{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"3RH2122-2KF40","brand":"Siemens","brandSlug":"siemens","productSlug":"3RH2122-2KF40","canonicalUrl":"https://aoctrl.com/siemens/3RH2122-2KF40","factsUrl":"https://aoctrl.com/api/mcp/products/3RH2122-2KF40","rawCanonicalId":null},"summary":{"shortDescription":"Siemens SIRIUS S00 coupling relay, 3RH2122-2KF40, for switching auxiliary circuits, 110 V DC coil, 2 NO contacts, screw and snap-on mounting on 35 mm DIN rail.","salesMarkdown":"The Siemens SIRIUS 3RH2122-2KF40 is an S00-size coupling relay designed for switching auxiliary circuits in control panels. It carries two instantaneous normally-open contacts and a 110 V DC coil with an integrated suppressor diode, so no external flyback diode is needed across the coil terminals. Rated switching current varies by voltage: 10 A at 24 V and 230 V, 3 A at 110 V and 400 V, 1.2 A at 220 V, and derated further at higher voltages down to 0.26 A at 600 V. The AC-15 / DC-13 duty class governs these numbers — use the 230 V 10 A figure for typical pilot-duty lamp or contactor coil loads, and the 24 V 10 A for DC solenoid valves in the same panel. The S00 footprint (73 mm deep, 45 mm wide, 70 mm tall) matches the standard SIRIUS contactor grid, so it shares the same rail pitch as the 3RT2 contactor line. Clearance of 10 mm upwards and forwards, 6 mm at the side keeps heat rise manageable in a dense cabinet. ## Integration Notes The built-in suppressor diode clamps the DC coil flyback; no external snubber required.","metaTitle":"Siemens 3RH2122-2KF40 SIRIUS Coupling Relay, 110 V DC, 2 NO","metaDescription":"Siemens SIRIUS 3RH2122-2KF40 S00 coupling relay for auxiliary circuits. Rated 110 V DC coil, 2 instantaneous NO contacts, screw/snap-on DIN rail. Current lifecycle stage. Sourced t","metaKeywords":null},"attributes":{"series":null,"packageCase":null,"mountingType":null,"rohsStatus":null,"productStatus":"Active","categoryPath":["Contactors"],"specifications":{"Depth":"73 mm","Width":"45 mm","at AC":"10 000 1/h","at DC":"7 ... 20 ms","title":"3RH2122-2KF40","Height":"70 mm","Upwards":"10 mm","Forwards":"10 mm","Downwards":"10 mm","Arcing Time":"10 ... 15 ms","At The Side":"6 mm","Rated Value":"110 V","description":"Coupling contactor relay, 2 NO + 2 NC, 110 V DC, 0.7... 1.25* US, with integrated suppressor diode, Size S00, Spring-type terminal suitable for PLC outputs","Initial Value":"0.7","During Storage":"-55 ... +80 °C","lifecycle_stage":"current","During Operation":"-25 ... +60 °C","Fastening Method":"screw and snap-on mounting onto 35 mm DIN rail","Full-Scale Value":"1.25","Mounting Position":"+/-180° rotation possible on vertical mounting surface; can be tilted forward and backward by +/- 22.5° on vertical mounting surface","Size Of Contactor":"S00","Solid Or Stranded":"2x (0,5 ... 4 mm²)","Product Brand Name":"SIRIUS","Degree Of Pollution":"3","Product Designation":"Coupling relay for switching auxiliary circuits","at 24 V rated value":"10 A","at 60 V rated value":"4.7 A","Of Contactor Typical":"30 000 000","at 110 V rated value":"3 A","at 220 V rated value":"1.2 A","at 230 V rated value":"10 A","at 400 V rated value":"3 A","at 440 V rated value":"0.5 A","at 500 V rated value":"2 A","at 600 V rated value":"0.26 A","at 690 V rated value":"1 A","Instantaneous Contact":"2","Relative Humidity Minimum":"10 %","Substance Prohibitance (Date)":"10/01/2009","Design Of The Surge Suppressor":"suppressor diode","Product Extension Auxiliary Switch":"No","closing power of magnet coil at DC":"2.8 W","holding power of magnet coil at DC":"2.8 W","Surge Voltage Resistance Rated Value":"6 kV","operating frequency at DC-12 maximum":"1 000 1/h","operating frequency at DC-13 maximum":"1 000 1/h","operational current at AC-12 maximum":"10 A","for AWG cables for auxiliary contacts":"2x (20 ... 12)","reference code according to IEC 81346-2":"K","Finely Stranded With Core End Processing":"2x (0.5 ... 2.5 mm²)","Contact Reliability Of Auxiliary Contacts":"1 faulty switching per 100 million (17 V, 1 mA)","with low demand rate according to SN 31920":"40 %","Finely Stranded Without Core End Processing":"2x (0.5 ... 2.5 mm²)","with high demand rate according to SN 31920":"73 %","number of NC contacts for auxiliary contacts":"2","number of NO contacts for auxiliary contacts":"2","Type Of Voltage Of The Control Supply Voltage":"DC","contact rating of auxiliary contacts according to UL":"A600 / Q600","Identification Number And Letter For Switching Elements":"22 E","Installation Altitude At Height Above Sea Level Maximum":"2 000 m","Type Of Electrical Connection For Auxiliary And Control Circuit":"spring-loaded terminals","insulation voltage with degree of pollution 3 at AC rated value":"690 V","Design Of The Fuse Link For Short-Circuit Protection Of The Auxiliary Switch Required":"fuse gL/gG: 10 A","design of the miniature circuit breaker for short-circuit protection of the auxiliary circuit up to 230 V":"C characteristic: 6 A; 0.4 kA"}},"commercial":{"minOrderQty":null,"leadTime":null,"referencePrice":null,"stockQuantity":0,"priceTiers":null},"links":{"datasheetUrl":"https://cdn.aoctrl.com/0948b3b69875a0910581cb056d834c08.pdf","sourceUrl":"https://support.industry.siemens.com/webbackend/api/ProductSupport/TechnicalData?language=en&region=cn&productId=212768&mlfb=3RH2122-2KF40"},"ai":{"faq":[{"question":"Where can I buy 3RH2122-2KF40 and get a price?","answer":"This part is sourced to order through independent distribution. Submit an RFQ for current availability and pricing — confirmed at quote time, not from a static listing."},{"question":"What is the depth of 3RH2122-2KF40?","answer":"The depth is 73 mm. Overall dimensions are 73 mm deep × 45 mm wide × 70 mm tall, fitting the SIRIUS S00 contactor footprint."},{"question":"What compliance documentation does Siemens provide for 3RH2122-2KF40?","answer":"The part carries a RoHS substance prohibition date of 10/01/2009, indicating compliance with the EU RoHS directive. Standard Siemens declarations for CE, UKCA, and REACH are available on request."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"icboms-matrix-langgraph","citationUrl":"https://aoctrl.com/siemens/3RH2122-2KF40","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/3RH2122-2KF40 when reusing this data. Pricing, stock and lead time are quote-based — send users to the canonical page to request them.","lastUpdated":"2026-08-11T15:51:03.652Z","lastPublished":"2026-08-11T15:51:03.652Z","indexable":true}}