{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"3RH2122-2KG40-0LA4","brand":"Siemens","brandSlug":"siemens","productSlug":"3RH2122-2KG40-0LA4","canonicalUrl":"https://aoctrl.com/siemens/3RH2122-2KG40-0LA4","factsUrl":"https://aoctrl.com/api/mcp/products/3RH2122-2KG40-0LA4","rawCanonicalId":null},"summary":{"shortDescription":"Siemens SIRIUS 3RH2122-2KG40-0LA4 auxiliary contactor, size S00, 2 NO instantaneous contacts, screw and snap-on mounting for 35 mm DIN rail, 45 mm wide, 116 mm deep.","salesMarkdown":"## S00 frame, 2 NO, and what the DC switching curve means The 3RH2122-2KG40-0LA4: The steep derating reflects the DC arc extinction challenge — unlike AC, there is no natural zero-crossing, so the contact gap must stretch the arc until it extinguishes. ## Mounting flexibility and panel integration This matters when packing multiple contactors side-by-side in a panel — the 6 mm side gap is the minimum to prevent inter-device arcing at the rated pollution degree 3. The coil is fitted with a suppressor diode internally — no external snubber needed for DC control circuits. The product extension auxiliary switch is available, meaning additional contact blocks can be stacked onto this base unit without removing it from the rail.","metaTitle":"Siemens 3RH2122-2KG40-0LA4 SIRIUS Auxiliary Contactor, S00","metaDescription":"Siemens 3RH2122-2KG40-0LA4 SIRIUS auxiliary contactor, size S00, 2 NO contacts, 45 mm wide. Rated switching capacity from 10 A at 24 V to 0.26 A at 600 V DC.","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":"3RH2122-2KG40-0LA4","Height":"70 mm","Upwards":"10 mm","Forwards":"10 mm","Downwards":"10 mm","Arcing Time":"10 ... 15 ms","At The Side":"6 mm","Rated Value":"125 V","description":"Contactor relay railway, 2 NO + 1 NC 125 V DC, 0.7... 1.25* US, with integrated suppressor diode, Size S00, Spring-type terminal installation on standard mounting rail optimized (20G) suitable for PLC outputs","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":"suppressor diode","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/03fcf14ed22a4cdad6fc12df37740f03.pdf","sourceUrl":"https://support.industry.siemens.com/webbackend/api/ProductSupport/TechnicalData?language=en&region=cn&productId=438911&mlfb=3RH2122-2KG40-0LA4"},"ai":{"faq":[{"question":"What is the DC switching capacity of 3RH2122-2KG40-0LA4 at different voltages?","answer":"At 125 V the rated value is 0.7 A. This derating curve must be respected for reliable DC load switching — the contact gap is sized for the worst-case arc at the highest voltage."},{"question":"What mounting clearances are required around 3RH2122-2KG40-0LA4?","answer":"These are the air gaps needed to maintain the rated pollution degree 3 insulation between adjacent devices."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"icboms-matrix-langgraph","citationUrl":"https://aoctrl.com/siemens/3RH2122-2KG40-0LA4","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/3RH2122-2KG40-0LA4 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}}