{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"S803S-B20","brand":"ABB","brandSlug":"abb","productSlug":"S803S-B20","canonicalUrl":"https://aoctrl.com/abb/S803S-B20","factsUrl":"https://aoctrl.com/api/mcp/products/S803S-B20","rawCanonicalId":null},"summary":{"shortDescription":"S803S-B20, ABB S800S series, 3-pole miniature circuit breaker, 20 A, Trip Curve B, 690 VAC, DIN rail mount.","salesMarkdown":"The thermal-magnetic trip mechanism handles overloads via a bimetal strip and short-circuits via an electromechanical solenoid, so you get both time-delayed and instantaneous protection in one package. ## Trip Curve B — what that means for your panel Curve B trips at 3 to 5 times rated current (60–100 A for this 20 A breaker). That's a narrow instantaneous band, so it clears low-level faults fast but avoids nuisance tripping on small motor starts or capacitive loads. If your circuit has higher inrush — say a larger motor or a bank of switching supplies — you'd want Curve C (5–10× In) or Curve D (10–20× In). The S800S family includes those variants, but this B-curve unit is the right call for general-purpose distribution where the loads are mostly resistive or have modest inrush. ## Panel integration The 3-pole footprint matches the S800S family's modular width — roughly 3 × 17.5 mm per pole. The toggle handle and clear status window give a quick visual on the trip state without opening the panel door.","metaTitle":"S803S-B20 Circuit Breaker, 20A, 3-Pole, Curve B, DIN Rail","metaDescription":"S803S-B20 20A 3-pole Trip Curve B MCB, 690 VAC, DIN rail mount. Current lifecycle. 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":"20","Type":"Trip Curve B","Poles":"3","title":"S803S-B20","Mounting":"DIN Rail","Volts AC":"690","description":"Circuit Breaker, 20A, 3P|Circuit Breaker, 20 Amp, 3-Pole, Tripping Characteristic: B, Thermal Tripping Mechanism for Overload Protection, Electromechanic Tripping Mechanism for Short Circuit Protection, Rated Operational Voltage: 400/690 Volts AC, 375 Volts DC, Rated Frequency: 50/60 Hz","lifecycle_stage":"current"}},"commercial":{"minOrderQty":null,"leadTime":null,"referencePrice":null,"stockQuantity":0,"priceTiers":null},"links":{"datasheetUrl":"https://cdn.aoctrl.com/cd53bd7c709f7c51d87e85ca45487b06.pdf","sourceUrl":null},"ai":{"faq":[{"question":"What is S803S-B20's listed amps (20) on this component line?","answer":"The S803S-B20 is rated at 20 A continuous, with a Trip Curve B instantaneous trip threshold of 3 to 5 times rated current (60–100 A)."},{"question":"Will S803S-B20 drop into a panel that was specified around S803S-D63 without rewiring?","answer":"No — the S803S-D63 is a 63 A, Curve D breaker; the S803S-B20 is 20 A, Curve B. Both are 3-pole DIN-rail units from the same S800S family, so the physical footprint and mounting are identical, but the current rating and trip curve are different. You would need to verify the circuit's load and coordination requirements before swapping."},{"question":"Who supplies S803S-B20 and how is it quoted for volume purchases?","answer":"We supply the S803S-B20 through our independent distribution network. Volume pricing and lead time are confirmed at quote time against an RFQ — no stock figures or firm prices are published here."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"icboms-matrix-langgraph","citationUrl":"https://aoctrl.com/abb/S803S-B20","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/S803S-B20 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}}