{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"3RH2122-2LB40-1AA0","brand":"Siemens","brandSlug":"siemens","productSlug":"3RH2122-2LB40-1AA0","canonicalUrl":"https://aoctrl.com/siemens/3RH2122-2LB40-1AA0","factsUrl":"https://aoctrl.com/api/mcp/products/3RH2122-2LB40-1AA0","rawCanonicalId":null},"summary":{"shortDescription":"Siemens SIRIUS coupling relay, 3RH2122-2LB40-1AA0, size S00, 24 VDC coil, 10 A rated, screw and snap-on 35 mm DIN rail, with varistor.","salesMarkdown":"The Siemens 3RH2122-2LB40-1AA0 is a SIRIUS coupling relay — a size S00 contactor-style relay for switching auxiliary circuits in control panels. The 24 VDC coil draws 2.8 W closing power, and a built-in varistor handles surge suppression — no external snubber needed for most PLC or relay logic outputs. Rated at 10 A at both 24 V and 230 V, this relay handles typical auxiliary loads — contactor coils, indicator lamps, solenoid valves — across common control voltages. At 60 V it carries 4.7 A, at 110 V it carries 3 A, and at 400 V it carries 3 A. The 690 V rating drops to 1 A, which still covers most pilot-duty circuits in 690 V panels. The relay measures 45 mm wide, 70 mm high, and 116 mm deep — the depth matters when the panel door or gland plate is tight. These are the numbers to check if you are packing relays into a crowded enclosure.","metaTitle":"Siemens 3RH2122-2LB40-1AA0 SIRIUS Coupling Relay, 24 VDC, 10","metaDescription":"Siemens SIRIUS 3RH2122-2LB40-1AA0 coupling relay for switching auxiliary circuits. 24 VDC coil, 10 A rated, screw and snap-on 35 mm DIN rail mounting. Active production. Available","metaKeywords":null},"attributes":{"series":null,"packageCase":null,"mountingType":null,"rohsStatus":null,"productStatus":"Active","categoryPath":["Contactors"],"specifications":{"Depth":"116 mm","Width":"45 mm","at AC":"10 000 1/h","at DC":"7 ... 20 ms","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","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":"standing, on horizontal 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":"with varistor","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","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":"21","Installation Altitude At Height Above Sea Level Maximum":"2 000 m","Of The Contactor With Added Auxiliary Switch Block Typical":"10 000 000","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","Of The Contactor With Added Electronically Optimized Auxiliary Switch Block Typical":"5 000 000","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,"priceTiers":null},"links":{"datasheetUrl":null,"sourceUrl":"https://support.industry.siemens.com/webbackend/api/ProductSupport/TechnicalData?language=en&region=cn&productId=71686&mlfb=3RH2122-2LB40-1AA0","alternativesUrl":"https://aoctrl.com/api/mcp/products/3RH2122-2LB40-1AA0/alternatives.json"},"ai":{"faq":[{"question":"What is the depth of this relay?","answer":"The depth is 116 mm. That is the dimension from the DIN rail mounting surface to the front of the relay — important for enclosure depth clearance."},{"question":"Will 3RH2122-2LB40-1AA0 drop into a panel specified for 3RH2122-1WB40?","answer":"Both are size S00 coupling relays on 35 mm DIN rail, so the footprint and mounting are the same. The key difference is the coil voltage: this unit is 24 VDC with a varistor, while the 1WB40 variant uses a different coil. Check your control voltage before swapping."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"matrix-langgraph","citationUrl":"https://aoctrl.com/siemens/3RH2122-2LB40-1AA0","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/3RH2122-2LB40-1AA0 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}}