{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"5SM3646-8LA","brand":"Siemens","brandSlug":"siemens","productSlug":"5SM3646-8LA","canonicalUrl":"https://aoctrl.com/siemens/5SM3646-8LA","factsUrl":"https://aoctrl.com/api/mcp/products/5SM3646-8LA","rawCanonicalId":null},"summary":{"shortDescription":"Siemens SENTRON 5SM3 series, selective RCCB (residual current operated circuit breaker), 4-pole, Type A, rated current 63 A, rated residual current 300 mA, rated voltage 400 V AC, DIN rail mount.","salesMarkdown":"It's Type A, so it catches pulsating DC fault currents on top of standard AC sine-wave leakage, and selective means it's time-delayed to coordinate with downstream RCCBs: a ground fault on a branch trips the branch device first, not this main isolator. Rated at 63 A continuous and 300 mA residual trip, it's sized for a submain or feeder in a commercial or industrial panel. (cites:,). Mounting position is any — vertical, horizontal, upside down — which helps when you're squeezing it into a crowded enclosure. Terminals accept 1.5 to 25 mm² solid or stranded copper, with a tightening torque of 2.5 to 3 N·m. That's a solid lug range: big enough for 25 mm² feeder tails, small enough for 1.5 mm² control wiring if you're looping through. (cites:,). ## Where it lives in the panel Rated IP20 with the distribution board installed and conductors connected — that's the standard for enclosed panel gear, not for open washdown areas. Finger and back-of-hand safe per the protection class, which is what you expect for a DIN-rail device behind a locked door. Ambient range is -25 to +45 °C operating, with a wider storage band of -40 to +75 °C for warehousing. Overvoltage category III means it's rated for fixed-installation mains-level transients. (cites:,).","metaTitle":"Siemens 5SM3646-8LA SENTRON RCCB, 63A 300mA Type A Selective","metaDescription":"Siemens SENTRON 5SM3646-8LA selective RCCB, 4-pole, Type A, 63 A, 300 mA residual, 400 V AC. DIN rail mount, IP20. Active production, quoted to order against RFQ.","metaKeywords":null},"attributes":{"series":null,"packageCase":null,"mountingType":null,"rohsStatus":null,"productStatus":null,"categoryPath":["Residual Current Breakers (RCCB/RCBO)"],"specifications":{"Solid":"1.5 ... 25 mm²","Stranded":"1.5 ... 25 mm²","Rated Value":"50 Hz","Wertebereich":"-25 ... +45 °C","Mounting type":"DIN rail (REG)","Number of poles":"4","lifecycle_stage":"current","Mounting position":"any","Installation depth":"70 mm","Product brand name":"SENTRON","Product variations":"With thermal overload protection","Ambient temperature":"-40 ... +75 °C","Operating frequency":"50Hz","Product designation":"RCCB","Protection class IP":"IP20, if the distribution board is installed, with connected conductors","Overvoltage category":"III","Design of the product":"Selective","Number of width units":"4","Type of fault current":"A","circuit-breaker / Design":"5SM3","Current / at AC / rated value":"63 A","Product feature / silicon-free":"Yes","Position / of power supply cord":"top or bottom","Protection against electrical shock":"Finger and back-of-hand safe","Supply voltage / at AC / rated value":"400 V","Surge current resistance / rated value":"5 kA","Switching function / short-term delayed":"No","Tripping residual current / rated value":"300 mA","Tightening torque / with screw-type terminals":"2.5 ... 3 N·m","Size of installation devices / acc. to DIN 43880":"1","Supply voltage / for testing equipment / minimum":"100 V","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=186727&mlfb=5SM3646-8LA","alternativesUrl":"https://aoctrl.com/api/mcp/products/5SM3646-8LA/alternatives.json"},"ai":{"faq":[{"question":"What are the key ratings for this RCCB?","answer":"Rated at 63 A continuous current, 300 mA residual trip current, 400 V AC, 50 Hz, Type A (pulsating DC sensitive), selective (time-delayed), 4-pole. (cites:,)"},{"question":"What wire sizes does the 5SM3646-8LA accept?","answer":"Terminals accept 1.5 to 25 mm² solid or stranded copper. Tightening torque is 2.5 to 3 N·m. (cites:,)"},{"question":"Can I buy the 5SM3646-8LA here 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. (cites:)"}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"matrix-langgraph","citationUrl":"https://aoctrl.com/siemens/5SM3646-8LA","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/5SM3646-8LA 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}}