{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"3RH2122-1HB40","brand":"Siemens","brandSlug":"siemens","productSlug":"3RH2122-1HB40","canonicalUrl":"https://aoctrl.com/siemens/3RH2122-1HB40","factsUrl":"https://aoctrl.com/api/mcp/products/3RH2122-1HB40","rawCanonicalId":null},"summary":{"shortDescription":"Siemens SIRIUS 3RH2122-1HB40 coupling relay, size S00, 24 V DC coil, 10 A rated current, 2 instantaneous contacts, screw and snap-on 35 mm DIN-rail mounting, 45 x 57.5 x 73 mm.","salesMarkdown":"## Auxiliary circuit relay in a S00 frame The 3RH2122-1HB40 is a SIRIUS coupling relay — a compact auxiliary contactor for switching control signals, pilot lamps, PLC inputs, and interlock circuits in industrial panels. For a 24 V DC control circuit, the full 10 A is available, which covers most solenoid valve banks and indicator loads on a single contact set. Mechanical service life is 30 million operations, and the AC switching frequency reaches 10,000 cycles per hour — this relay is designed for high-duty-cycle auxiliary circuits where a general-purpose ice-cube relay would wear out in months. The arcing time of 10-15 ms sets the minimum off-time between switching events to prevent contact welding. ## DIN-rail fit and panel clearance The 45 mm width means it occupies one standard modular unit (1 MU = 18 mm is typical for terminal blocks, but SIRIUS contactors use a wider pitch — this is a 2.5-MU-wide device). These are the minimum air gaps to adjacent metalwork or other devices for heat dissipation and arc flash containment. In a dense panel, plan for these gaps or use the SIRIUS busbar system that spaces devices automatically. This matters when installing in a sloped cabinet or on a swing frame where the rail is not perfectly vertical. ## Coil, contacts, and wiring In a cabinet with many such relays, the cumulative heat load adds up; at 50 relays, that is 140 W of continuous heat that must be ventilated or the ambient temperature inside the enclosure rises above the 60 °C operating limit. Two instantaneous contacts are provided — the catalog does not specify NO/NC configuration, so the contact arrangement must be verified from the product marking or wiring diagram on the side of the device. Degree of pollution 3 means the relay is rated for conductive pollution environments — typical in industrial panels where dust, humidity, or condensation can create tracking paths. The storage temperature range of -55 to +80 °C covers unheated warehouses and shipping containers. Sourced to order against the BOM quantity through independent distribution channels. The part is RoHS-compliant per the substance prohibition date of 10/01/2009, covering the EU RoHS directive.","metaTitle":"Siemens 3RH2122-1HB40 SIRIUS Coupling Relay, 24 V DC, 10 A","metaDescription":"Siemens 3RH2122-1HB40 SIRIUS coupling relay, 24 V DC coil, 10 A rated, S00 size, 2 contacts, DIN-rail mount. Active production, sourced to order.","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":"3RH2122-1HB40","Height":"57.5 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, 0.7... 1.25* US, Size S00, screw 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 ... 1.5 mm²), 2x (0.75 ... 2.5 mm²), 2x 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":"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 ... 16), 2x (18 ... 14), 2x 12","reference code according to IEC 81346-2":"K","Finely Stranded With Core End Processing":"2x (0.5 ... 1.5 mm²), 2x (0.75 ... 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 %","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":"screw-type 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":"$21.59","stockQuantity":0,"priceTiers":null},"links":{"datasheetUrl":"https://cdn.aoctrl.com/395e8389626e5c8f09b912b482894476.pdf","sourceUrl":"https://support.industry.siemens.com/webbackend/api/ProductSupport/TechnicalData?language=en&region=cn&productId=94905&mlfb=3RH2122-1HB40"},"ai":{"faq":[{"question":"Where can I buy 3RH2122-1HB40 and get a price?","answer":"Submit an RFQ for current pricing and availability — no stock-holding claim is made here, and lead time is confirmed at quote time."},{"question":"What is the mechanical service life of 3RH2122-1HB40?","answer":"The typical mechanical service life is 30,000,000 operations, with an AC switching frequency of 10,000 cycles per hour. This is a high-cycle auxiliary relay, suitable for applications where a general-purpose relay would fail prematurely."},{"question":"What compliance documentation does Siemens provide for 3RH2122-1HB40?","answer":"The part carries a RoHS substance prohibition date of 10/01/2009, indicating compliance with the EU RoHS directive. Standard Siemens documentation includes the declaration of conformity and product datasheet."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"icboms-matrix-langgraph","citationUrl":"https://aoctrl.com/siemens/3RH2122-1HB40","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/3RH2122-1HB40 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}}