{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"A9N21371","brand":"Schneider Electric","brandSlug":"schneider","productSlug":"A9N21371","canonicalUrl":"https://aoctrl.com/schneider/A9N21371","factsUrl":"https://aoctrl.com/api/mcp/products/A9N21371","rawCanonicalId":null},"summary":{"shortDescription":"Schneider Electric Prodis DT40N, miniature circuit breaker, 1 A, D-curve, 1P+N, 6 kA / 10 kA breaking capacity, clip-on DIN rail mount.","salesMarkdown":"The Schneider Electric A9N21371 is a Prodis DT40N miniature circuit breaker rated 1 A with a D-curve trip characteristic, 1P+N poles, and a clip-on DIN-rail mount for distribution panels. Rated 6000 A Icn at 230 V AC per EN/IEC 60898-1 and 10 kA Icu at 230–240 V AC per IEC 60947-2, this MCB covers both residential and industrial coordination requirements — the 10 kA rating is what you use for the upstream fault-withstand calculation in a commercial panel. At 1 A rated current, this is a low-current branch or control-circuit protector — sized for a small transformer primary, a contactor coil supply, or a PLC power feed, not a general lighting circuit. Thermal-magnetic trip technology combines a bimetal for overload protection (time-delayed) with a solenoid for short-circuit protection (instantaneous above the magnetic threshold). Dual certification to EN/IEC 60898-1 (domestic MCB standard) and EN/IEC 60947-2 (industrial CB standard) means this part can be specified in either a household consumer unit or an industrial distribution board — the 10 kA Icu rating under 60947-2 is the one that governs for industrial coordination studies. Pollution degree 3 per IEC 60947-2 confirms suitability for conductive-dust environments typical in industrial enclosures, not just clean residential panels. IP20 finger-safe terminals are standard for panel-mounted breakers; the enclosure provides the higher IP rating. ## Physical integration and wiring Clip-on mount to standard 35 mm DIN rail; occupies 2 × 9 mm pitches (18 mm width) for the 1P+N form factor. Tunnel-type terminals accept 0.33–10 mm² flexible or 0.75–16 mm² rigid upstream and downstream; wire strip length 13 mm, tightening torque 2 N·m. Toggle control with ON/OFF local indication; neutral position is left per the 1P+N arrangement.","metaTitle":"Schneider Electric A9N21371 DT40N MCB, 1A D-Curve 1P+N, 6kA/","metaDescription":"Schneider Electric A9N21371 DT40N Prodis MCB, 1 A rated, D-curve, 1P+N, 6 kA (IEC 60898-1) / 10 kA (IEC 60947-2) breaking capacity. Active production. Sourced to order.","metaKeywords":null},"attributes":{"series":null,"packageCase":null,"mountingType":null,"rohsStatus":null,"productStatus":"Obsolete","categoryPath":["1-Pole MCB (DIN Rail)"],"specifications":{"Depth":"78 mm","Range":"Prodis","Width":"18 mm","Colour":"White","Height":"81 mm","Standards":"EN/IEC 60898-1 EN/IEC 60947-2","Curve code":"D","9 Mm Pitches":"2","Control type":"Toggle","Network type":"AC","Product name":"DT40","Mounting mode":"Clip-on","Quality labels":"NF","Tropicalisation":"2 conforming to IEC 60068-1","lifecycle_stage":"current","Limitation class":"3 conforming to EN/IEC 60898-1","Local signalling":"ON/OFF indication","Mounting support":"DIN rail","Neutral position":"Left","Pollution degree":"3 conforming to IEC 60947-2","Range of product":"ProDis","Breaking capacity":"6000 A Icn at 230 V AC 50 Hz conforming to EN/IEC 60898-1 10 kA Icu at 230...240 V AC 50 Hz conforming to IEC 60947-2","Device short name":"DT40N","Network frequency":"50 Hz","Poles description":"1P + N","Relative humidity":"95 % at 55 °C","Tightening torque":"2 N.m","Device application":"Distribution","Operating altitude":"2000 m","[In] rated current":"1 A","Overvoltage category":"IV","Trip unit technology":"Thermal-magnetic","Electrical durability":"20000 cycles","Mechanical durability":"20000 cycles","Wire stripping length":"13 mm","Connections - terminals":"Tunnel type terminals downstream 0.33...10 mm² flexible Tunnel type terminals downstream 0.75...16 mm² rigid Tunnel type terminals upstream 0.33...10 mm² flexible Tunnel type terminals upstream 0.75...16 mm² rigid","IP degree of protection":"IP20 conforming to IEC 60529","Magnetic tripping limit":"10...14 x In","Earth-leakage protection":"Separate block","Number of protected poles":"1","Product or component type":"Miniature circuit-breaker","Suitability for isolation":"Yes","Contact position indicator":"Yes","Locking options description":"Padlocking device","[Ui] rated insulation voltage":"400 V AC 50 Hz","[Ue] rated operational voltage":"230 V AC 50 Hz between phase and neutral","Ambient air temperature for storage":"-40...70 °C","Ambient air temperature for operation":"-25...70 °C","[Ics] rated service breaking capacity":"7.5 kA 75 % x Icn at 230 V AC 50 Hz conforming to IEC 60947-2 6000 A 100 % x Icn at 230 V AC 50 Hz conforming to EN/IEC 60898-1","[Uimp] rated impulse withstand voltage":"4 kV conforming to IEC 60947-2"}},"commercial":{"minOrderQty":null,"leadTime":null,"referencePrice":null,"priceTiers":null},"links":{"datasheetUrl":"https://cdn.aoctrl.com/338e3edccc11c2740932b1fb7cd452ab.pdf","sourceUrl":"https://www.se.com/uk/en/product/A9N21371/dt40-circuit-breaker-dt40n-1p-+-n-1a-d-curve/","alternativesUrl":"https://aoctrl.com/api/mcp/products/A9N21371/alternatives.json"},"ai":{"faq":[{"question":"What is the breaking capacity of A9N21371?","answer":"6000 A Icn at 230 V AC per EN/IEC 60898-1 and 10 kA Icu at 230–240 V AC per IEC 60947-2."},{"question":"What does the D-curve mean on this breaker?","answer":"The D-curve magnetic trip operates at 10–14 × In, designed for loads with high inrush current such as small motors or transformers."},{"question":"What standards does the A9N21371 comply with?","answer":"Certified to EN/IEC 60898-1 and EN/IEC 60947-2, with pollution degree 3 and tropicalisation class 2 per IEC 60068-1."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"matrix-langgraph","citationUrl":"https://aoctrl.com/schneider/A9N21371","citationPolicyUrl":"https://aoctrl.com/llms.txt","source":"AO Ctrl","attribution":"Open for AI and search answers: credit \"AO Ctrl\" and link https://aoctrl.com/schneider/A9N21371 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}}