{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"5SM1642-6","brand":"Siemens","brandSlug":"siemens","productSlug":"5SM1642-6","canonicalUrl":"https://aoctrl.com/siemens/5SM1642-6","factsUrl":"https://aoctrl.com/api/mcp/products/5SM1642-6","rawCanonicalId":null},"summary":{"shortDescription":"Siemens SENTRON 5SM1 series RCCB, 4-pole, Type A, 25 A rated, 300 mA trip, 400 V AC, instantaneous, DIN rail mount.","salesMarkdown":"The Siemens 5SM1642-6 is a 4-pole residual current circuit breaker (RCCB) from the SENTRON 5SM1 series, rated at 25 A and 300 mA sensitivity, 400 V AC, Type A, instantaneous trip. It mounts on DIN rail (REG) and occupies 4 width units (roughly 72 mm on the rail). The Type A designation means it detects sinusoidal AC fault currents plus pulsating DC fault currents — common in modern equipment with rectified loads like VFDs, switching power supplies, and LED drivers. The 300 mA trip threshold is a standard for general protection in industrial and commercial distribution boards where nuisance tripping from leakage currents must be avoided. ## De-rating and ambient limits The 5SM1642-6 carries its full 25 A rating at 40 °C and 45 °C ambient. Above that, it de-rates linearly: 24 A at 50 °C, 23 A at 55 °C, 22 A at 60 °C, 21 A at 65 °C, and 20 A at 70 °C. In a crowded enclosure with multiple devices shedding heat, check the internal ambient — if it pushes past 45 °C, the available current drops. The part is finger and back-of-hand safe (IP20 with distribution board installed and conductors connected). ## Fault current and coordination This is an instantaneous RCCB (no short-time delay), so it trips within milliseconds of a fault exceeding 300 mA. The permissible I²t value is 70 000 A²·s, which governs the let-through energy the device can handle during a fault. Surge current resistance is rated at 1 kA (8/20 µs waveform typical). For selectivity with upstream devices, note the instantaneous characteristic — it will trip on any fault above threshold, so coordinate with the upstream MCB or fuse to avoid nuisance blackouts on a branch fault. ## Installation notes Mounts on standard DIN rail (DIN 43880 size 1). Installation depth is 55 mm. Mounting position is any. The device is silicon-free, which matters for certain potting or conformal-coating environments. The test circuit requires a minimum of 100 V to operate the test button. No auxiliary contacts or shunt trip are integrated; if you need remote tripping or status feedback, you'll need an external accessory.","metaTitle":"Siemens 5SM1642-6 SENTRON RCCB, 25A 300mA 4P Type A","metaDescription":"Siemens 5SM1642-6 SENTRON RCCB, 4-pole, Type A, 25 A, 300 mA, 400 V AC. Current production. 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","at 40 Cel":"25 A","at 45 Cel":"25 A","at 50 Cel":"24 A","at 55 Cel":"23 A","at 60 Cel":"22 A","at 65 Cel":"21 A","at 70 Cel":"20 A","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","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","I2t-value / permissible":"70 000 A²·s","circuit-breaker / Design":"5SM1","Short-circuit current rating":"10 kA","Current / at AC / rated value":"25 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=29827&mlfb=5SM1642-6","alternativesUrl":"https://aoctrl.com/api/mcp/products/5SM1642-6/alternatives.json"},"ai":{"faq":[{"question":"What is the 5SM1642-6 used for?","answer":"It is a 4-pole Type A RCCB used for residual current protection in industrial and commercial distribution boards, rated 25 A, 300 mA, 400 V AC. Type A covers sinusoidal AC and pulsating DC fault currents."},{"question":"What is the maximum ambient temperature for the 5SM1642-6?","answer":"The maximum operating ambient temperature is 60 °C, with de-rating starting above 45 °C. Full 25 A rating holds up to 45 °C."},{"question":"What is the minimum ambient temperature for the 5SM1642-6?","answer":"The minimum operating ambient temperature is -25 °C. Storage minimum is -40 °C."},{"question":"Where can I buy the 5SM1642-6?","answer":"The 5SM1642-6 is available to order through independent distribution. Submit an RFQ for current availability and pricing; it is quoted to order."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"matrix-langgraph","citationUrl":"https://aoctrl.com/siemens/5SM1642-6","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/5SM1642-6 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}}