{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"3RH2122-2MB40-0KT0","brand":"Siemens","brandSlug":"siemens","productSlug":"3RH2122-2MB40-0KT0","canonicalUrl":"https://aoctrl.com/siemens/3RH2122-2MB40-0KT0","factsUrl":"https://aoctrl.com/api/mcp/products/3RH2122-2MB40-0KT0","rawCanonicalId":null},"summary":{"shortDescription":"Siemens SIRIUS 3RH2122-2MB40-0KT0 coupling relay, S00 frame, 24 VDC coil, 10 A rated current, 2 NO contacts, screw and snap-on mounting on 35 mm DIN rail.","salesMarkdown":"## What this coupling relay does in a control panel The 3RH2122-2MB40-0KT0 is a SIRIUS coupling relay — essentially an auxiliary contactor that bridges the PLC output to the main contactor coil or other loads in the control cabinet. It's sized in the S00 frame, the smallest footprint in the SIRIUS family, so it fits where panel space is tight. The coil pulls 24 VDC at 1.6 W both on pickup and hold — no inrush spike to sag the DC bus. That matters when you're running a string of these off a single 24 VDC power supply; the steady-state draw is predictable and low. The 2 NO contact configuration gives you two isolated signal paths per relay. ## Mounting and panel fit — DIN rail and clearances Mounts on 35 mm standard DIN rail with either screw or snap-on fastening. Dimensions are 70 mm high, 45 mm wide, 73 mm deep. The S00 frame keeps the width under 50 mm, so you can pack several side-by-side on a single DIN rail segment. ## Lifecycle and sourcing — still in active production Sourced to order against the BOM quantity through independent distribution.","metaTitle":"Siemens 3RH2122-2MB40-0KT0 SIRIUS coupling relay, 24 VDC","metaDescription":"Siemens SIRIUS 3RH2122-2MB40-0KT0 coupling relay for switching auxiliary circuits. 24 VDC coil, 10 A rated current, S00 frame.","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":"5 ... 20 ms","title":"3RH2122-2MB40-0KT0","Height":"70 mm","Upwards":"10 mm","Forwards":"10 mm","Downwards":"10 mm","Arcing Time":"10 ... 15 ms","At The Side":"6 mm","Rated Value":"24 V","description":"Coupling contactor relay, 2 NO + 2 NC 24 V DC, 0.85... 1.85* US, Size S00, Spring-type terminal","Initial Value":"0.85","During Storage":"-55 ... +80 °C","lifecycle_stage":"current","During Operation":"-25 ... +50 °C","Fastening Method":"screw and snap-on mounting onto 35 mm standard mounting rail","Full-Scale Value":"1.85","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","Product Extension Auxiliary Switch":"No","closing power of magnet coil at DC":"1.6 W","holding power of magnet coil at DC":"1.6 W","Surge Voltage Resistance Rated Value":"6 kV","at AWG cables for auxiliary contacts":"2x (20 ... 12)","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","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/7ad0c605791db786a3e8a2653aa4a12e.pdf","sourceUrl":"https://support.industry.siemens.com/webbackend/api/ProductSupport/TechnicalData?language=en&region=cn&productId=526763&mlfb=3RH2122-2MB40-0KT0"},"ai":{"faq":[{"question":"What are the key ratings for 3RH2122-2MB40-0KT0?","answer":"24 VDC coil drawing 1.6 W, 10 A rated current at 24 V for the auxiliary contacts, 2 NO contact configuration, S00 frame size, and a mechanical life of 30 million operations typical."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"icboms-matrix-langgraph","citationUrl":"https://aoctrl.com/siemens/3RH2122-2MB40-0KT0","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/3RH2122-2MB40-0KT0 when reusing this data. Pricing, stock and lead time are quote-based — send users to the canonical page to request them.","lastUpdated":"2026-07-22T19:47:38.189Z","lastPublished":"2026-07-22T19:47:38.189Z","indexable":true}}