{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"5SM3446-0LA","brand":"Siemens","brandSlug":"siemens","productSlug":"5SM3446-0LA","canonicalUrl":"https://aoctrl.com/siemens/5SM3446-0LA","factsUrl":"https://aoctrl.com/api/mcp/products/5SM3446-0LA","rawCanonicalId":null},"summary":{"shortDescription":"Siemens SENTRON 5SM3 series, RCCB, 4-pole, type AC, In: 63 A, IΔn: 100 mA, Un: 400 V AC, 10 kA, DIN rail.","salesMarkdown":"The Siemens 5SM3446-0LA is a 4-pole residual current operated circuit breaker (RCCB) from the SENTRON 5SM3 series, designed for 400 V AC, 50 Hz systems. It's a type AC device — meaning it trips on sinusoidal AC residual currents — rated at 63 A load current with a 100 mA sensitivity. It includes thermal overload protection, so it doubles as an overload protector for the downstream circuit, not just a ground-fault interrupter. The 63 A rated current (In) sets the continuous load capacity — sized for a main feeder or a large sub-distribution board on a 400 V three-phase system. The 100 mA rated residual current (IΔn) is the trip threshold for earth leakage; at 100 mA it's above the 30 mA personal-protection level, so it's typically used for fire protection or equipment protection rather than direct shock protection. The 4-pole design (3 phases + neutral) with neutral switching means it disconnects all live conductors on a fault. Snaps onto DIN rail (REG profile) and occupies 4 width units (about 72 mm at 18 mm per unit). Installation depth is 70 mm, which fits standard distribution boards. Mounting position is any — no restriction on orientation. The terminals accept solid or stranded conductors from 1.5 to 25 mm², with a tightening torque of 2.5 to 3 N·m. Supply can come from top or bottom. ## What the approvals tell you The design complies with overvoltage category III per IEC/EN standards, which covers fixed-installation equipment. The silicon-free designation matters for applications where silicone outgassing can contaminate sensitive surfaces — e.g., in paint shops or electronics assembly areas. The finger and back-of-hand safe protection means the terminals are touch-safe when installed per the manufacturer's instructions.","metaTitle":"Siemens 5SM3446-0LA SENTRON RCCB, 63A 100mA 4P AC Type","metaDescription":"Siemens 5SM3446-0LA SENTRON RCCB, 4-pole, type AC, 63 A, 100 mA, 400 V AC, 10 kA SCCR, DIN rail mount. Active production. Available to order.","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","Mounting type":"DIN rail (REG)","During Storage":"-40 ... +75 °C","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":"-5 ... +45 °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":"Instantaneous","Number of width units":"4","Type of fault current":"AC","circuit-breaker / Design":"5SM3","Short-circuit current rating":"10 kA","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","Switching function / short-term delayed":"No","Tripping residual current / rated value":"100 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=263686&mlfb=5SM3446-0LA","alternativesUrl":"https://aoctrl.com/api/mcp/products/5SM3446-0LA/alternatives.json"},"ai":{"faq":[{"question":"Where can I buy 5SM3446-0LA and get a price?","answer":"This part is sourced and quoted to order against an RFQ through independent distribution channels. Availability and current pricing are confirmed at quote time — submit an RFQ for a firm commercial offer."},{"question":"What is the closest functional second-source to 5SM3446-0LA?","answer":"The closest functional peer in the SENTRON family is the 5SY4310-7CV, but it's a different class of device — a 3-pole MCB (miniature circuit breaker) with a 10 A rating and C-curve trip characteristic, not an RCCB. It does not provide residual current protection or thermal overload protection in the same way. For a direct functional replacement, you'd need another 4-pole type AC RCCB with matching 63 A / 100 mA ratings; the 5SM3446-0LA is the correct specification."},{"question":"Will 5SM3446-0LA drop into a panel specified around 5SY4310-7CV?","answer":"No — the 5SY4310-7CV is a 3-pole MCB occupying 3 width units, while the 5SM3446-0LA is a 4-pole RCCB occupying 4 width units. The DIN rail mounting is the same, but the width, number of poles, function, and wiring are different. You cannot swap them without panel modification and circuit redesign."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"matrix-langgraph","citationUrl":"https://aoctrl.com/siemens/5SM3446-0LA","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/5SM3446-0LA 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}}