{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"5SM3747-4","brand":"Siemens","brandSlug":"siemens","productSlug":"5SM3747-4","canonicalUrl":"https://aoctrl.com/siemens/5SM3747-4","factsUrl":"https://aoctrl.com/api/mcp/products/5SM3747-4","rawCanonicalId":null},"summary":{"shortDescription":"Siemens SENTRON 5SM3747-4, RCCB, Type B, 80 A, 500 mA, 4-pole, short-time delayed, DIN rail mount.","salesMarkdown":"The Siemens 5SM3747-4 is a 4-pole residual current circuit breaker (RCCB) from the SENTRON family, rated 80 A at 40 °C and 45 °C with a 500 mA residual trip current. It's a Type B device — that means it detects smooth DC residual currents in addition to AC and pulsating DC, so it's the right pick for variable-frequency drives, UPS systems, and PV inverters where DC fault currents can flow. The short-time delayed switching function gives it selectivity with downstream RCCBs: it holds through brief inrush or leakage pulses that would nuisance-trip a standard unit. ## Ratings that matter for panel integration The 72 mm width takes up 4 modular units on the rail. Depth is 77 mm, installation depth 70 mm, so it clears a standard 80 mm deep enclosure back wall. IP20 rating applies once the distribution board is installed with conductors connected — that's typical for a panel interior; no special washdown sealing needed. The short-circuit current rating is 10 kA per the device's own withstand, and it's also rated 0.8 kA according to EN 60898 and IEC 61008-1 — that's the standard for RCCB coordination with an upstream MCB or fuse. Overvoltage category III means it's rated for fixed-installation distribution level, not just downstream equipment. ## Thermal derating — don't ignore it The 80 A rating holds up to 45 °C ambient. Above that, it derates: 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 (–).","metaTitle":"Siemens 5SM3747-4 SENTRON RCCB, Type B, 80A, 500mA, 4-Pole","metaDescription":"Siemens 5SM3747-4 SENTRON RCCB, Type B, 80A rated, 500mA trip, 4-pole, short-time delayed. Active production. DIN rail mount. Quoted 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":"-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":"Short-time delayed","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":"3 kA","according to IEC 61008-1 / rated value":"0.8 kA","Switching Function / Short-Term Delayed":"Yes","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=169294&mlfb=5SM3747-4","alternativesUrl":"https://aoctrl.com/api/mcp/products/5SM3747-4/alternatives.json"},"ai":{"faq":[{"question":"What is the closest functional second-source to 5SM3747-4?","answer":"The 5SL4363-7 is a peer from the same SENTRON family, but it's a different pole count and rating — verify your specific voltage and current requirements before substituting. The 5SM3747-4 is a 4-pole Type B 80 A / 500 mA short-time delayed RCCB; the 5SL series are MCBs, not RCCBs, so they serve a different protection function."},{"question":"Will 5SM3747-4 drop into a panel specified around 5SL4363-7 without rewiring?","answer":"No — the 5SM3747-4 is an RCCB (residual current protection) while the 5SL4363-7 is an MCB (overcurrent protection). They serve different functions and are not drop-in interchangeable. You'd need to redesign the protection scheme."},{"question":"What compliance documentation does Siemens provide for 5SM3747-4?","answer":"The device carries ratings per EN 60898 and IEC 61008-1, and is silicon-free. Standard Siemens SENTRON documentation includes CE declaration and RoHS/REACH compliance data sheets available on request."},{"question":"How do I get current pricing and availability for 5SM3747-4?","answer":"Submit an RFQ through this listing. Availability and current pricing are confirmed at quote time through independent distribution channels."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"matrix-langgraph","citationUrl":"https://aoctrl.com/siemens/5SM3747-4","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/5SM3747-4 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}}