{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"3RH2122-2BM40","brand":"Siemens","brandSlug":"siemens","productSlug":"3RH2122-2BM40","canonicalUrl":"https://aoctrl.com/siemens/3RH2122-2BM40","factsUrl":"https://aoctrl.com/api/mcp/products/3RH2122-2BM40","rawCanonicalId":null},"summary":{"shortDescription":"Siemens SIRIUS 3RH2122-2BM40 auxiliary contactor, size S00, 2 NO instantaneous contacts, screw and snap-on 35 mm DIN rail mounting, 73 mm depth, 45 mm width.","salesMarkdown":"## Panel fit and mounting flexibility The 3RH2122-2BM40 is a SIRIUS size S00 auxiliary contactor — the smallest frame in the family, built for high-density control panels where every millimeter counts. That means you can orient it to fit cable entry paths or clearance around other gear without reworking the rail layout. These are the minimum air gaps to maintain rated isolation — useful when packing multiple contactors side-by-side in a row. This auxiliary contactor carries 2 NO instantaneous contacts and its current rating varies significantly with the switched voltage — a detail that matters when you're coordinating with PLC outputs or pilot devices running on different control voltages. On the DC side, at 24 V it handles 10 A, but at 220 V DC the rating falls to 1.2 A, and at 600 V DC it's just 0.26 A. The arcing time is 10-15 ms, and the closing/holding power of the DC magnet coil is 4 W. That's built for high-duty applications like conveyor interlocking or machine tool auxiliary circuits where the contactor cycles every few seconds. ## Environmental and compliance specs The substance prohibition date is listed as 10/01/2009, aligning with RoHS and REACH compliance expectations for this generation of SIRIUS gear. The product extension for auxiliary switches is supported, so you can add contact blocks downstream if the 2 NO base isn't enough.","metaTitle":"Siemens 3RH2122-2BM40 SIRIUS Auxiliary Contactor, S00","metaDescription":"Siemens 3RH2122-2BM40 SIRIUS auxiliary contactor, size S00, 2 NO instantaneous contacts. Rated 10 A at 230 V AC. Screw and snap-on 35 mm DIN rail mount.","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 ... 13 ms","title":"3RH2122-2BM40","Height":"70 mm","Upwards":"10 mm","Forwards":"10 mm","Downwards":"10 mm","Arcing Time":"10 ... 15 ms","At The Side":"6 mm","Rated Value":"220 V","description":"Contactor relay, 2 NO + 2 NC, 220 V DC, Size S00, Spring-type terminal","Initial Value":"0.8","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":"1.1","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":"Auxiliary contactor","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":"Yes","closing power of magnet coil at DC":"4 W","holding power of magnet coil at DC":"4 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","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,"stockQuantity":0,"priceTiers":null},"links":{"datasheetUrl":"https://cdn.aoctrl.com/35219d2f550aa3e7375902ff322c111b.pdf","sourceUrl":"https://support.industry.siemens.com/webbackend/api/ProductSupport/TechnicalData?language=en&region=cn&productId=471173&mlfb=3RH2122-2BM40"},"ai":{"faq":[{"question":"What is the 3RH2122-2BM40 used for?","answer":"It's a SIRIUS size S00 auxiliary contactor with 2 NO contacts, used to switch control signals in motor starter circuits, PLC output interposing, and machine tool auxiliary circuits. The 10 A rating at 230 V AC covers most 24-230 V control loads, and the 30 million mechanical cycles suit high-duty applications."},{"question":"How can I order the 3RH2122-2BM40 and check availability?","answer":"This part is sourced through independent distribution and quoted to order against your BOM quantity. No stock-holding claim is made; availability is verified per request."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"icboms-matrix-langgraph","citationUrl":"https://aoctrl.com/siemens/3RH2122-2BM40","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/3RH2122-2BM40 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}}