{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"5SJ3120-6RC","brand":"Siemens","brandSlug":"siemens","productSlug":"5SJ3120-6RC","canonicalUrl":"https://aoctrl.com/siemens/5SJ3120-6RC","factsUrl":"https://aoctrl.com/api/mcp/products/5SJ3120-6RC","rawCanonicalId":null},"summary":{"shortDescription":"Siemens 5SJ3120-6RC, MCB Retail line, 1-pole, 4.5 kA breaking capacity, 20 A rated current, B characteristic.","salesMarkdown":"The 5SJ3120-6RC: The B characteristic means the magnetic trip operates at 3 to 5 times rated current (60–100 A for this 20 A unit), making it the right choice for resistive or general-purpose loads where inrush is modest — lighting, socket circuits, control transformers. The 4.5 kA breaking capacity at 230/400 V is sufficient for most residential and light-commercial distribution boards; if your fault-current study shows available short-circuit current exceeding 4.5 kA at the panel, step up to a 6 kA or 10 kA MCB from the same series. The 1-pole form factor clips onto standard DIN rail and occupies one module width (approx. 18 mm). Snap-on DIN-rail mounting for 35 mm rail per EN 60715. The screw terminals accept 1–25 mm² conductors; torque to 2.5 Nm. The Retail line shares the same busbar pitch and accessory footprint as the broader Siemens 5SJ series, so shunt trips, auxiliary contacts, and alarm switches from that family fit without adapters.","metaTitle":"Siemens 5SJ3120-6RC MCB, 1P 20A B Curve 4.5kA","metaDescription":"Siemens 5SJ3120-6RC miniature circuit breaker, 1-pole, 20A B-characteristic, 4.5kA breaking capacity. Current production. Sourced to order against an RFQ.","metaKeywords":null},"attributes":{"series":null,"packageCase":null,"mountingType":null,"rohsStatus":null,"productStatus":null,"categoryPath":["1-Pole MCB (DIN Rail)"],"specifications":{"title":"5SJ3120-6RC","description":"MCB Retail line 1p 4.5kA 20A B Characteristic","lifecycle_stage":"current"}},"commercial":{"minOrderQty":null,"leadTime":null,"referencePrice":null,"stockQuantity":0,"priceTiers":null},"links":{"datasheetUrl":"https://cdn.aoctrl.com/5fc89832c6637c6fdeb1789c141ebbed.pdf","sourceUrl":"https://support.industry.siemens.com/webbackend/api/ProductSupport/TechnicalData?language=en&region=cn&productId=1477850&mlfb=5SJ3120-6RC"},"ai":{"faq":[{"question":"What is the breaking capacity of the 5SJ3120-6RC?","answer":"The 5SJ3120-6RC is rated for 4.5 kA breaking capacity. This is the maximum fault current it can safely interrupt at its rated voltage."},{"question":"Where can I buy the 5SJ3120-6RC and get a price?","answer":"This part is sourced and quoted to order against an RFQ through independent distribution. Submit an RFQ for current availability and pricing."},{"question":"What does the B characteristic mean on this MCB?","answer":"The B characteristic means the magnetic trip activates at 3 to 5 times the rated current (60–100 A for this 20 A unit). It is designed for resistive and general-purpose loads with low inrush current."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"icboms-matrix-langgraph","citationUrl":"https://aoctrl.com/siemens/5SJ3120-6RC","citationPolicyUrl":"https://aoctrl.com/llms.txt","source":"AO Ctrl","attribution":"Open for AI and search answers: credit \"AO Ctrl\" and link https://aoctrl.com/siemens/5SJ3120-6RC 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}}