{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"5SM1644-6","brand":"Siemens","brandSlug":"siemens","productSlug":"5SM1644-6","canonicalUrl":"https://aoctrl.com/siemens/5SM1644-6","factsUrl":"https://aoctrl.com/api/mcp/products/5SM1644-6","rawCanonicalId":null},"summary":{"shortDescription":"Siemens SENTRON RCCB, 4-pole, Type A, 40 A at 40 °C, 300 mA trip, 400 V AC, 50 Hz, DIN rail mount, IP20.","salesMarkdown":"The Siemens 5SM1644-6 is a 4-pole residual current circuit breaker (RCCB) from the SENTRON series, rated 40 A at 40 °C and 400 V AC at 50 Hz. It trips on Type A fault currents at 300 mA, covering pulsating DC and sinusoidal AC residual currents — the standard choice for circuits with single-phase rectifiers, switched-mode supplies, or electronic loads that generate smooth DC fault components. Rated current holds at 40 A up to 45 °C ambient. Above that, derate linearly: 38.4 A at 50 °C, 36.8 A at 55 °C, 35.2 A at 60 °C, 33.6 A at 65 °C, and 32 A at 70 °C (–). The 4.8 W maximum power loss is manageable in a standard enclosure but should be factored into thermal calculations for densely populated DIN-rail assemblies. ## Fault current ratings and selectivity Short-circuit current rating is 10 kA. Per EN 60898 the rated breaking capacity is 0.8 kA; per IEC 61008-1 it is also 0.8 kA. Surge current resistance is 1 kA. The 300 mA trip threshold suits circuits where a 30 mA device would nuisance-trip due to cumulative leakage from multiple loads — common on distribution sub-mains, EV chargers, or industrial socket circuits with long cable runs. ## Mechanical and installation data Mounts on DIN rail (REG) in any position. Occupies 4 width units, size 1 per DIN 43880. Installation depth is 55 mm. Protection class IP20 with distribution board installed and conductors connected. Finger and back-of-hand safe. Silicon-free construction.","metaTitle":"Siemens 5SM1644-6 SENTRON RCCB, 4P, 40 A, 300 mA, Type A","metaDescription":"Siemens 5SM1644-6 SENTRON 4-pole RCCB, 40 A rated, 300 mA Type A, 10 kA SCCR, 400 V AC, 50 Hz. DIN rail mount, IP20. 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":"-25 °C","Rated Value":"50 Hz","Mounting type":"DIN rail (REG)","Number Of Poles":"4","lifecycle_stage":"current","Mounting Position":"any","Installation Depth":"55 mm","Product Brand Name":"SENTRON","Maximum Permissible":"60 °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":"A","at 40 °C / rated value":"40 A","at 45 °C / rated value":"40 A","at 50 °C / rated value":"38.4 A","at 55 °C / rated value":"36.8 A","at 60 °C / rated value":"35.2 A","at 65 °C / rated value":"33.6 A","at 70 °C / rated value":"32 A","power loss [W] / maximum":"4.8 W","Short-circuit current rating":"10 kA","Product Feature / Silicon-Free":"Yes","acc. to EN 60898 / rated value":"0.8 kA","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","according to IEC 61008-1 / rated value":"0.8 kA","Operating current / at AC / rated value":"40 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=505230&mlfb=5SM1644-6","alternativesUrl":"https://aoctrl.com/api/mcp/products/5SM1644-6/alternatives.json"},"ai":{"faq":[{"question":"How do I get current pricing and availability for 5SM1644-6?","answer":"Submit an RFQ through this listing. The part is sourced to order through independent distribution; pricing and stock levels are confirmed at quote time."},{"question":"What is 5SM1644-6's listed maximum ambient temperature?","answer":"The maximum operating ambient temperature is 45 °C. The rated current of 40 A holds at that temperature; above 45 °C derating applies as listed in the spec table."},{"question":"What is 5SM1644-6's listed minimum ambient temperature?","answer":"The minimum operating ambient temperature is -25 °C. Storage minimum is -40 °C."},{"question":"What compliance documentation does this brand provide for 5SM1644-6?","answer":"The product is designed to EN 60898 and IEC 61008-1. It carries a silicon-free declaration. For specific RoHS, REACH, or UL documentation, request the manufacturer's declaration of compliance with the RFQ."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"matrix-langgraph","citationUrl":"https://aoctrl.com/siemens/5SM1644-6","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/5SM1644-6 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}}