{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"3RH1921-1FE11","brand":"Siemens","brandSlug":"siemens","productSlug":"3RH1921-1FE11","canonicalUrl":"https://aoctrl.com/siemens/3RH1921-1FE11","factsUrl":"https://aoctrl.com/api/mcp/products/3RH1921-1FE11","rawCanonicalId":null},"summary":{"shortDescription":"Siemens SIRIUS auxiliary switch, solid-state-compatible, for 3RT1 contactor relay size S0, 1 NO contact, 0.3 A at 24 V / 60 V, screw terminals, snap-on mounting, IP20 front, 51 x 44 x 38 mm.","salesMarkdown":"The Siemens SIRIUS 3RH1921-1FE11 is a solid-state-compatible auxiliary switch block designed to snap onto a 3RT1 contactor relay in size S0. It carries a single instantaneous NO contact rated at 0.3 A at both 24 V and 60 V — a low-energy signal rating, not a power-switching contact. The screw-type terminals accept 2x (0.5 to 1.5 mm²) or 2x (0.75 to 2.5 mm²) with core-end processing, or 2x (20 to 16) / 2x (18 to 14) AWG. ## Lifecycle reality — phased out, successor identified This part is a phased-out product. The official Siemens successor is the SIRIUS 3RH2 series. If you are maintaining a panel built around the 3RT1 / 3RH1921 platform, the 3RH2 is the drop-in replacement path for new builds or when spares run dry. The 0.3 A contact rating at 24 V and 60 V tells you this switch is intended for PLC or electronic control inputs, not for pilot-duty solenoids or contactor coils directly. The mechanical life of 5 million switching cycles is typical for a block mounted on a contactor relay that itself cycles at lower frequencies. That puts it in the standard 400 VAC panel class for industrial control circuits. Snap-on mounting onto the 3RT1 contactor relay in size S0. No DIN rail footprint of its own — it clips directly to the relay, adding 51 mm depth, 44 mm width, and 38 mm height to the assembly.","metaTitle":"Siemens 3RH1921-1FE11 SIRIUS Auxiliary Switch, 0.3 A, phased","metaDescription":"Siemens SIRIUS 3RH1921-1FE11 auxiliary switch for 3RT1 contactor relay size S0. 0.3 A at 24/60 V, IP20 front, snap-on. Phased out; successor is 3RH2. Sourced to order against RFQ.","metaKeywords":null},"attributes":{"series":null,"packageCase":null,"mountingType":null,"rohsStatus":null,"productStatus":null,"categoryPath":["Contactors"],"specifications":{"Note":"with 3RT1","Depth":"51 mm","Width":"44 mm","Height":"38 mm","at 24 V":"0.3 A","at 60 V":"0.3 A","During Storage":"-55 ... +80 °C","lifecycle_stage":"current","During Operation":"-25 ... +60 °C","Fastening Method":"snap-on mounting","Product Brand Name":"SIRIUS","Suitability For Use":"Contactor relay and power contactor","Instantaneous Contact":"1","With Core End Processing":"2x (0.5 ... 1.5 mm²), 2x (0.75 ... 2.5 mm²)","protection class IP on the front":"IP20","Surge Voltage Resistance Rated Value":"6 kV","at AWG cables for auxiliary contacts":"2x (20 ... 16), 2x (18 ... 14)","Contact Reliability Of Auxiliary Contacts":"1 faulty switching per 100 million (17 V, 1 mA)","Mechanical Service Life (Switching Cycles) Typical":"5 000 000","Type Of Electrical Connection For Auxiliary And Control Circuit":"screw-type terminals","insulation voltage with degree of pollution 3 at AC rated value":"690 V"}},"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=459391&mlfb=3RH1921-1FE11","alternativesUrl":"https://aoctrl.com/api/mcp/products/3RH1921-1FE11/alternatives.json"},"ai":{"faq":[{"question":"Where can I buy 3RH1921-1FE11?","answer":"This part is sourced to order against an RFQ through independent distribution channels. Availability and current pricing are confirmed at quote time."},{"question":"What does the note 'with 3RT1' mean?","answer":"It means this auxiliary switch block is designed to attach directly onto a Siemens 3RT1 contactor relay in size S0. It is not a standalone device — it clips onto the relay."},{"question":"What is the contact rating of 3RH1921-1FE11?","answer":"The single NO contact is rated at 0.3 A at both 24 V and 60 V. This is a low-energy signal rating for PLC or electronic inputs, not for switching power loads."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"matrix-langgraph","citationUrl":"https://aoctrl.com/siemens/3RH1921-1FE11","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/3RH1921-1FE11 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}}