{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"A9N21418","brand":"Schneider Electric","brandSlug":"schneider","productSlug":"A9N21418","canonicalUrl":"https://aoctrl.com/schneider/A9N21418","factsUrl":"https://aoctrl.com/api/mcp/products/A9N21418","rawCanonicalId":null},"summary":{"shortDescription":"Schneider Electric Prodis DT40N miniature circuit breaker, A9N21418, 25 A rated, D curve, 3P+N, 6 kA / 10 kA breaking capacity, clip-on DIN rail mount.","salesMarkdown":"Breaking capacity is dual-rated: 6000 A Icn at 400 V AC per EN/IEC 60898-1 (the household-and-similar standard), and 10 kA Icu at 400...415 V AC per IEC 60947-2 (the industrial standard). That second figure matters when this breaker sits in an industrial panel where the prospective fault current can hit higher than a residential service entrance. ## D curve and load type — why the trip characteristic matters The D curve's magnetic trip band (10–14 x In) is the key spec for fit. A 25 A D-curve breaker will hold through the magnetizing inrush of a small motor or the charging current of a capacitor bank, where a C-curve (5–10 x In) might trip on the first half-cycle. But that same D curve also means the breaker will not clear a modest overload as quickly as a B or C — the thermal element handles the long-time overload, and the magnetic element only acts on high faults. So if your load is resistive (heaters, lighting), a D curve is overkill and you lose coordination; for motor or inductive loads, it's the right call. The breaker occupies 6 x 9 mm pitches (54 mm wide total for the 3P+N), so plan for that footprint on the rail. ## What the dual standard means for procurement The A9N21418 is certified to both EN/IEC 60898-1 (the standard for household and similar installations) and EN/IEC 60947-2 (the industrial standard for low-voltage switchgear). That dual certification is rare in a single MCB — it means this breaker can serve in a residential distribution board (60898-1) and also in an industrial control panel (60947-2) where the inspector expects the industrial standard.","metaTitle":"Schneider Electric A9N21418 DT40N MCB, 25 A D Curve, 3P+N","metaDescription":"Schneider Electric A9N21418 Prodis DT40N miniature circuit breaker, 25 A rated, D curve, 3P+N, 6 kA (IEC 60898-1) / 10 kA (IEC 60947-2) breaking capacity, clip-on DIN rail mount. A","metaKeywords":null},"attributes":{"series":null,"packageCase":null,"mountingType":null,"rohsStatus":null,"productStatus":"Obsolete","categoryPath":["Miniature Circuit Breakers (MCB)"],"specifications":{"Depth":"78 mm","Range":"Prodis","Width":"54 mm","Colour":"White","Height":"81 mm","Standards":"EN/IEC 60898-1 EN/IEC 60947-2","Curve code":"D","9 Mm Pitches":"6","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 400 V AC 50 Hz conforming to EN/IEC 60898-1 10 kA Icu at 400...415 V AC 50 Hz conforming to IEC 60947-2","Device short name":"DT40N","Network frequency":"50 Hz","Poles description":"3P + N","Relative humidity":"95 % at 55 °C","Tightening torque":"2 N.m","Device application":"Distribution","Operating altitude":"2000 m","[In] rated current":"25 A","Trip unit technology":"Thermal-magnetic","Electrical durability":"10000 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":"3","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 400 V AC 50 Hz between phases","Ambient air temperature for storage":"-40...70 °C","Ambient air temperature for operation":"-25...70 °C","[Ics] rated service breaking capacity":"6000 A 100 % x Icn at 400 V AC 50 Hz conforming to EN/IEC 60898-1 7.5 kA 75 % x Icu at 400 V AC 50 Hz conforming to IEC 60947-2","[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/9b295a88acac7345fdb131829fbb72c1.pdf","sourceUrl":"https://www.se.com/uk/en/product/A9N21418/dt40-circuit-breaker-dt40n-3p-+-n-25a-d-curve/","alternativesUrl":"https://aoctrl.com/api/mcp/products/A9N21418/alternatives.json"},"ai":{"faq":[{"question":"Where can I buy A9N21418 and how do I get a price?","answer":"The A9N21418 is sourced and quoted to order against an RFQ through independent distribution. Availability and current pricing are confirmed at quote time — submit an RFQ to get a firm price and lead time for your quantity."},{"question":"What is A9N21418's breaking capacity?","answer":"The A9N21418 has a dual breaking capacity: 6000 A Icn at 400 V AC per EN/IEC 60898-1, and 10 kA Icu at 400...415 V AC per IEC 60947-2. The 10 kA industrial rating is the one to use for panel fault calculations."},{"question":"What compliance documentation does A9N21418 carry?","answer":"The A9N21418 is certified to EN/IEC 60898-1 and EN/IEC 60947-2, carries the NF quality label, and is tropicalised per IEC 60068-1 (class 2). Pollution degree is 3 per IEC 60947-2."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"matrix-langgraph","citationUrl":"https://aoctrl.com/schneider/A9N21418","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/A9N21418 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}}