{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"5SM3747-5","brand":"Siemens","brandSlug":"siemens","productSlug":"5SM3747-5","canonicalUrl":"https://aoctrl.com/siemens/5SM3747-5","factsUrl":"https://aoctrl.com/api/mcp/products/5SM3747-5","rawCanonicalId":null},"summary":{"shortDescription":"Siemens SENTRON RCCB, selective, Type B, 4-pole, 80 A rated, 500 mA trip, 10 kA SCCR, DIN rail mount.","salesMarkdown":"The Siemens SENTRON 5SM3747-5 is a 4-pole selective RCCB (residual current circuit breaker) rated 80 A at 40 °C and 45 °C, with a 500 mA residual trip threshold. The Type B characteristic means it detects smooth DC fault currents and mixed-frequency AC/DC residuals — essential on drives, UPS, or PV circuits where standard AC/DC-sensitive (Type A) devices would miss a fault. The selective (S-type) design introduces a deliberate short-time delay so that downstream RCCBs trip first, keeping this unit as the main switch — no nuisance blackout of the whole panel for a downstream ground leak. Short-circuit withstand is 10 kA per IEC 61008-1 (0.8 kA per EN 60898), which covers most sub-distribution boards fed from a transformer of typical impedance. The I²t let-through is rated 70 000 A²·s, so coordination with an upstream MCCB or fuse is straightforward — the energy the RCCB passes is bounded enough to protect the busbar and downstream terminals. ## Derating and thermal behaviour Above that, derate linearly: 76.8 A at 50 °C, 73.6 A at 55 °C, 70.4 A at 60 °C, 67.2 A at 65 °C, and 64 A at 70 °C. Snap-on DIN rail (REG) mount, 4 MW width (72 mm), installation depth 70 mm, overall depth 77 mm. Fits any standard DIN-rail enclosure; the top or bottom feed works, and the SIGRES function remains live even in the off state when fed from the bottom.","metaTitle":"Siemens SENTRON 5SM3747-5 RCCB, 4P, 80 A, Type B, Selective","metaDescription":"Siemens SENTRON 5SM3747-5 4-pole RCCB, 80 A rated, Type B residual current, selective design, 10 kA SCCR, DIN rail mount. Sourced to order against RFQ.","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","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","Product Designation":"RCCB","at AC / rated value":"80 A","protection class IP":"IP20, if the distribution board is installed, with connected conductors","Overvoltage Category":"III","Design Of The Product":"Selective","Residual Current Type":"B","I2t value / permissible":"70 000 A²·s","at 40 °C / rated value":"80 A","at 45 °C / rated value":"80 A","at 50 °C / rated value":"76.8 A","at 55 °C / rated value":"73.6 A","at 60 °C / rated value":"70.4 A","at 65 °C / rated value":"67.2 A","at 70 °C / rated value":"64 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","For Testing Equipment / Minimum":"195 V","Position / Of Power Supply Cord":"Top or bottom (bottom for SIGRES function also in switched-off state)","Let-Through Current / Permissible":"7 500 kA","Tripping Fault Current / Rated Value":"500 mA","Supply Voltage Frequency / Rated Value":"50 Hz","Surge Current Resistance / Rated Value":"5 kA","according to IEC 61008-1 / rated value":"0.8 kA","Switching Function / Short-Term Delayed":"No","size of installation devices / acc. to DIN 43880":"1","Mechanical Service Life (Operating 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=280734&mlfb=5SM3747-5","alternativesUrl":"https://aoctrl.com/api/mcp/products/5SM3747-5/alternatives.json"},"ai":{"faq":[{"question":"Where can I buy 5SM3747-5 and how do I get a price?","answer":"Sourced to order against an RFQ through independent distribution. Submit an RFQ for current availability and pricing."},{"question":"What is the closest functional second-source to 5SM3747-5?","answer":"The 5SL4363-7 is a 4-pole RCCB from the same SENTRON family, but it is a non-selective (instantaneous) Type A device rated 63 A — not a direct form-fit-function replacement for the selective Type B 80 A 5SM3747-5. Verify the selectivity, residual type, and current rating before substituting."},{"question":"What is 5SM3747-5's listed depth?","answer":"Overall depth is 77 mm; installation depth is 70 mm."},{"question":"What is 5SM3747-5's listed width?","answer":"Width is 72 mm, corresponding to 4 modular width units (MW)."},{"question":"Will 5SM3747-5 drop into a panel specified around 5SL4363-7 without rewiring?","answer":"Both are 4-pole DIN-rail RCCBs in the SENTRON family, so the physical footprint (4 MW) and mounting are identical. However, the 5SM3747-5 is selective (time-delayed) and Type B, while the 5SL4363-7 is instantaneous and Type A — the protection coordination and residual current detection differ. Rewiring is not needed, but the protection scheme must be re-evaluated."},{"question":"What compliance documentation does Siemens provide for 5SM3747-5?","answer":"The device is silicon-free and carries ratings per IEC 61008-1 and EN 60898. Standard Siemens declarations (CE, UKCA, RoHS, REACH) are available through the manufacturer's documentation portal."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"matrix-langgraph","citationUrl":"https://aoctrl.com/siemens/5SM3747-5","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/5SM3747-5 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}}