{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"3RH1921-1MA02","brand":"Siemens","brandSlug":"siemens","productSlug":"3RH1921-1MA02","canonicalUrl":"https://aoctrl.com/siemens/3RH1921-1MA02","factsUrl":"https://aoctrl.com/api/mcp/products/3RH1921-1MA02","rawCanonicalId":null},"summary":{"shortDescription":"Siemens SIRIUS auxiliary switch block, 2 NC contacts, screw-type terminals, snap-on mounting for 3RT1 contactors, 51 mm depth, 10 A max.","salesMarkdown":"It uses screw-type terminals and is rated for a maximum of 10 A, with specific current ratings that vary 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, among others. The block measures 51 mm deep, 44 mm wide, and 38 mm high, and carries an IP20 protection rating on the front. Snap-on mounting directly onto the 3RT1 contactor or contactor relay — no DIN rail needed, no extra hardware. The screw 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) and 2x (18 to 14) AWG. The block adds 51 mm of depth to the contactor assembly, so check enclosure clearance if retrofitting into a tight panel. ## Contact Ratings and Reliability The 2 NC contacts are rated for AC-15 duty at 690 V at 1 A. Mechanical service life is typical 10 million switching cycles.","metaTitle":"Siemens 3RH1921-1MA02 Auxiliary Switch Block, 2 NC, Screw Te","metaDescription":"Siemens SIRIUS 3RH1921-1MA02 auxiliary switch block, 2 NC contacts, screw terminals, snap-on for 3RT1 contactors. Phased-out; successor is 3RH2. Sourced to order.","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":"0","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=12897&mlfb=3RH1921-1MA02","alternativesUrl":"https://aoctrl.com/api/mcp/products/3RH1921-1MA02/alternatives.json"},"ai":{"faq":[{"question":"Where can I buy 3RH1921-1MA02 and get a price?","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 price and lead time."},{"question":"What does the note 'with 3RT1' mean for this part?","answer":"It means the 3RH1921-1MA02 auxiliary switch block is designed to mount directly onto Siemens 3RT1 series contactors and contactor relays."},{"question":"What is the depth of 3RH1921-1MA02?","answer":"The depth is 51 mm, which adds to the overall depth of the contactor assembly when mounted."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"matrix-langgraph","citationUrl":"https://aoctrl.com/siemens/3RH1921-1MA02","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/3RH1921-1MA02 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}}