{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"5SM3446-8","brand":"Siemens","brandSlug":"siemens","productSlug":"5SM3446-8","canonicalUrl":"https://aoctrl.com/siemens/5SM3446-8","factsUrl":"https://aoctrl.com/api/mcp/products/5SM3446-8","rawCanonicalId":null},"summary":{"shortDescription":"Siemens SENTRON selective RCCB, 4-pole, 40 A at 45 °C, 100 mA residual current, Type A, 10 kA SCCR, DIN rail mount, IP20.","salesMarkdown":"## Selective RCCB for 400 V AC feeder protection The Siemens 5SM3446-8 is a 4-pole selective RCCB from the SENTRON series, rated at 40 A at both 40 °C and 45 °C ambient, with a 100 mA residual tripping current and Type A waveform sensitivity. Selective design means it introduces a deliberate time delay so that downstream RCCBs trip first, keeping this unit as the backup — critical for feeder coordination in a distribution board where you want the branch, not the main, to clear a ground fault. ## Thermal derating and SCCR headroom Rated 40 A up to 45 °C, then derates linearly to 28 A at 70 °C — a 30 % drop. Short-circuit current rating is 10 kA per IEC 61008-1, with an additional 0.8 kA rating under EN 60898. The 10 kA figure governs the upstream breaker coordination; the 0.8 kA is a conditional rating for the RCCB's own breaking capacity under standard test conditions. Mounts in any position.","metaTitle":"Siemens 5SM3446-8 SENTRON RCCB, 4-pole, 40 A, 100 mA, Type A","metaDescription":"Siemens 5SM3446-8 SENTRON selective RCCB, 4-pole, 40 A rated at 45 °C, 100 mA residual, Type A, 10 kA SCCR, IP20. Sourced to order; RFQ for price and availability.","metaKeywords":null},"attributes":{"series":null,"packageCase":null,"mountingType":null,"rohsStatus":null,"productStatus":null,"categoryPath":["Residual Current Breakers (RCCB/RCBO)"],"specifications":{"Depth":"77 mm","Width":"72 mm","Height":"90 mm","Maximum":"45 °C","Minimum":"-25 °C","Rated Value":"50 Hz","Number Of Poles":"4","lifecycle_stage":"current","Fastening Method":"DIN rail (REG)","Mounting Position":"any","Installation Depth":"70 mm","Product Brand Name":"SENTRON","Maximum Permissible":"75 °C","Minimum Permissible":"-40 °C","Operating Frequency":"50 Hz","Product Designation":"RCCB","acc. to IEC 81346-2":"F","protection class IP":"IP20, if the distribution board is installed, with connected conductors","Overvoltage Category":"III","Design Of The Product":"Selective","Residual Current Type":"A","acc. to DIN EN 61346-2":"F","I2t value / permissible":"70 000 A²·s","at 40 °C / rated value":"40 A","at 45 °C / rated value":"40 A","at 50 °C / rated value":"37.6 A","at 55 °C / rated value":"35.2 A","at 60 °C / rated value":"32.8 A","at 65 °C / rated value":"30.4 A","at 70 °C / rated value":"28 A","Short-Circuit Current Rating":"10 kA","Number Of Modular Width Units":"4","Product Feature / Silicon-Free":"Yes","acc. to EN 60898 / rated value":"0.8 kA","Position / Of Power Supply Cord":"top or bottom","Let-Through Current / Permissible":"7 500 kA","Tripping Fault Current / Rated Value":"100 mA","supply voltage / at AC / rated value":"400 V","Surge Current Resistance / Rated Value":"5 kA","according to IEC 61008-1 / rated value":"0.8 kA","Switching Function / Short-Term Delayed":"No","Touch Protection Against Electrical Shock":"Finger and back-of-hand safe","operational current / at AC / rated value":"63 A","Supply Voltage / For Testing Equipment / Minimum":"100 V","size of installation devices / acc. to DIN 43880":"1","Mechanical Service Life (Switching Cycles) / Typical":"10 000"}},"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=376234&mlfb=5SM3446-8","alternativesUrl":"https://aoctrl.com/api/mcp/products/5SM3446-8/alternatives.json"},"ai":{"faq":[{"question":"What is the rated residual current of 5SM3446-8?","answer":"The tripping fault current is rated at 100 mA, Type A (sensitive to AC and pulsating DC residual currents)."},{"question":"What is the SCCR of 5SM3446-8?","answer":"The short-circuit current rating is 10 kA per IEC 61008-1, with an additional 0.8 kA rating under EN 60898."},{"question":"Will 5SM3446-8 drop into a panel that was specified around 5SJ6325-7RC without rewiring?","answer":"Both are 4-pole DIN-rail RCCBs, but the 5SJ6325-7RC is a standard (non-selective) Type A unit; the 5SM3446-8 is selective with a time delay. Footprint is the same 4 MW width, but the selective delay changes coordination — verify the upstream breaker's time-current curve before swapping."},{"question":"How do I get current pricing and availability for 5SM3446-8?","answer":"Submit an RFQ through the storefront. Pricing and stock are confirmed at quote time; the part is sourced to order through independent distribution."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"matrix-langgraph","citationUrl":"https://aoctrl.com/siemens/5SM3446-8","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/5SM3446-8 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}}