{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"5SM3646-6KL","brand":"Siemens","brandSlug":"siemens","productSlug":"5SM3646-6KL","canonicalUrl":"https://aoctrl.com/siemens/5SM3646-6KL","factsUrl":"https://aoctrl.com/api/mcp/products/5SM3646-6KL","rawCanonicalId":null},"summary":{"shortDescription":"Siemens SENTRON 5SM3646-6KL, 4-pole RCCB, type AC, 63 A rated current, 300 mA residual, 400 V AC, instantaneous, N left, DIN rail mount.","salesMarkdown":"The Siemens SENTRON 5SM3646-6KL is a 4-pole residual current circuit breaker (RCCB) rated for 63 A at 400 V AC, with a 300 mA type AC tripping characteristic. It's an instantaneous device — no intentional delay — so it trips as soon as the residual current exceeds the threshold. That makes it a fit for general-purpose earth-leakage protection where nuisance tripping from transient surges isn't a concern. Snaps onto DIN rail (REG) and occupies 4 width units at 72 mm wide. The neutral is wired on the left side (N left variant). Mounting position is any, so vertical or horizontal busbar arrangements work. IP20 protection applies once the distribution board is installed and conductors are connected; the device itself isn't rated for wet environments. ## What the ratings mean The 300 mA residual threshold is higher than the 30 mA used for personal shock protection — it's typically specified for fire prevention or equipment protection where some leakage is expected. Type AC means it detects sinusoidal AC residual currents only; pulsating DC or smooth DC faults won't trip it, so don't use it downstream of variable-speed drives or UPS systems without verifying the fault-current profile. Surge current resistance is rated at 1 kA, which means it can withstand the inrush from a nearby lightning strike or switching surge without welding the contacts or false-tripping. Mechanical life is 10,000 switching cycles typical — adequate for a protective device that operates infrequently, not a switching contactor. ## Ambient limits and approvals Overvoltage category III, so it's suitable for fixed installation downstream of the utility meter. Finger and back-of-hand safe per the shock-protection design. Silicon-free construction — relevant for potting or conformal-coating processes in sensitive electronics environments.","metaTitle":"Siemens 5SM3646-6KL SENTRON RCCB, 63 A, 300 mA, 4-Pole, Type","metaDescription":"Siemens SENTRON 5SM3646-6KL 4-pole RCCB, 63 A rated current, 300 mA residual, type AC, 400 V, instantaneous. 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","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","Product variations":"N left","Maximum Permissible":"75 °C","Minimum Permissible":"-40 °C","Operating frequency":"50 Hz","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","acc. to DIN EN 61346-2":"F","acc. to DIN EN 81346-2":"F","circuit-breaker / Design":"5SM3","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","Operating current / at AC / rated value":"63 A","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=221063&mlfb=5SM3646-6KL","alternativesUrl":"https://aoctrl.com/api/mcp/products/5SM3646-6KL/alternatives.json"},"ai":{"faq":[{"question":"Where can I buy 5SM3646-6KL and how is it quoted?","answer":"This part is sourced and quoted to order against an RFQ through independent distribution. Availability and current pricing are confirmed at quote time — submit an RFQ for a firm commercial offer."},{"question":"What is the depth of 5SM3646-6KL?","answer":"The overall depth is 77 mm, with an installation depth of 70 mm. Verify your enclosure depth allows clearance for wiring and busbar connections."},{"question":"Will 5SM3646-6KL fit a panel designed for a 5SY4304-7CV?","answer":"Not without modification. The 5SM3646-6KL is 72 mm wide (4 width units), while the 5SY4304-7CV is 54 mm wide (3 width units). The 5SM also requires neutral wiring on the left side. The panel would need a wider DIN-rail slot and possibly busbar reconfiguration."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"matrix-langgraph","citationUrl":"https://aoctrl.com/siemens/5SM3646-6KL","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/5SM3646-6KL 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}}