{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"A9N21388","brand":"Schneider Electric","brandSlug":"schneider","productSlug":"A9N21388","canonicalUrl":"https://aoctrl.com/schneider/A9N21388","factsUrl":"https://aoctrl.com/api/mcp/products/A9N21388","rawCanonicalId":null},"summary":{"shortDescription":"Schneider Electric ProDis series, DT40N miniature circuit-breaker, A9N21388, 3P, 25 A, C-curve, 6 kA Icn / 10 kA Icu, DIN rail clip-on.","salesMarkdown":"The Schneider Electric A9N21388 is a DT40N miniature circuit-breaker from the ProDis range, rated 25 A with a C-curve trip characteristic (magnetic tripping between 5 and 10 times In). Breaking capacity is 6 kA Icn at 400 V AC per EN/IEC 60898-1, and 10 kA Icu at 400–415 V AC per IEC 60947-2 — the dual rating means it satisfies both the household-standard and the industrial-standard for the same installation, giving the specifying engineer headroom for fault-level coordination. At 25 A and C-curve, this breaker is sized for general-purpose lighting and socket-outlet circuits where inrush from fluorescent ballasts or small motor loads is moderate — the C-curve holds through short-duration surges up to 10x rated current before the magnetic trip operates. The thermal-magnetic trip unit combines a bimetal element for overload protection (time-delayed) with a solenoid for short-circuit protection (instantaneous above the magnetic threshold). This covers most panel-building wiring sizes up to a 25 A circuit. ## Integration notes The toggle handle provides local ON/OFF indication. At 6 pitches of 9 mm (54 mm wide), it occupies three modular spaces in a distribution board. Depth is 78 mm, height 81 mm. IP20 finger-safe terminals per IEC 60529; suitable for enclosed panel use only. Earth-leakage protection requires a separate block — not integrated.","metaTitle":"Schneider Electric A9N21388 DT40N MCB, 25 A, 3P, C-Curve, 6","metaDescription":"Schneider Electric A9N21388 DT40N miniature circuit-breaker, 25 A rated, 3-pole, C-curve, 6 kA Icn / 10 kA Icu breaking capacity. DIN rail clip-on. Active production. Quoted to ord","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":"C","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","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","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":"5...10 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":"440 V AC 50 Hz","[Ue] rated operational voltage":"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/a8541b6b1e2fd80e0dd0a7b01497f03c.pdf","sourceUrl":"https://www.se.com/uk/en/product/A9N21388/dt40-circuit-breaker-dt40n-3p-25a-c-curve/","alternativesUrl":"https://aoctrl.com/api/mcp/products/A9N21388/alternatives.json"},"ai":{"faq":[{"question":"What is the breaking capacity of A9N21388?","answer":"The breaking capacity is 6 kA Icn at 400 V AC per EN/IEC 60898-1, and 10 kA Icu at 400–415 V AC per IEC 60947-2."},{"question":"Where can I buy A9N21388 and how is it quoted?","answer":"This part is sourced and quoted to order against an RFQ through independent distribution. Availability and current pricing are confirmed at quote time — no stock figures or price are listed here."},{"question":"What standards does A9N21388 comply with?","answer":"It complies with EN/IEC 60898-1 and EN/IEC 60947-2, giving it dual certification for both household and industrial applications."},{"question":"What is the closest alternative to A9N21388 in the same family?","answer":"Within the ProDis DT40N range, the closest alternative would be a different current rating or pole configuration — for example, a 32 A or 1P variant. No pin-compatible direct substitute exists outside the series; the A9N21388 is the specific 25 A 3P C-curve variant."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"matrix-langgraph","citationUrl":"https://aoctrl.com/schneider/A9N21388","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/A9N21388 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}}