{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"5SM3446-0","brand":"Siemens","brandSlug":"siemens","productSlug":"5SM3446-0","canonicalUrl":"https://aoctrl.com/siemens/5SM3446-0","factsUrl":"https://aoctrl.com/api/mcp/products/5SM3446-0","rawCanonicalId":null},"summary":{"shortDescription":"Siemens SENTRON RCCB, 4-pole, 63 A at 45 °C, 400 V AC, 50 Hz, instantaneous AC type, 10 kA SCCR, DIN rail mount, IP20.","salesMarkdown":"## What it is and what it does The Siemens SENTRON 5SM3446-0 is a 4-pole residual current circuit breaker (RCCB) rated 63 A at 45 °C on a 400 V AC, 50 Hz supply. It trips instantaneously on AC fault currents — no intentional delay, so it's the first device to open on a ground fault in a distribution board. The 10 kA short-circuit current rating (SCCR) means it can safely interrupt a fault up to that level without welding contacts or cascading damage upstream. ## Mounting and panel fit Snaps onto a DIN rail (REG profile) and occupies 4 width units (72 mm wide). Installation depth is 70 mm; overall depth is 77 mm. Mounting position is unrestricted — any orientation works. Supply can enter from top or bottom. IP20 with the distribution board installed and conductors connected — standard for enclosed panel use, not for wet or outdoor locations. ## Thermal derating and real-world current At 40 °C and 45 °C the device holds its full 63 A rating. Above that it derates linearly: 59.22 A at 50 °C, 55.44 A at 55 °C, 51.66 A at 60 °C, 47.88 A at 65 °C, and 44.1 A at 70 °C. If the panel ambient runs hot — say a crowded enclosure near a drive — size the load to the derated figure, not the nameplate 63 A. Maximum power loss is 9 W.","metaTitle":"Siemens SENTRON 5SM3446-0 RCCB, 4P, 63 A, 400 V AC, 10 kA","metaDescription":"Siemens SENTRON 5SM3446-0 RCCB, 4-pole, 63 A at 45 °C, 400 V AC, 10 kA SCCR, instantaneous AC type. DIN rail mount, IP20. Current production; sourced to order.","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":"-5 °C","Rated Value":"50 Hz","Mounting type":"DIN rail (REG)","Number Of Poles":"4","lifecycle_stage":"current","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","Protection class IP":"IP20, if the distribution board is installed, with connected conductors","at AC / rated value":"400 V","Overvoltage Category":"III","Design of the product":"Instantaneous","Number Of Width Units":"4","Type of fault current":"AC","at 40 °C / rated value":"63 A","at 45 °C / rated value":"63 A","at 50 °C / rated value":"59.22 A","at 55 °C / rated value":"55.44 A","at 60 °C / rated value":"51.66 A","at 65 °C / rated value":"47.88 A","at 70 °C / rated value":"44.1 A","power loss [W] / maximum":"9 W","Short-circuit current rating":"10 kA","Product Feature / Silicon-Free":"Yes","acc. to EN 60898 / rated value":"0.8 kA","For Testing Equipment / Minimum":"100 V","Position / of power supply cord":"top or bottom","Protection against electrical shock":"Finger and back-of-hand safe","according to IEC 61008-1 / rated value":"0.8 kA","Operating current / at AC / rated value":"63 A","Reference code / acc. to DIN EN 81346-2":"F","Switching function / short-term delayed":"No","Tripping residual current / rated value":"100 mA","reference code / acc. to DIN EN 61346-2":"F","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=65494&mlfb=5SM3446-0","alternativesUrl":"https://aoctrl.com/api/mcp/products/5SM3446-0/alternatives.json"},"ai":{"faq":[{"question":"How do I get current pricing and availability for 5SM3446-0?","answer":"Submit an RFQ through this listing. The part is sourced to order via independent distribution; pricing and stock levels are confirmed at quote time."},{"question":"What is 5SM3446-0's listed depth (77 mm) on this component line?","answer":"The overall depth is 77 mm; the installation depth (into the panel) is 70 mm. Width is 72 mm (4 width units), height is 90 mm."},{"question":"Will 5SM3446-0 drop into a panel that was specified around 5SU9354-7KK16 without rewiring?","answer":"Both are 4-pole RCCBs on a DIN rail footprint, but the 5SU9354-7KK16 is a different SENTRON variant with its own ratings. The 5SM3446-0 is an instantaneous AC type; verify the peer's fault type and delay characteristics before swapping — the physical rail fit is the same, but the protection curve may differ."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"matrix-langgraph","citationUrl":"https://aoctrl.com/siemens/5SM3446-0","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/5SM3446-0 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}}