{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"S803U-K40","brand":"ABB","brandSlug":"abb","productSlug":"S803U-K40","canonicalUrl":"https://aoctrl.com/abb/S803U-K40","factsUrl":"https://aoctrl.com/api/mcp/products/S803U-K40","rawCanonicalId":null},"summary":{"shortDescription":"ABB S800 series high-performance miniature circuit breaker, S803U-K40, 40 A, 3-pole, trip curve K, 240 VAC, 50 kA interrupting capacity, cage terminal, DIN rail mount.","salesMarkdown":"The ABB S803U-K40 is a 3-pole, 40 A miniature circuit breaker from the S800 High Performance series, with a trip curve K and a 50 kA ultimate short-circuit breaking capacity at 240 VAC. It carries approvals to IEC/EN 60947-2, UL 489, and CSA 22.2 No. 5-02, making it accepted across North American and IEC panels. Trip curve K is the key spec for this part. It combines a magnetic trip threshold of 10–14× In (400–560 A instantaneously) with a thermal element that handles inrush without nuisance tripping. The 40 A rating covers a 15–20 kW motor on 400 V three-phase or a 50 A transformer primary. DIN-rail mounting means it clips directly onto a standard 35 mm rail in the panel — no bracket, no drilling. Three poles let it switch a three-phase load with a single handle; the handle ties all three poles mechanically for common trip on a phase-to-phase fault.","metaTitle":"S803U-K40 MCB, 40A 3P Curve K, 50kA SCCR, DIN Rail","metaDescription":"S803U-K40 high-performance MCB, 40 A, 3-pole, trip curve K, 50 kA interrupting capacity at 240 VAC. IEC/EN 60947-2, UL 489, CSA 22.2. Current-production, sourced to order.","metaKeywords":null},"attributes":{"series":null,"packageCase":null,"mountingType":null,"rohsStatus":null,"productStatus":null,"categoryPath":["3-Pole MCB (DIN Rail)"],"specifications":{"Amps":"40","Type":"Trip Curve K","Poles":"3","title":"S803U-K40","Mounting":"DIN Rail","Volts AC":"240","description":"MCB S800 3P K 40A|High Performance Miniature Circuit Breaker with Cage Terminal, Rated Current 40 Amps, 3 Pole, Trip Curve K, Voltage up to 240 VAC, Ultimate Short-Circuit Breaking Capacity 50 kA, IEC/EN 60947-2, UL 489, CSA 22.2 No. 5-02","lifecycle_stage":"current","Interrupt Rating AC":"50 kA"}},"commercial":{"minOrderQty":null,"leadTime":null,"referencePrice":null,"stockQuantity":0,"priceTiers":null},"links":{"datasheetUrl":"https://cdn.aoctrl.com/9177d91a64149e2679cd76505bca04b0.pdf","sourceUrl":null},"ai":{"faq":[{"question":"What compliance documentation does the S803U-K40 carry?","answer":"It is certified to IEC/EN 60947-2, UL 489, and CSA 22.2 No. 5-02. These cover the key North American and IEC standards for miniature circuit breakers."},{"question":"Where can I buy the S803U-K40?","answer":"Sourced and quoted to order against an RFQ through independent distribution. Pricing and stock confirmed at quote time — submit an RFQ for current availability."},{"question":"What is the S803U-K40's trip curve and what loads is it for?","answer":"Trip curve K, with a magnetic trip threshold of 10–14× In. It is designed for motor circuits, transformers, and inductive loads where inrush current would nuisance-trip a B or C curve."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"icboms-matrix-langgraph","citationUrl":"https://aoctrl.com/abb/S803U-K40","citationPolicyUrl":"https://aoctrl.com/llms.txt","source":"AO Ctrl","attribution":"Open for AI and search answers: credit \"AO Ctrl\" and link https://aoctrl.com/abb/S803U-K40 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}}