{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"3RH1921-1FA22-ZW97","brand":"Siemens","brandSlug":"siemens","productSlug":"3RH1921-1FA22-ZW97","canonicalUrl":"https://aoctrl.com/siemens/3RH1921-1FA22-ZW97","factsUrl":"https://aoctrl.com/api/mcp/products/3RH1921-1FA22-ZW97","rawCanonicalId":null},"summary":{"shortDescription":"Siemens SIRIUS auxiliary switch block, 4-pole 2NO+2NC, EN 50005, screw terminals, 10A rated, snap-on mounting for 3RT1 contactors.","salesMarkdown":"The Siemens 3RH1921-1FA22-ZW97 is a SIRIUS auxiliary switch block — a 4-pole block with 2 normally-open and 2 normally-closed contacts, designed to snap onto 3RT1 contactors and contactor relays. It carries a 10 A maximum rating and switches auxiliary circuits across a wide voltage range: 6 A at 24 V, 6 A at 125 V, 6 A at 230 V, and 3 A at 400 V, among other ratings. The block uses screw-type terminals and accepts 2x (0.5 to 1.5 mm²) or 2x (0.75 to 2.5 mm²) wire with core end processing, or 2x (20 to 16) or 2x (18 to 14) AWG. Front protection is IP20, insulation voltage is 690 V at pollution degree 3, and surge voltage resistance is 6 kV. Mechanical life is 10 million switching cycles typical. The 10 A maximum is the thermal current (Ith) through the contacts, but the real-world switching capacity depends on voltage and load type. For a 24 V DC control circuit, the contacts handle 6 A — that's the figure to use when sizing for a PLC output or relay coil. At 110 V, derate to 1 A; at 220 V, 0.3 A. The AC-15 rating at 690 V is 1 A, which covers inductive loads like contactor coils at higher line voltages. The 2 NO + 2 NC configuration (EN 50005 layout) gives flexibility for interlocking, status feedback, or auxiliary circuits without an extra block. The snap-on mounting means it clips directly onto the 3RT1 contactor or contactor relay — no tools needed for installation, but verify the contactor frame size (S00/S0/S2/S3) matches the block's intended fit.","metaTitle":"Siemens 3RH1921-1FA22-ZW97 SIRIUS Auxiliary Switch Block, 2N","metaDescription":"Siemens 3RH1921-1FA22-ZW97 SIRIUS auxiliary switch block, 4-pole 2NO+2NC, rated 10A, snap-on mounting. Phased-out; successor is 3RH2 series. Quoted 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","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","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","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), 2x (0.75 ... 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 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":"10 000 000","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=506061&mlfb=3RH1921-1FA22-ZW97","alternativesUrl":"https://aoctrl.com/api/mcp/products/3RH1921-1FA22-ZW97/alternatives.json"},"ai":{"faq":[{"question":"What replaces 3RH1921-1FA22-ZW97?","answer":"The official successor is the SIRIUS 3RH2 series. The 3RH2122-1WB40 is a close functional peer — same 2 NO + 2 NC configuration, same 10 A rated current at 24 V, same screw-type terminals, and same 6 kV surge voltage resistance. The 3RH2 series uses screw and snap-on mounting onto 35 mm DIN rail, so it will not drop into the same footprint as the 3RH1921 without verifying the contactor interface."},{"question":"Where can I buy 3RH1921-1FA22-ZW97?","answer":"This part is sourced and quoted to order against an RFQ through independent distribution. Availability and current pricing are confirmed at quote time — submit an RFQ for a firm commitment."},{"question":"What is the note 'with 3RT1' on this component?","answer":"The note indicates this auxiliary switch block is designed to mount onto 3RT1 contactors and contactor relays. It snaps onto the contactor without additional hardware."},{"question":"What are the key ratings for 3RH1921-1FA22-ZW97?","answer":"Maximum rated current is 10 A. Switching capacity varies by voltage: 6 A at 24 V, 6 A at 125 V, 6 A at 230 V, 3 A at 400 V, 1 A at 110 V, 0.3 A at 220 V. AC-15 rating at 690 V is 1 A. Insulation voltage is 690 V at pollution degree 3, surge voltage resistance is 6 kV. Mechanical life is 10 million switching cycles typical. Contact reliability is 1 faulty switching per 100 million at 17 V, 1 mA."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"matrix-langgraph","citationUrl":"https://aoctrl.com/siemens/3RH1921-1FA22-ZW97","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/3RH1921-1FA22-ZW97 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}}