{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"5SM3746-4","brand":"Siemens","brandSlug":"siemens","productSlug":"5SM3746-4","canonicalUrl":"https://aoctrl.com/siemens/5SM3746-4","factsUrl":"https://aoctrl.com/api/mcp/products/5SM3746-4","rawCanonicalId":null},"summary":{"shortDescription":"Siemens SENTRON 5SM3746-4 RCCB, 4-pole, 63 A, Type B, 500 mA, short-time delayed, 10 kA, DIN rail.","salesMarkdown":"The short-time delayed design (selective type) provides coordination with downstream devices, letting fault currents pass briefly to avoid nuisance tripping on transient surges while still clearing persistent ground faults. Rated at 63 A continuous at 40 °C and 45 °C, derating to 60.48 A at 50 °C and 50.4 A at 70 °C — the thermal curve matters if the panel runs hot. The 10 kA short-circuit current rating (SCCR) per IEC 61008-1 gives the fault-clearing capacity at the device terminals; under EN 60898 the rated breaking capacity is 0.8 kA, which is the standard for domestic RCCBs. The Type B characteristic detects AC, pulsating DC, and smooth DC residual currents up to 1 kHz — required where variable-speed drives, UPS systems, or photovoltaic inverters are on the load side, since those can generate DC fault currents that a Type A or AC device would miss. The 500 mA rated residual operating current (IΔn) is higher than the standard 30 mA for personal protection; this unit is intended for equipment protection or fire prevention in circuits where nuisance tripping from leakage currents (long cable runs, filter capacitors) would be problematic. The short-time delayed switching function (selective RCCB, type S) coordinates with downstream 30 mA RCCBs so that only the faulted branch trips, keeping supply to healthy circuits. The 72 mm width (4 MW) matches the SENTRON modular grid.","metaTitle":"Siemens 5SM3746-4 SENTRON RCCB, 63 A, Type B, 4-Pole, 500 mA","metaDescription":"Siemens SENTRON 5SM3746-4 RCCB, 63 A rated, Type B, 4-pole, 500 mA residual current, 10 kA SCCR, short-time delayed. Current production. 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","Operating Frequency":"50/60 Hz","Product Designation":"RCCB","at AC / rated value":"63 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":"63 A","at 45 °C / rated value":"63 A","at 50 °C / rated value":"60.48 A","at 55 °C / rated value":"57.96 A","at 60 °C / rated value":"55.44 A","at 65 °C / rated value":"52.92 A","at 70 °C / rated value":"50.4 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 (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=320531&mlfb=5SM3746-4","alternativesUrl":"https://aoctrl.com/api/mcp/products/5SM3746-4/alternatives.json"},"ai":{"faq":[{"question":"What is 5SM3746-4 used for?","answer":"It is a 4-pole Type B RCCB rated 63 A / 500 mA, used for equipment protection and fire prevention in circuits with VFDs, UPS, or PV inverters that can generate DC residual currents."},{"question":"Where can I buy 5SM3746-4 and how is it quoted?","answer":"Sourced and quoted to order against an RFQ through independent distribution. Availability and current pricing are confirmed at quote time."},{"question":"Will 5SM3746-4 drop into a panel specified around 5SL4363-7 without rewiring?","answer":"No — 5SL4363-7 is a miniature circuit breaker (MCB), not an RCCB. They serve different protection functions and are not direct substitutes. The 5SM3746-4 occupies the same 4 MW DIN-rail footprint but requires a neutral connection for the residual current sensing circuit."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"matrix-langgraph","citationUrl":"https://aoctrl.com/siemens/5SM3746-4","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/5SM3746-4 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}}