{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"3RH2122-2VB40","brand":"Siemens","brandSlug":"siemens","productSlug":"3RH2122-2VB40","canonicalUrl":"https://aoctrl.com/siemens/3RH2122-2VB40","factsUrl":"https://aoctrl.com/api/mcp/products/3RH2122-2VB40","rawCanonicalId":null},"summary":{"shortDescription":"Siemens SIRIUS 3RH2122-2VB40 coupling relay, size S00, 24 VDC coil with integrated diode suppression, 2 NO + 2 NC contacts, screw and snap-on mounting on 35 mm DIN rail, 73 mm depth, 45 mm width.","salesMarkdown":"## SIRIUS S00 coupling relay — what it is and where it lives The Siemens 3RH2122-2VB40 is a SIRIUS coupling relay in the S00 contactor frame size — essentially an auxiliary contactor block with a 24 VDC coil and a built-in diode surge suppressor across the coil terminals. It mounts via screw or snap-on onto a 35 mm DIN rail, and the mounting position allows ±180° rotation on a vertical surface plus ±22.5° tilt forward/backward — useful when you're squeezing it into a crowded panel and need to orient the wiring access. ## Switching capacity across the voltage range Rated for 10 A at both 24 V and 230 V, which covers most control-circuit and small-load switching in a 24 VDC panel or a 230 VAC lighting/heater circuit. At 400 V it handles 3 A, and at 690 V it still switches 1 A — so it can handle contactor coil suppression or signal isolation in higher-voltage auxiliary circuits without derating to zero. The mechanical life is 30 million operations typical, and the arcing time sits between 10 and 15 ms — both figures that matter when you're counting cycles on a frequently cycled valve or conveyor interlock. ## Panel fit and environmental limits Dimensions are 73 mm deep × 45 mm wide × 70 mm tall — the 45 mm width is a single 9 mm module equivalent on a DIN rail, so it takes up one standard slot in a Siemens panel layout. Clearance to adjacent devices: 10 mm upwards, forwards, and downwards, and 6 mm at the sides — tight enough for dense layouts but you still need that breathing room for heat dissipation. Operates from -25 °C to +50 °C, stores from -55 °C to +80 °C, and is rated for pollution degree 3 — so it's fine in a typical industrial control cabinet, not a clean room. ## Sourcing and lifecycle RoHS compliance date is 10/01/2009, so it meets the EU substance restrictions for new installations.","metaTitle":"Siemens 3RH2122-2VB40 SIRIUS coupling relay, S00, 24 VDC","metaDescription":"Siemens 3RH2122-2VB40 SIRIUS coupling relay, size S00, 24 VDC coil, 10 A switching at 230 V. Screw and snap-on 35 mm DIN rail.","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":"20 ... 80 ms","title":"3RH2122-2VB40","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, with integrated diode, 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 DIN 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","Design Of The Surge Suppressor":"diode","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","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/22dae0faf4cf2c56eb130718c3bd3584.pdf","sourceUrl":"https://support.industry.siemens.com/webbackend/api/ProductSupport/TechnicalData?language=en&region=cn&productId=508502&mlfb=3RH2122-2VB40"},"ai":{"faq":[{"question":"What is the closest alternative to 3RH2122-2VB40 in the SIRIUS family?","answer":"The 3RH2122-2VB40 is a specific variant with a 24 VDC coil and integrated diode suppression. Other SIRIUS S00 coupling relays differ by coil voltage (e.g., 24 VAC, 110 V, 230 V) or by surge suppressor type (RC, varistor). No pin-compatible direct substitute exists without changing the coil voltage or suppression method."},{"question":"How do I get pricing and availability for 3RH2122-2VB40?","answer":"Submit an RFQ with your target quantity. We source through authorized distribution channels and confirm current pricing and lead time at quote time — no stock-holding claim, but we can quote against your BOM line."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"icboms-matrix-langgraph","citationUrl":"https://aoctrl.com/siemens/3RH2122-2VB40","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/3RH2122-2VB40 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}}