{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"5SU1674-8EK81","brand":"Siemens","brandSlug":"siemens","productSlug":"5SU1674-8EK81","canonicalUrl":"https://aoctrl.com/siemens/5SU1674-8EK81","factsUrl":"https://aoctrl.com/api/mcp/products/5SU1674-8EK81","rawCanonicalId":null},"summary":{"shortDescription":"Siemens SENTRON 5SU1674-8EK81, selective RCBO, 4-pole, 100 A rated, 300 mA residual, Type B+, 10 kA breaking capacity, 11 MWU.","salesMarkdown":"## Selectivity and the Type B+ residual The 'selective' design (S-type) means this RCBO introduces a deliberate time delay on the residual trip, so it lets a downstream RCD clear first during a ground fault. That buys you discrimination in a multi-level distribution board — a nuisance trip on a sub-panel doesn't drop the whole feeder. Type B+ residual detection covers AC, pulsating DC, smooth DC, and high-frequency AC components up to 20 kHz, which is what you need when variable-speed drives, UPS systems, or EV chargers are on the load side. Standard Type A units will miss smooth DC or high-frequency leakage; the B+ catches it and trips at 300 mA. ## Thermal derating in the panel At 40 °C it derates to 92.5 A, at 50 °C to 85 A, and at 60 °C to 77 A. If this RCBO sits in a crowded 11-MWU (198 mm wide) section of a distribution board with other heat sources, you need to check the actual enclosure ambient against the derating curve — the tabulated values are the maximum continuous current at each temperature, not a suggestion. The unit is IP20 once installed with conductors connected; that's standard for a distribution board interior, but it's not rated for wet or dusty environments. Supply enters from top or bottom.","metaTitle":"Siemens 5SU1674-8EK81 SENTRON RCBO, 100 A, 300 mA, Type B+,","metaDescription":"Siemens 5SU1674-8EK81 SENTRON selective RCBO, 100 A rated, 300 mA residual, Type B+, 4-pole, 10 kA breaking capacity. Quoted to order against RFQ.","metaKeywords":null},"attributes":{"series":null,"packageCase":null,"mountingType":null,"rohsStatus":null,"productStatus":"Active","categoryPath":["Residual Current Breakers (RCCB/RCBO)"],"specifications":{"Depth":"77 mm","Width":"198 mm","Height":"90 mm","Maximum":"75 °C","Minimum":"-40 °C","Halogen-Free":"Yes","Silicon-Free":"Yes","Number Of Poles":"4","lifecycle_stage":"current","Mounting Position":"any","Installation Depth":"70 mm","Product Brand Name":"SENTRON","Degree Of Pollution":"2","Operating Frequency":"50/60 Hz","Product Designation":"RCBO","acc. to IEC 81346-2":"F","at AC / rated value":"100 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+","Number Of Poles / Note":"4P","acc. to DIN EN 61346-2":"F","Energy Limitation Class":"3","Weight / With Packaging":"2 078 g","at 30 °C / rated value":"100 A","at 40 °C / rated value":"92.5 A","at 45 °C / rated value":"89 A","at 50 °C / rated value":"85 A","at 55 °C / rated value":"81 A","at 60 °C / rated value":"77 A","Number Of Modular Width Units":"11","Tripping Characteristic Class":"D","acc. to EN 60898 / rated value":"10 kA","For Testing Equipment / Minimum":"100 V","Position / Of Power Supply Cord":"Either top or bottom","Number Of Poles / With Protection":"4","acc. to IEC 60947-2 / rated value":"10 kA","Product Feature / Touch Protection":"Yes","Tripping Fault Current / Rated Value":"300 mA","Supply Voltage Frequency / Rated Value":"50 Hz","Influence Of The Surrounding Temperature":"Max. 95% humidity","Surge Current Resistance / At (8/20) μS":"5 kA","Product Function / Neutral Conductor Switching":"Yes","Mechanical Service Life (Operating Cycles) / Typical":"10 000"}},"commercial":{"minOrderQty":null,"leadTime":null,"referencePrice":null,"priceTiers":null},"links":{"datasheetUrl":"https://cdn.aoctrl.com/e39ebec1089bed85635ad0ff48c9b314.pdf","sourceUrl":"https://support.industry.siemens.com/webbackend/api/ProductSupport/TechnicalData?language=en&region=cn&productId=71368&mlfb=5SU1674-8EK81","alternativesUrl":"https://aoctrl.com/api/mcp/products/5SU1674-8EK81/alternatives.json"},"ai":{"faq":[{"question":"What is the difference between this RCBO and a standard 5SL series MCB?","answer":"The 5SU1674-8EK81 is a combined overcurrent and residual current device (RCBO), while the 5SL series are MCBs only. This unit adds Type B+ residual protection at 300 mA and a selective time delay, so it provides ground-fault protection that a bare MCB cannot. The 5SL would need a separate RCD upstream."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"matrix-langgraph","citationUrl":"https://aoctrl.com/siemens/5SU1674-8EK81","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/5SU1674-8EK81 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}}