yes","description":"Circuit breaker 10kA, 2-pole, C, 40 A according to UL 489-480Y/277V","Halogen-Free":"Yes","Silicon-Free":"Yes","Design Of Pole":"2P","Number Of Poles":"2","lifecycle_stage":"current","Fastening Method":"on standard mounting rail","Mounting Position":"any","at AC rated value":"40 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":"40 A","at 40 °C rated value":"40 A","at 45 °C rated value":"38.8 A","at 50 °C rated value":"38 A","at 55 °C rated value":"37 A","at 60 °C rated value":"36 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":"2","Position Of Power Supply Cord":"Any","Tripping Characteristic Class":"C","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":"4.8 W"}},"commercial":{"minOrderQty":null,"leadTime":null,"referencePrice":"$114.30 – $231.63","stockQuantity":0,"priceTiers":null},"links":{"datasheetUrl":"https://cdn.aoctrl.com/43d827d4fa3e27225738e7443c7bfa1b.pdf","sourceUrl":"https://support.industry.siemens.com/webbackend/api/ProductSupport/TechnicalData?language=en&region=cn&productId=517100&mlfb=5SJ4240-7HG42"},"ai":{"faq":[{"question":"Where can I buy Siemens 5SJ4240-7HG42?","answer":"The 5SJ4240-7HG42 is sourced to order against an RFQ through independent distribution."},{"question":"Does Siemens 5SJ4240-7HG42 have a direct replacement or equivalent?","answer":"No official successor or cross-reference has been issued. The 5SJ4240-7HG42 is the current active order code for the 40 A 2-pole position in the SENTRON 5SJ4 series."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"icboms-matrix-langgraph","citationUrl":"https://aoctrl.com/siemens/5SJ4240-7HG42","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/5SJ4240-7HG42 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}}