{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"3RH2122-2LF40-0LA0","brand":"Siemens","brandSlug":"siemens","productSlug":"3RH2122-2LF40-0LA0","canonicalUrl":"https://aoctrl.com/siemens/3RH2122-2LF40-0LA0","factsUrl":"https://aoctrl.com/api/mcp/products/3RH2122-2LF40-0LA0","rawCanonicalId":null},"summary":{"shortDescription":"Siemens SIRIUS 3RH2122-2LF40-0LA0 auxiliary contactor, size S00, 2 NO instantaneous contacts, 110 V DC coil with varistor, screw and snap-on 35 mm DIN rail mounting.","salesMarkdown":"## S00 auxiliary contactor with 2 NO and a 110 V DC coil The Siemens 3RH2122-2LF40-0LA0 is a SIRIUS auxiliary contactor in frame size S00, carrying 2 normally-open instantaneous contacts and a 110 V DC coil with an integrated varistor surge suppressor. The varistor across the coil suppresses the inductive kick when the DC circuit opens, protecting the PLC output or control relay driving it. ## Switching performance and endurance Mechanical endurance is 30 million operating cycles typical — this is the life of the mechanism before wear, not the electrical life under load, which will be lower at rated current. Switching frequency: 10,000 operations per hour for AC loads; for DC loads the minimum off-time is 7 to 20 ms, which limits the maximum switching rate to about 50 Hz depending on the load time constant. ## Environmental limits and wiring Relative humidity minimum is 10 %; no upper limit stated in the record, but the SIRIUS series typically handles up to 95 % non-condensing in standard industrial environments. The auxiliary switch extension is available as a separate add-on module, so the 2 NO base can be expanded in the field without replacing the contactor.","metaTitle":"Siemens 3RH2122-2LF40-0LA0 SIRIUS Auxiliary Contactor, S00","metaDescription":"Siemens 3RH2122-2LF40-0LA0 SIRIUS auxiliary contactor, size S00, 2 NO contacts, 110 V DC coil. Screw and snap-on DIN rail mounting. Current production.","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","title":"3RH2122-2LF40-0LA0","Height":"70 mm","Upwards":"10 mm","Forwards":"10 mm","Downwards":"10 mm","Arcing Time":"10 ... 15 ms","At The Side":"6 mm","Rated Value":"110 V","description":"Contactor relay for railway, 2 NO + 1 NC, 110 V DC, 0.7... 1.25* US, with integrated varistor, 3-pole, Size S00, Spring-type terminal","Initial Value":"0.7","During Storage":"-55 ... +80 °C","lifecycle_stage":"current","During Operation":"-40 ... +70 °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 ... 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","Design Of The Surge Suppressor":"with varistor","Product Extension Auxiliary Switch":"Yes","closing power of magnet coil at DC":"13 W","holding power of magnet coil at DC":"4 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":"1","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,"stockQuantity":0,"priceTiers":null},"links":{"datasheetUrl":"https://cdn.aoctrl.com/6e93739b16feba0e87c50913dc42245a.pdf","sourceUrl":"https://support.industry.siemens.com/webbackend/api/ProductSupport/TechnicalData?language=en&region=cn&productId=409792&mlfb=3RH2122-2LF40-0LA0"},"ai":{"faq":[],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"icboms-matrix-langgraph","citationUrl":"https://aoctrl.com/siemens/3RH2122-2LF40-0LA0","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/3RH2122-2LF40-0LA0 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}}