{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"3RH1911-2FA20","brand":"Siemens","brandSlug":"siemens","productSlug":"3RH1911-2FA20","canonicalUrl":"https://aoctrl.com/siemens/3RH1911-2FA20","factsUrl":"https://aoctrl.com/api/mcp/products/3RH1911-2FA20","rawCanonicalId":null},"summary":{"shortDescription":"Siemens SIRIUS 3RH1911-2FA20 auxiliary switch block, 2 NO, spring-loaded terminals, snap-on mounting for size S00, 10 A max, IP20 front.","salesMarkdown":"It uses spring-loaded terminals for the auxiliary and control current circuit, accepting 2x (0.5... 1.5 mm²) with core-end processing or 2x (0.5... 2.5 mm²) without. The block is rated for a maximum current of 10 A, with switching capacity that varies significantly by voltage: 6 A at 24 V, 6 A at 125 V, 6 A at 230 V, 6 A at 250 V, 3 A at 400 V, and 0.3 A at 220 V. This voltage-dependent derating means the 10 A headline figure applies only at the lowest voltages; at 400 V the block is good for 3 A, and at 220 V for just 0.3 A — critical for control-circuit design where the load voltage may differ from the coil voltage. The block snaps onto a size S00 contactor or contactor relay, adding two NO auxiliary contacts without increasing the panel footprint beyond the contactor's own width of 36.5 mm and depth of 46 mm. The spring-loaded terminals accept AWG 20–14 conductors (2x) and require no screwdriver torque control, which speeds up wiring in high-density panels. ## Lifecycle Reality and Sourcing The 3RH1911-2FA20 is a phased-out product. The official Siemens successor is the SIRIUS 3RH2911-2HA20, which is the preferred replacement type. The mechanical service life is rated at 10,000,000 switching cycles typical, and contact reliability is specified as one incorrect switching operation per 100 million at 17 V, 5 mA, so the block is suitable for high-cycle applications where a direct replacement is needed. The insulation voltage is rated at 690 V with pollution degree 3, and surge voltage resistance is 6 kV — these figures define the block's suitability for 400 V and 690 V control circuits in industrial environments where overvoltage transients are common. The auxiliary contacts are also rated for AC-15 duty at 690 V at 1 A, which covers solenoid and contactor coil switching at higher voltages.","metaTitle":"Siemens 3RH1911-2FA20 Auxiliary Switch Block, 2 NO, Spring-T","metaDescription":"Siemens SIRIUS 3RH1911-2FA20 auxiliary switch block, 2 NO contacts, spring-loaded terminals, snap-on for size S00 contactors. Rated 10 A max, switching capacity varies by voltage.","metaKeywords":null},"attributes":{"series":null,"packageCase":null,"mountingType":null,"rohsStatus":null,"productStatus":null,"categoryPath":["Contactors"],"specifications":{"Note":"with 3RH1","Depth":"46 mm","Width":"36.5 mm","Height":"37.5 mm","Maximum":"10 A","at 24 V":"6 A","at 60 V":"2 A","at 110 V":"1 A","at 125 V":"6 A","at 220 V":"0.3 A","at 230 V":"6 A","at 250 V":"6 A","at 400 V":"3 A","Mounting type":"snap-on mounting","During Storage":"-55 ... +80 °C","lifecycle_stage":"current","During Operation":"-25 ... +60 °C","Product brand name":"SIRIUS","Contact reliability":"one incorrect switching operation of 100 million switching operations (17 V, 5 mA)","Suitability for use":"Contactor relay and power contactor","at 24 V rated value":"10 A","at 60 V rated value":"4.7 A","at 110 V rated value":"3 A","at 220 V rated value":"1.2 A","at 440 V rated value":"0.5 A","at 600 V rated value":"0.26 A","Instantaneous Contact":"2","With Core End Processing":"2x (0.5 ... 1.5 mm²)","Without Core End Processing":"2x (0.5 ... 2.5 mm²)","at AC-15 at 690 V rated value":"1 A","Protection class IP on the front":"IP20","Surge voltage resistance rated value":"6 kV","at AWG conductors for auxiliary contacts":"2x (20 ... 14)","Contact reliability of auxiliary contacts":"1 faulty switching per 100 million (17 V, 1 mA)","Mechanical service life (switching cycles) typical":"10 000 000","Insulation voltage with degree of pollution 3 rated value":"690 V","Type of electrical connection for auxiliary and control current circuit":"spring-loaded terminals"}},"commercial":{"minOrderQty":null,"leadTime":null,"referencePrice":"$43.21","priceTiers":null},"links":{"datasheetUrl":null,"sourceUrl":"https://support.industry.siemens.com/webbackend/api/ProductSupport/TechnicalData?language=en&region=cn&productId=121093&mlfb=3RH1911-2FA20","alternativesUrl":"https://aoctrl.com/api/mcp/products/3RH1911-2FA20/alternatives.json"},"ai":{"faq":[{"question":"What replaces the 3RH1911-2FA20?","answer":"The preferred successor is the Siemens SIRIUS 3RH2911-2HA20. This is the official replacement type for the phased-out 3RH1911-2FA20 auxiliary switch block."},{"question":"Will the 3RH1911-2FA20 fit a panel designed for the 3RT1015-1BB42 contactor?","answer":"The 3RH1911-2FA20 is an auxiliary switch block that snaps onto size S00 contactors. The 3RT1015-1BB42 is a size S00 power contactor, so the block is mechanically compatible for snap-on mounting. However, the 3RT1015-1BB42 uses screw-type terminals for its auxiliary contacts, while the 3RH1911-2FA20 uses spring-loaded terminals, so the wiring method differs. The block adds 2 NO contacts to the contactor's existing auxiliary configuration."},{"question":"What is the switching capacity of the 3RH1911-2FA20 at different voltages?","answer":"The maximum current is 10 A. At 24 V it switches 6 A; at 60 V, 4.7 A; at 110 V, 3 A; at 125 V, 6 A; at 220 V, 1.2 A; at 230 V, 6 A; at 250 V, 6 A; at 400 V, 3 A; at 440 V, 0.5 A; at 600 V, 0.26 A; and at 690 V AC-15, 1 A. The capacity drops significantly above 250 V, so verify the load voltage against the curve."},{"question":"What compliance documentation is available for the 3RH1911-2FA20?","answer":"The part carries an insulation voltage rating of 690 V with pollution degree 3 and surge voltage resistance of 6 kV, which aligns with IEC 60947-1 requirements. The IP20 front protection is standard for enclosed panels. For specific RoHS, REACH, or UL documentation, the Siemens SIRIUS series typically provides declarations on request through the supply channel."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"matrix-langgraph","citationUrl":"https://aoctrl.com/siemens/3RH1911-2FA20","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/3RH1911-2FA20 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}}