{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"S203-K30","brand":"ABB","brandSlug":"abb","productSlug":"S203-K30","canonicalUrl":"https://aoctrl.com/abb/S203-K30","factsUrl":"https://aoctrl.com/api/mcp/products/S203-K30","rawCanonicalId":null},"summary":{"shortDescription":"ABB S200 series miniature circuit breaker, S203-K30, 30 A, 3-pole, Trip Curve K, 480Y/277 VAC, 6 kA interrupting rating, DIN rail mount, UL 1077 supplemental protector.","salesMarkdown":"The ABB S203-K30 is a 30 A, 3-pole miniature circuit breaker from the S200 series, with a K trip curve and a 6 kA interrupting rating at 480Y/277 VAC. It snaps onto DIN rail and is listed as a UL 1077 supplemental protector per CSA 22.2 — meaning it protects downstream equipment, not the branch circuit feeder. ## K Curve vs. C or D — The Selectivity Call The K curve sits between C (5–10x In) and D (10–20x In) for magnetic trip threshold. Compared to the S203-C8 (8 A, C curve, 10 kA), the S203-K30 has a higher inrush tolerance and a lower interrupting rating (6 kA vs. 10 kA). Against the S203-D13 (10 A, D curve, 10 kA), the K30 offers three times the continuous current but a tighter magnetic band — it won't ride through the same level of transformer inrush a D curve would. ## DIN-Rail Integration — Panel Fit and Spacing Three-pole width is 3 x 17.5 mm = 52.5 mm. The S200 series uses tunnel terminals accepting up to 25 mm² conductor — strip length 10 mm, torque 2.0 Nm. No side clearance needed for heat dissipation at 30 A, but group derating applies when multiple breakers are ganged without spacing; ABB's derating table for the S200 series at 30 A suggests 0.85 factor for six adjacent units at 40 °C ambient.","metaTitle":"ABB S203-K30 Miniature Circuit Breaker, 30A, 3P, K Curve, 6","metaDescription":"ABB S203-K30 miniature circuit breaker, 30A, 3-pole, K curve, 480Y/277VAC, 6kA interrupting. UL 1077 supplemental protector. Current lifecycle, quoted to order.","metaKeywords":null},"attributes":{"series":null,"packageCase":null,"mountingType":null,"rohsStatus":null,"productStatus":null,"categoryPath":["Miniature Circuit Breakers (MCB)"],"specifications":{"Amps":"30","Type":"Trip Curve K","Poles":"3","Mounting":"DIN Rail","Volts AC":"277","lifecycle_stage":"current","Interrupt Rating AC":"6 kA"}},"commercial":{"minOrderQty":null,"leadTime":null,"referencePrice":"$22.23","priceTiers":null},"links":{"datasheetUrl":"https://cdn.aoctrl.com/1b888e9d473400bd32917551d1de57a0.pdf","sourceUrl":null,"alternativesUrl":"https://aoctrl.com/api/mcp/products/S203-K30/alternatives.json"},"ai":{"faq":[{"question":"What is S203-K30's interrupting rating and what does it mean?","answer":"6 kA at 480Y/277 VAC. That's the maximum fault current the breaker can safely interrupt under short-circuit conditions. For a UL 1077 supplemental protector, this rating applies downstream of a branch-circuit overcurrent device — it's not a service-entrance breaker. Verify the available fault current at your panel is at or below 6 kA."},{"question":"What is the K trip curve and when should I use it?","answer":"The K curve has a magnetic trip threshold of 10–14 times the rated current (300–420 A for this 30 A unit). It's designed for loads with high inrush current — motor starters, transformers, welding equipment, or solenoid banks — where a C curve would nuisance-trip on startup but a D curve might not clear a low-level fault fast enough."},{"question":"How do I get current pricing and availability for S203-K30?","answer":"Sourced and quoted to order against an RFQ through independent distribution. Availability and current pricing are confirmed at quote time — submit an RFQ with your target quantity and delivery window for a firm commercial response."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"matrix-langgraph","citationUrl":"https://aoctrl.com/abb/S203-K30","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-K30 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}}