{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"3RH1921-1HA31","brand":"Siemens","brandSlug":"siemens","productSlug":"3RH1921-1HA31","canonicalUrl":"https://aoctrl.com/siemens/3RH1921-1HA31","factsUrl":"https://aoctrl.com/api/mcp/products/3RH1921-1HA31","rawCanonicalId":null},"summary":{"shortDescription":"Siemens SIRIUS auxiliary switch block, 3RH1921-1HA31, 3 NO + 1 NC, screw-type terminals, snap-on mounting for 3RT1 contactors, 10 A maximum, 51 mm depth.","salesMarkdown":"The Siemens SIRIUS 3RH1921-1HA31 is a 4-pole auxiliary switch block with a 3 NO + 1 NC contact configuration, wired via screw-type terminals and designed to snap onto 3RT1 contactors in the S0 through S12 frame sizes. It carries a maximum thermal current of 10 A, with a rated operational current of 10 A at 24 V (AC-15/DC-13) and 6 A at 230 V. The block measures 51 mm deep, 44 mm wide, and 38 mm high, and is rated for 10 million mechanical operating cycles typical. Front-side IP20 protection covers the terminals. Mounting is snap-on onto the contactor — no DIN rail required for the block itself; it clips directly to the 3RT1 contactor. The screw terminals accept two conductors per clamp: 2x (0.5 to 1.5 mm²) or 2x (0.75 to 2.5 mm²) with ferrule, or 2x (20 to 16) and 2x (18 to 14) AWG. Surge voltage resistance is rated at 6 kV, and the insulation voltage at pollution degree 3 is 690 V AC.","metaTitle":"Siemens 3RH1921-1HA31 Auxiliary Switch Block, 3 NO+1 NC, Scr","metaDescription":"Siemens SIRIUS 3RH1921-1HA31 auxiliary switch block, 3 NO + 1 NC, 10 A max, snap-on for 3RT1 contactors. Phased-out; successor is 3RH2. Available 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":"3","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 (Operating 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=119780&mlfb=3RH1921-1HA31","alternativesUrl":"https://aoctrl.com/api/mcp/products/3RH1921-1HA31/alternatives.json"},"ai":{"faq":[{"question":"What is the closest functional second-source for 3RH1921-1HA31?","answer":"The closest functional second-source is the SIRIUS 3RH2 series, which is the official successor. The 3RH2140-1BP40 is a 4-pole auxiliary contactor with similar ratings (10 A at 24 V, 6 kV surge) but mounts on a DIN rail and has a different footprint (73 mm depth vs. 51 mm). It will not drop into a panel wired for the 3RH1921-1HA31 without rewiring the mounting."},{"question":"Where can I buy 3RH1921-1HA31?","answer":"This part is sourced to order against an RFQ through independent distribution. Availability and current pricing are confirmed at quote time."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"matrix-langgraph","citationUrl":"https://aoctrl.com/siemens/3RH1921-1HA31","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/3RH1921-1HA31 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}}