{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"3RH2122-2QB40","brand":"Siemens","brandSlug":"siemens","productSlug":"3RH2122-2QB40","canonicalUrl":"https://aoctrl.com/siemens/3RH2122-2QB40","factsUrl":"https://aoctrl.com/api/mcp/products/3RH2122-2QB40","rawCanonicalId":null},"summary":{"shortDescription":"Siemens SIRIUS coupling relay 3RH2122-2QB40, size S00, 24 VDC coil, 2 NO contacts, 10 A rated current, screw and snap-on mounting on 35 mm rail.","salesMarkdown":"The Siemens 3RH2122-2QB40 is a SIRIUS coupling relay — a size S00 auxiliary contactor designed to switch auxiliary circuits in a control panel. It carries 2 instantaneous NO contacts rated for 10 A at 24 V rated value, which means it can handle the typical pilot-duty loads (PLC outputs, indicator lamps, small contactor coils) without an intermediate relay. The coil pulls 2.8 W closing power on DC, so the backplane or PLC output driving it needs to source that inrush. The 45 mm width and 73 mm depth fit the S00 footprint — common in compact control cabinets. Mounting position allows ±180° rotation on a vertical surface and ±22.5° tilt forward/backward, so you can orient it to fit tight gland plates or wireways. Clearances: 10 mm upward, 10 mm forward, 10 mm downward, 6 mm at the side. ## Switching capability and surge suppression Built-in varistor surge suppressor across the coil — no external snubber needed for inductive loads like contactor coils or solenoid valves. The contacts are rated for switching at 10 000 operations per hour (AC) and the arcing time runs 10 to 15 ms, so it keeps up with fast-cycle applications like stamping presses or conveyor indexing. At DC the on-time can be 7 to 20 ms; the varistor clips the turn-off spike, extending contact life on DC loads.","metaTitle":"Siemens 3RH2122-2QB40 SIRIUS Coupling Relay, 24 VDC, 10 A, 2","metaDescription":"Siemens 3RH2122-2QB40 SIRIUS coupling relay, 24 VDC coil, 10 A rated current, 2 instantaneous contacts, screw and snap-on mounting, current lifecycle. Quoted to order against RFQ.","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","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 standard mounting 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":"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":"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,"priceTiers":null},"links":{"datasheetUrl":"https://cdn.aoctrl.com/189e99966891cb04a9742b2381abd0f4.pdf","sourceUrl":"https://support.industry.siemens.com/webbackend/api/ProductSupport/TechnicalData?language=en&region=cn&productId=467882&mlfb=3RH2122-2QB40","alternativesUrl":"https://aoctrl.com/api/mcp/products/3RH2122-2QB40/alternatives.json"},"ai":{"faq":[{"question":"What is the width and depth of 3RH2122-2QB40?","answer":"Width is 45 mm, depth is 73 mm — standard S00 size for DIN-rail mounting."},{"question":"Will 3RH2122-2QB40 drop into a panel that was specified around 3RH2122-1WB40 without rewiring?","answer":"Both are S00 size with the same mounting footprint (screw/snap-on on 35 mm rail), so physical fit is identical. The difference is in the coil voltage and contact arrangement — verify the 1WB40's coil rating and contact count against this 24 VDC 2 NO variant before dropping it in."},{"question":"What compliance documentation does Siemens provide for 3RH2122-2QB40?","answer":"The part carries a substance prohibitance date of 10/01/2009, indicating RoHS compliance. Standard Siemens documentation includes the declaration of conformity and CE marking; check the product support page for the specific IEC/UL certificates tied to this order code."},{"question":"Where can I buy 3RH2122-2QB40 and how is it quoted?","answer":"Sourced and quoted to order against an RFQ through independent distribution. Availability and current pricing are confirmed at quote time — submit an RFQ for a firm price and lead time."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"matrix-langgraph","citationUrl":"https://aoctrl.com/siemens/3RH2122-2QB40","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/3RH2122-2QB40 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}}