{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"S203-K40","brand":"ABB","brandSlug":"abb","productSlug":"S203-K40","canonicalUrl":"https://aoctrl.com/abb/S203-K40","factsUrl":"https://aoctrl.com/api/mcp/products/S203-K40","rawCanonicalId":null},"summary":{"shortDescription":"S203-K40, 3-pole miniature circuit breaker, 40 A, Trip Curve K, 277 VAC, 10 kA interrupting capacity, DIN rail mount.","salesMarkdown":"The S203-K40 is a 3-pole miniature circuit breaker rated 40 A with a Trip Curve K characteristic, meaning it trips magnetically at 8–12x rated current — designed for loads with moderate inrush like motors, transformers, and solenoid valves where a standard Curve C might nuisance-trip on startup but Curve D would be too slow for conductor protection. Rated 277 VAC phase-to-neutral. Interrupting capacity of 10 kA at 277 VAC. Mounts on standard DIN rail.","metaTitle":"S203-K40 Miniature Circuit Breaker, 3P, 40A, Curve K, DIN Ra","metaDescription":"S203-K40 MCB, 3-pole, 40A, Trip Curve K, 277VAC, 10kA interrupting capacity. Current lifecycle. Sourced to order against RFQ.","metaKeywords":null},"attributes":{"series":null,"packageCase":null,"mountingType":null,"rohsStatus":null,"productStatus":null,"categoryPath":["Miniature Circuit Breakers (MCB)"],"specifications":{"Amps":"40","Type":"Trip Curve K","Poles":"3","Mounting":"DIN Rail","Volts AC":"277","lifecycle_stage":"current","Interrupt Rating AC":"10 kA"}},"commercial":{"minOrderQty":null,"leadTime":null,"referencePrice":"$25.40","priceTiers":null},"links":{"datasheetUrl":"https://cdn.aoctrl.com/1b888e9d473400bd32917551d1de57a0.pdf","sourceUrl":null,"alternativesUrl":"https://aoctrl.com/api/mcp/products/S203-K40/alternatives.json"},"ai":{"faq":[{"question":"Will S203-K40 drop into a panel that was specified around S203-D13 without rewiring?","answer":"Physically yes — both mount on the same DIN rail and share the same 3-pole footprint. But the K40 is 40 A vs 10 A, so the downstream conductor and load must be rated for 40 A. The trip curve is also different (K vs D), so coordination with upstream devices may change."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"matrix-langgraph","citationUrl":"https://aoctrl.com/abb/S203-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/S203-K40 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}}