{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"3RH1921-1CA10-ZW98","brand":"Siemens","brandSlug":"siemens","productSlug":"3RH1921-1CA10-ZW98","canonicalUrl":"https://aoctrl.com/siemens/3RH1921-1CA10-ZW98","factsUrl":"https://aoctrl.com/api/mcp/products/3RH1921-1CA10-ZW98","rawCanonicalId":null},"summary":{"shortDescription":"Siemens SIRIUS 3RH1921-1CA10-ZW98 auxiliary switch, 1 N/O, snap-on front mount for S0 contactors, 10 A AC-12, 6 kV surge, IP20.","salesMarkdown":"The 3RH1921-1CA10-ZW98 is a SIRIUS auxiliary switch designed to snap onto the front of S0-size contactors and contactor relays. It adds one N/O mirror contact that tracks the main contactor's position, which matters when you need to prove the main poles have opened — the mirror contact per IEC 60947-4-1 is mechanically linked so it cannot indicate closed when the main contacts are welded. Rated 10 A at AC-12 (resistive loads) and 6 A at 230 V, but the real selection number is the AC-15 rating at the control voltage you're switching. At 24 V it handles 6 A; at 110 V it's 1 A; at 400 V it's 3 A. The AC-15 duty covers solenoid and contactor coils — the typical load on an auxiliary contact in a motor starter panel. If you're switching a 24 VDC PLC output signal, note the DC ratings: 10 A at 24 V, dropping to 0.5 A at 440 V. The 6 kV surge voltage resistance means it holds the unit on the grid through switching transients without flashover across the open contact gap. Snaps onto the front of the S0 contactor — no tools, no DIN rail space consumed beyond the contactor's own footprint. The auxiliary switch itself is 10 mm wide, 51 mm deep, 38 mm high. That 10 mm width is the key dimension for panel fill: if you're stacking multiple auxiliaries on a single contactor, each one adds 10 mm to the overhang. Wire termination accepts two conductors per terminal: 2x (0.5 to 1.5 mm²) solid or finely stranded with ferrules, or 2x (0.75 to 2.5 mm²). For AWG, that's 2x (20 to 16) and 2x (18 to 14).","metaTitle":"Siemens 3RH1921-1CA10-ZW98 SIRIUS Auxiliary Switch, S0, 10A","metaDescription":"Siemens 3RH1921-1CA10-ZW98 SIRIUS auxiliary switch for S0 contactors. Snap-on front mount, 1 N/O contact, 10A AC-12, IP20. Current production, sourced to order.","metaKeywords":null},"attributes":{"series":null,"packageCase":null,"mountingType":null,"rohsStatus":null,"productStatus":null,"categoryPath":["Contactors"],"specifications":{"Depth":"51 mm","Width":"10 mm","Height":"38 mm","at 24 V":"6 A","at 48 V":"2 A","at 60 V":"2 A","at 110 V":"1 A","at 125 V":"0.9 A","at 220 V":"0.3 A","at 230 V":"6 A","at 250 V":"0.3 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 Category":"Auxiliary switch","Size Of Contactor":"S0","Solid Or Stranded":"2x (0.5 ... 1.5 mm²), 2x (0.75 ... 2.5 mm²)","Product Brand Name":"SIRIUS","Product Designation":"auxiliary switch","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","Design Of The Product":"for snapping onto the front","Instantaneous Contact":"1","Substance Prohibitance (Date)":"07/01/2006","protection class IP on the front":"IP20","Surge Voltage Resistance Rated Value":"6 kV","for AWG cables for auxiliary contacts":"2x (20 ... 16), 2x (18 ... 14)","Finely Stranded With Core End Processing":"2x (0.5 ... 1.5 mm²), 2x (0.75 ... 2.5 mm²)","Contact Reliability Of Auxiliary Contacts":"1 faulty switching per 100 million (17 V, 1 mA)","mirror contact according to IEC 60947-4-1":"Yes; with 3RT1","operational current at AC-15 at 690 V rated value":"1 A","Mechanical Service Life (Operating Cycles) Typical":"10 000 000","operational current of auxiliary contacts at AC-12 maximum":"10 A","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","number of CO contacts of auxiliary contacts instantaneous contact":"0","AWG number as coded connectable conductor cross section for auxiliary contacts":"20 ... 14"}},"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=264517&mlfb=3RH1921-1CA10-ZW98","alternativesUrl":"https://aoctrl.com/api/mcp/products/3RH1921-1CA10-ZW98/alternatives.json"},"ai":{"faq":[{"question":"Will the 3RH1921-1CA10-ZW98 drop into a panel specified around the 3RT2027-1AF00 without rewiring?","answer":"The 3RH1921-1CA10-ZW98 is designed to snap onto the front of S0-size contactors. The 3RT2027-1AF00 is a S0 contactor, so this auxiliary switch mounts directly to it. The wiring terminals accept the same conductor sizes, so if the panel was laid out for a S0 contactor with a front-mounted auxiliary, this part fits without panel rework."},{"question":"What are the key switching ratings for this auxiliary switch?","answer":"AC-12 maximum 10 A. AC-15 at 24 V is 6 A, at 110 V is 1 A, at 400 V is 3 A, and at 690 V is 1 A. DC ratings: 10 A at 24 V, 4.7 A at 60 V, 3 A at 110 V, 1.2 A at 220 V, 0.5 A at 440 V, and 0.26 A at 600 V."},{"question":"What compliance documentation is available for this part?","answer":"The part carries a substance prohibition date of July 1, 2006, indicating RoHS compliance. It is a Siemens SIRIUS catalog item, so standard CE, UL, and CSA certifications apply to the SIRIUS contactor/auxiliary switch family, though specific cert marks are not listed in the available spec data for this exact order code."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"matrix-langgraph","citationUrl":"https://aoctrl.com/siemens/3RH1921-1CA10-ZW98","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/3RH1921-1CA10-ZW98 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}}