{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"S203-K8","brand":"ABB","brandSlug":"abb","productSlug":"S203-K8","canonicalUrl":"https://aoctrl.com/abb/S203-K8","factsUrl":"https://aoctrl.com/api/mcp/products/S203-K8","rawCanonicalId":null},"summary":{"shortDescription":"ABB S200 series, S203-K8, 3-pole miniature circuit breaker, 8 A, K-curve, 480Y/277 V AC, 6 kAIC interrupting rating, DIN rail mount, UL 1077 supplemental protector.","salesMarkdown":"## Supplemental protector for 480Y/277 V branch circuits It operates at 480Y/277 V AC and carries a 6 kA interrupting rating, listed as a UL 1077 supplemental protector. That UL 1077 classification means it protects downstream equipment in a branch circuit but is not a service-entrance or feeder breaker — it goes after the main overcurrent device, typically in a control panel or sub-distribution board. ## K-curve means motor and transformer loads The K-curve is the key selection parameter here. It allows higher inrush without nuisance tripping — typically 8–12× rated current for short magnetic trips — which suits inductive loads like small motors, transformers, and solenoid banks. A B-curve (3–5×) would trip on the same inrush; a C-curve (5–10×) sits in between. For a 8 A breaker on a 480 V control transformer or a fractional-horsepower motor, the K-curve is the right call. ## DIN-rail integration for panel builds Snap-on DIN rail mounting (standard 35 mm) means it clips directly into the panel enclosure alongside other S200 breakers, contactors, and terminal blocks. The 3-pole body occupies three modular 17.5 mm widths — 52.5 mm total rail space. No separate adapter or base required.","metaTitle":"S203-K8 ABB S200 Series 8A 3-Pole K-Curve MCB, 480Y/277V, 6","metaDescription":"ABB S203-K8 S200 series miniature circuit breaker, 8A, 3-pole, K-curve, 480Y/277V AC, 6 kAIC. UL 1077 supplemental protector. Current lifecycle. Available to order against RFQ.","metaKeywords":null},"attributes":{"series":null,"packageCase":null,"mountingType":null,"rohsStatus":null,"productStatus":null,"categoryPath":["3-Pole MCB (DIN Rail)"],"specifications":{"Amps":"8","Type":"Trip Curve K","Poles":"3","title":"S203-K8","Mounting":"DIN Rail","Volts AC":"480","description":"8A, 480Y/277V, 6 kAIC, B-Curve, UL 1077 CB|Miniature Circuit Breaker, 8 Amps, 480Y/277V AC. K - Curve. 6 kAIC. S200 Series. Supplemental Protectors. UL 1077, CSA 22.2.","lifecycle_stage":"current","Interrupt Rating AC":"6 kA"}},"commercial":{"minOrderQty":null,"leadTime":null,"referencePrice":"$13.97","stockQuantity":0,"priceTiers":null},"links":{"datasheetUrl":"https://cdn.aoctrl.com/1b888e9d473400bd32917551d1de57a0.pdf","sourceUrl":null},"ai":{"faq":[{"question":"Where can I buy the S203-K8 and get a price?","answer":"The S203-K8 is sourced and quoted to order against an RFQ through independent distribution. Availability and current pricing are confirmed at quote time — submit an RFQ for a firm price and lead time."},{"question":"What does the K-curve mean on the S203-K8?","answer":"The K-curve provides a magnetic trip threshold of 8–12× rated current (64–96 A for this 8 A breaker), designed to handle the inrush from inductive loads such as small motors, transformers, and solenoids without nuisance tripping."},{"question":"What compliance documentation does ABB provide for the S203-K8?","answer":"The S203-K8 is UL 1077 listed and CSA 22.2 certified as a supplemental protector. Standard documentation includes the UL/CSA listing mark on the device; RoHS and REACH compliance declarations are available through ABB's documentation portal."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"icboms-matrix-langgraph","citationUrl":"https://aoctrl.com/abb/S203-K8","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-K8 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}}