{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"3RH1921-1MA11","brand":"Siemens","brandSlug":"siemens","productSlug":"3RH1921-1MA11","canonicalUrl":"https://aoctrl.com/siemens/3RH1921-1MA11","factsUrl":"https://aoctrl.com/api/mcp/products/3RH1921-1MA11","rawCanonicalId":null},"summary":{"shortDescription":"Siemens SIRIUS auxiliary switch block, 1 NO + 1 NC, 2-pole screw terminal, snap-on mounting for 3RT1 contactors, 10 A max, 51 mm depth.","salesMarkdown":"It snaps onto the contactor's front side — no tools, no wiring changes to the main circuit. The screw-type terminals accept 2x (0.5 to 1.5 mm²) or 2x (0.75 to 2.5 mm²) conductors with core-end processing, or the AWG equivalents. ## Switching capacity across voltages Rated for AC-15 duty (solenoid and electromagnetic loads), the block carries 10 A at 24 V, 6 A at 125/230/250 V, 3 A at 400 V, and 0.26 A at 600 V. These are the switching currents at the respective control voltages — match your circuit's voltage to the row that governs the contactor coil or small solenoid you're piloting. ## Reliability and environmental limits Mechanical service life is 10 million switching cycles typical. Front-side protection is IP20, so the block belongs inside an enclosure, not exposed to washdown. Snap-on mounting onto the 3RT1 contactor body. Dimensions: 44 mm wide, 38 mm tall, 51 mm deep. The cable entry is at the bottom — plan your wire routing accordingly; the block does not accept top-entry wiring.","metaTitle":"Siemens 3RH1921-1MA11 SIRIUS Auxiliary Switch Block, 10 A","metaDescription":"Siemens SIRIUS 3RH1921-1MA11 auxiliary switch block, 1 NO + 1 NC, 10 A max, snap-on for 3RT1 contactors. Phased out; successor is 3RH2 series. 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":"1","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=313879&mlfb=3RH1921-1MA11","alternativesUrl":"https://aoctrl.com/api/mcp/products/3RH1921-1MA11/alternatives.json"},"ai":{"faq":[{"question":"What does the note 'with 3RT1' mean?","answer":"It means this auxiliary switch block is designed to mount directly onto Siemens 3RT1 series power contactors. It snaps onto the front of the contactor body and connects to the contactor's auxiliary contact interface."},{"question":"What are the key ratings for 3RH1921-1MA11?","answer":"Maximum thermal current is 10 A. AC-15 switching currents vary by voltage: 10 A at 24 V, 6 A at 125/230/250 V, 3 A at 400 V, 0.26 A at 600 V. Mechanical life is 10 million cycles. Operating temperature is -25 to +60 °C. Front IP20 rated."},{"question":"Will 3RH1921-1MA11 drop into a panel specified around 3RT1015-1BB42?","answer":"Yes — it is designed to mount on that exact contactor. The 3RT1015-1BB42 is a SIRIUS size S00 power contactor, and this auxiliary block snaps onto its front. No rewiring of the main circuit is needed; the block adds auxiliary contacts that wire separately to the screw terminals."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"matrix-langgraph","citationUrl":"https://aoctrl.com/siemens/3RH1921-1MA11","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/3RH1921-1MA11 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}}