{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"5SM3646-0LB","brand":"Siemens","brandSlug":"siemens","productSlug":"5SM3646-0LB","canonicalUrl":"https://aoctrl.com/siemens/5SM3646-0LB","factsUrl":"https://aoctrl.com/api/mcp/products/5SM3646-0LB","rawCanonicalId":null},"summary":{"shortDescription":"Siemens SENTRON 5SM3 series, 5SM3646-0LB, 4-pole RCCB, type AC, 63 A, 300 mA, 400 V AC, instantaneous, DIN rail mount.","salesMarkdown":"The 5SM3646-0LB: It is an instantaneous (non-delayed) type, meaning it trips without intentional time delay on a residual fault. That makes it unsuitable for selective coordination with downstream RCDs unless the downstream devices are short-time-delayed or have a lower threshold. The 1 kA surge current resistance (8/20 µs waveform) is standard for this class — it will survive typical lightning-induced transients on a building supply without nuisance tripping or damage. Snaps onto DIN rail (REG profile), occupies 4 width units (about 72 mm at 18 mm per unit). Installation depth is 70 mm, which fits standard distribution board enclosures. Mounting position is unrestricted — vertical, horizontal, or inverted all work. IP20 protection applies once installed with conductors connected — so it is rated for indoor, dry-location use inside a distribution board. ## Environmental limits and service life Rated for ambient temperatures from -5 °C to 45 °C during operation. The 45 °C maximum operating limit means the breaker is fine in a ventilated panel in most climates, but if the enclosure is in direct sun or next to heat sources, you need to check internal temperature rise. The finger and back-of-hand safe protection (per IPXXB) means the terminals are shielded against accidental contact during wiring — a standard safety feature on modern DIN-rail devices.","metaTitle":"Siemens 5SM3646-0LB SENTRON RCCB, 4P, 63A, 300mA, 400V AC","metaDescription":"Siemens SENTRON 5SM3646-0LB 4-pole RCCB, type AC, 63 A rated current, 300 mA residual, 400 V AC. Current lifecycle stage. 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":{"Maximum":"45 °C","Minimum":"-5 °C","Rated Value":"50 Hz","Mounting type":"DIN rail (REG)","Number of poles":"4","lifecycle_stage":"current","Mounting position":"any","Installation depth":"70 mm","Product brand name":"SENTRON","Maximum Permissible":"75 °C","Minimum Permissible":"-40 °C","Operating frequency":"50Hz","Product designation":"RCCB","Protection class IP":"IP20, if the distribution board is installed, with connected conductors","at AC / rated value":"400 V","Overvoltage category":"III","Design of the product":"Instantaneous","Number of width units":"4","Type of fault current":"AC","circuit-breaker / Design":"5SM3","Current / at AC / rated value":"63 A","Product feature / silicon-free":"Yes","For Testing Equipment / Minimum":"100 V","Position / of power supply cord":"top or bottom","Protection against electrical shock":"Finger and back-of-hand safe","Surge current resistance / rated value":"1 kA","Switching function / short-term delayed":"No","Tripping residual current / rated value":"300 mA","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=412450&mlfb=5SM3646-0LB","alternativesUrl":"https://aoctrl.com/api/mcp/products/5SM3646-0LB/alternatives.json"},"ai":{"faq":[{"question":"Will the 5SM3646-0LB drop into a panel specified for the 5SU9304-1KK32?","answer":"No — the 5SU9304-1KK32 is a 2-pole RCBO (RCD + MCB combined) in a single-width module, while the 5SM3646-0LB is a 4-pole standalone RCCB occupying 4 width units. The footprint, wiring scheme, and function are different. They are not drop-in interchangeable."},{"question":"Where can I buy the 5SM3646-0LB and get current pricing?","answer":"This part is available to order. Submit an RFQ for current pricing and delivery lead time — availability is confirmed at quote time through independent distribution channels."},{"question":"What compliance documentation does Siemens provide for this RCCB?","answer":"The SENTRON 5SM3 series carries standard IEC/EN 61008-1 compliance for RCCBs. The silicon-free designation and IP20 rating are documented. For specific certificates (UL, CSA, UKCA, EAC), check the manufacturer's declaration pack — the evidence does not list them individually for this order code."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"matrix-langgraph","citationUrl":"https://aoctrl.com/siemens/5SM3646-0LB","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/5SM3646-0LB 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}}