{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"S203-B10","brand":"ABB","brandSlug":"abb","productSlug":"S203-B10","canonicalUrl":"https://aoctrl.com/abb/S203-B10","factsUrl":"https://aoctrl.com/api/mcp/products/S203-B10","rawCanonicalId":null},"summary":{"shortDescription":"ABB S203-B10, 3-pole MCB, 10 A, Trip Curve B, 277 VAC, 10 kA interrupting rating, DIN rail mount.","salesMarkdown":"The ABB S203-B10 is a 3-pole miniature circuit breaker rated for 10 A with a Trip Curve B characteristic, meaning it trips between 3 and 5 times rated current — suited for resistive or lightly inductive loads where short inrush is minimal. It interrupts faults up to 10 kA at 277 VAC, giving you enough SCCR headroom for most distribution sub-panels without cascading upstream. ## Panel fit and sourcing The 3-pole format occupies three module widths, so factor that into your enclosure fill count. ## Curve B vs Curve C — the real difference The S203-B10 uses Trip Curve B (3–5× In instantaneous trip), while the sibling S203-C10 uses Curve C (5–10× In). If your circuit has motor or transformer inrush that briefly exceeds 5× rated current, the B curve may nuisance-trip — that is the one case where stepping to the C10 avoids a callout. For resistive loads like heaters or lighting, the B curve gives faster fault clearing, which is the better choice.","metaTitle":"S203-B10 MCB, 3P, 10A, Curve B, 10 kA","metaDescription":"S203-B10 miniature circuit breaker, 3-pole, 10 A, Trip Curve B, 277 VAC, 10 kA interrupting rating. Current lifecycle stage. Sourced 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":"10","Type":"Trip Curve B","Poles":"3","title":"S203-B10","Mounting":"DIN Rail","Volts AC":"277","description":"Mcb 3p B 10a 480y/277 Supp|Mcb 3p B 10a 480y/277 Supp","lifecycle_stage":"current","Interrupt Rating AC":"10 kA"}},"commercial":{"minOrderQty":null,"leadTime":null,"referencePrice":"$115.14","stockQuantity":0,"priceTiers":null},"links":{"datasheetUrl":"https://cdn.aoctrl.com/585145f9e1747680e85043925d3378ee.pdf","sourceUrl":null},"ai":{"faq":[{"question":"Where can I buy S203-B10 and get a price?","answer":"Submit an RFQ through this listing. The part is sourced to order through independent distribution; availability and current pricing are confirmed at quote time."},{"question":"Will S203-B10 drop into a panel specified for S203-C10 without rewiring?","answer":"Yes — same 3-pole DIN-rail footprint, same 10 A rating, same 10 kA interrupting capacity at 277 VAC. The only difference is the trip curve: B vs C. No rewiring needed, but check that your load inrush stays under 5× rated current to avoid nuisance trips on the B curve."},{"question":"What is S203-B10's listed amps?","answer":"10 A."},{"question":"What is S203-B10's trip curve type?","answer":"Trip Curve B — instantaneous trip between 3 and 5 times rated current."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"icboms-matrix-langgraph","citationUrl":"https://aoctrl.com/abb/S203-B10","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-B10 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}}