{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"5SM1742-6","brand":"Siemens","brandSlug":"siemens","productSlug":"5SM1742-6","canonicalUrl":"https://aoctrl.com/siemens/5SM1742-6","factsUrl":"https://aoctrl.com/api/mcp/products/5SM1742-6","rawCanonicalId":null},"summary":{"shortDescription":"Siemens SENTRON 5SM1 series, 5SM1742-6 RCCB, 4-pole Type A, In 25 A, IΔn 500 mA, Un 400 V AC, instantaneous, DIN rail mount, IP20.","salesMarkdown":"The Siemens 5SM1742-6 is a 4-pole residual current circuit breaker (RCCB) from the SENTRON 5SM1 series, rated 25 A at 400 V AC with a 500 mA residual trip threshold — Type A sensitivity, so it catches pulsating DC fault currents as well as sinusoidal AC, which is what you need on circuits feeding single-phase rectified loads like switching power supplies or VFD auxiliaries. It snaps onto a DIN rail (4 width units, 55 mm installation depth), accepts top or bottom feed, and carries a 10 kA short-circuit current rating at 400 V — enough for most sub-distribution boards behind a larger upstream breaker. The 10 000 mechanical switching cycles typical service life means it will handle routine manual testing and infrequent fault clearing without wearing out early in a panel. At 40 °C ambient the 5SM1742-6 carries its full 25 A rating without derating. At 45 °C it still holds 25 A. Above that the current tapers: 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. The maximum permissible ambient is 60 °C; the minimum permissible is -40 °C. ## Installation notes Mounts in any position on DIN rail. The test circuit requires a minimum of 100 V to operate the test button. Silicon-free construction, size 1 per DIN 43880. Finger and back-of-hand safe touch protection on the terminals.","metaTitle":"Siemens 5SM1742-6 SENTRON RCCB, 25A 500mA 4P Type A, 400V","metaDescription":"Siemens 5SM1742-6 SENTRON RCCB, 4-pole Type A, 25A rated current, 500mA residual, 400V AC. IP20, DIN rail mount. Current lifecycle product. Quoted to order.","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":"500 mA","Size of installation devices / acc. to DIN 43880":"1","Mechanical service life (switching cycles) / typical":"10 000"}},"commercial":{"minOrderQty":null,"leadTime":null,"referencePrice":"$267.30","priceTiers":null},"links":{"datasheetUrl":null,"sourceUrl":"https://support.industry.siemens.com/webbackend/api/ProductSupport/TechnicalData?language=en&region=cn&productId=122550&mlfb=5SM1742-6","alternativesUrl":"https://aoctrl.com/api/mcp/products/5SM1742-6/alternatives.json"},"ai":{"faq":[{"question":"What is the 5SM1742-6's maximum ambient temperature rating?","answer":"The operating maximum is 45 °C; the maximum permissible (storage/transport) is 60 °C."},{"question":"What is the 5SM1742-6's minimum ambient temperature rating?","answer":"The operating minimum is -25 °C; the minimum permissible (storage/transport) is -40 °C."},{"question":"Where can I buy the 5SM1742-6 and how is it quoted?","answer":"The 5SM1742-6 is sourced and quoted to order against an RFQ through independent distribution. Availability and current pricing are confirmed at quote time."},{"question":"What compliance documentation does Siemens provide for the 5SM1742-6?","answer":"The product carries the SENTRON brand and is designed to IEC/EN 61008 standards for RCCBs. Specific RoHS, REACH, and UL documentation should be requested at quote time from the supplier."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"matrix-langgraph","citationUrl":"https://aoctrl.com/siemens/5SM1742-6","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/5SM1742-6 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}}