{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"5SP3820-3","brand":"Siemens","brandSlug":"siemens","productSlug":"5SP3820-3","canonicalUrl":"https://aoctrl.com/siemens/5SP3820-3","factsUrl":"https://aoctrl.com/api/mcp/products/5SP3820-3","rawCanonicalId":null},"summary":{"shortDescription":"Siemens SENTRON miniature circuit breaker, 5SP3820-3, 3-pole, 20 A rated at 400 V AC, E tripping characteristic, 25 kA breaking capacity per EN 60898, 4.5 MW, IP40.","salesMarkdown":"The Siemens 5SP3820-3 is a SENTRON main miniature circuit breaker, 3-pole (3P), rated 20 A at 400 V AC with an E tripping characteristic. The E-curve is a Siemens-specific characteristic that sits between the standard B and C curves — it trips between 2.5 and 4 times rated current, making it a good fit for transformer inrush or motor-start loads where a B curve would nuisance-trip but a C curve might be too slow for short-circuit protection. ## Thermal derating and wire sizing The 20 A rating holds at 30 °C ambient; at 40 °C it derates to 19 A, at 45 °C to 18.5 A, and at 55 °C to 17.5 A (–). The terminals accept solid or stranded conductors from 2.5 mm² up to 50 mm², which covers everything from standard 2.5 mm² lighting circuits up to 50 mm² feeders for sub-distribution. It's a standard SENTRON catalog line, so it's not a niche or legacy part that's hard to find. ## Key specs at a glance for the panel builder Insulation voltage rated 690 V, overvoltage category IV, pollution degree 3 — this is a robust breaker for the main distribution point, not just a final-subcircuit device. Shock resistance tested to 30 g, at least 3 impacts of 11 ms duration. The locking device has an integrated locking slide, lockable by lock, wire seal, or cable ties. Infeed at box terminal, and the supply cord position is any — no orientation restrictions when wiring.","metaTitle":"Siemens 5SP3820-3 SENTRON MCB, 20 A 3P E-Curve, 25 kA","metaDescription":"Siemens 5SP3820-3 SENTRON miniature circuit breaker, 20 A, 3-pole, E characteristic, 25 kA breaking capacity per EN 60898. Sourced to order against RFQ.","metaKeywords":null},"attributes":{"series":null,"packageCase":null,"mountingType":null,"rohsStatus":null,"productStatus":"Active","categoryPath":["1-Pole MCB (DIN Rail)"],"specifications":{"Depth":"76.3 mm","Height":"128 mm","Maximum":"70 °C","Minimum":"-40 °C","Sealable":"Yes","Rated Value":"25 kA","Number Of Poles":"3","Solid / Maximum":"50 mm²","Solid / Minimum":"2.5 mm²","lifecycle_stage":"current","Fastening Method":"standard rail","Saddle Terminals":"Yes","Shock Resistance":"30 g, at least 3 impacts, impact duration 11 ms","Product Brand Name":"SENTRON","Stranded / Maximum":"50 mm²","Stranded / Minimum":"2.5 mm²","Degree Of Pollution":"3","Product Designation":"Miniature circuit breaker","acc. to IEC 81346-2":"F","at AC / rated value":"20 A","protection class IP":"IP40, with connected conductors","Overvoltage Category":"IV","Design Of The Product":"Main miniature circuit breaker","Infeed At Box Terminal":"Yes","Number Of Poles / Note":"3P","acc. to DIN EN 61346-2":"F","at 30 °C / rated value":"20 A","at 40 °C / rated value":"19 A","at 45 °C / rated value":"18.5 A","at 50 °C / rated value":"18 A","at 55 °C / rated value":"17.5 A","Depth / Of The Enclosure":"76.3 mm","Suitability For Operation":"Residential buildings/infrastructure","Design Of The Locking Device":"Integrated locking slide, lockable by means of a lock, wire seal and cable ties","Number Of Modular Width Units":"4.5","Tripping Characteristic Class":"E","acc. to EN 60898 / rated value":"25 kA","Position / Of Power Supply Cord":"Any","Insulation Voltage / Rated Value":"690 V","supply voltage / at AC / rated value":"400 V","Surge Voltage Resistance / Rated Value":"6 kV","Fastening Method / Other Installation / Note":"On standard mounting rail 35 mm acc. to EN 60715","vibration resistance / acc. to IEC 60068-2-6":"2 g, 20 frequency cycles 5 to 150 to 15 Hz","Display Version / For Switch Position Indicator":"OFF = green, ON = red","Mechanical Service Life (Operating Cycles) / Typical":"20 000"}},"commercial":{"minOrderQty":null,"leadTime":null,"referencePrice":null,"priceTiers":null},"links":{"datasheetUrl":null,"sourceUrl":"https://support.industry.siemens.com/webbackend/api/ProductSupport/TechnicalData?language=en&region=cn&productId=282842&mlfb=5SP3820-3","alternativesUrl":"https://aoctrl.com/api/mcp/products/5SP3820-3/alternatives.json"},"ai":{"faq":[{"question":"What is the closest functional second-source to 5SP3820-3 — 5SJ6325-7RC?","answer":"The 5SJ6325-7RC is a different Siemens MCB series (5SJ6) with a different tripping characteristic and breaking capacity. The 5SP3820-3 has an E-curve and 25 kA breaking capacity; the 5SJ6 series typically uses B/C/D curves. They are not drop-in replacements — verify the tripping characteristic and breaking capacity requirements before substituting."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"matrix-langgraph","citationUrl":"https://aoctrl.com/siemens/5SP3820-3","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/5SP3820-3 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}}