{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"3RH2140-2LB40","brand":"Siemens","brandSlug":"siemens","productSlug":"3RH2140-2LB40","canonicalUrl":"https://aoctrl.com/siemens/3RH2140-2LB40","factsUrl":"https://aoctrl.com/api/mcp/products/3RH2140-2LB40","rawCanonicalId":null},"summary":{"shortDescription":"Siemens SIRIUS coupling relay, 3RH2140-2LB40, 24 VDC coil, 10 A rated, 4 N/O contacts, varistor suppression, screw/snap-on 35 mm DIN rail, size S00.","salesMarkdown":"The Siemens 3RH2140-2LB40 is a SIRIUS coupling relay sized S00, designed for switching auxiliary circuits in control panels. It carries 4 instantaneous N/O contacts and a 24 V DC coil rated at 2.8 W closing power, with a built-in varistor surge suppressor across the coil. This makes it straightforward to fit into tight panel layouts or retrofit into existing SIRIUS contactor assemblies. At 400 V AC it's rated 3 A, and at 690 V AC it's 1 A — these numbers matter when switching contactor coils or signal lamps fed from different line voltages. Mechanical endurance is 30 million operations typical. Electrical life at AC is 10,000 operations per hour. For DC circuits, ensure the load time constant doesn't exceed these windows to avoid contact welding. RoHS compliance date is 2009-10-01, covering the EU RoHS directive. The varistor surge suppressor is integrated — no external snubber needed for most inductive loads.","metaTitle":"Siemens 3RH2140-2LB40 SIRIUS Coupling Relay, 24 VDC Coil, 10","metaDescription":"Siemens SIRIUS 3RH2140-2LB40 coupling relay for auxiliary circuits. 24 VDC coil, 10 A rated, 4 N/O contacts, varistor suppression, DIN-rail mount. Active production. Sourced to ord","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","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","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 ... 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":"4","Relative Humidity Minimum":"10 %","Substance Prohibitance (Date)":"10/01/2009","Design Of The Surge Suppressor":"with varistor","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","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 NO contacts for auxiliary contacts":"4","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":"40 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,"priceTiers":null},"links":{"datasheetUrl":"https://cdn.aoctrl.com/53a57233747249d03ae1db9fe462ecb1.pdf","sourceUrl":"https://support.industry.siemens.com/webbackend/api/ProductSupport/TechnicalData?language=en&region=cn&productId=34793&mlfb=3RH2140-2LB40","alternativesUrl":"https://aoctrl.com/api/mcp/products/3RH2140-2LB40/alternatives.json"},"ai":{"faq":[{"question":"What is the depth and width of 3RH2140-2LB40?","answer":"Depth is 73 mm, width is 45 mm, height is 70 mm. It fits the SIRIUS S00 contactor footprint and mounts on 35 mm DIN rail."},{"question":"Will 3RH2140-2LB40 drop into a panel specified for 3RH2140-1BP40 without rewiring?","answer":"Both are SIRIUS S00 coupling relays with the same 45 mm width and DIN-rail mounting, so the mechanical fit is identical. The main difference is the coil voltage: the -2LB40 uses 24 V DC with varistor suppression, while the -1BP40 may have a different coil rating. If your panel is wired for 24 V DC, it will drop in without rewiring."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"matrix-langgraph","citationUrl":"https://aoctrl.com/siemens/3RH2140-2LB40","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/3RH2140-2LB40 when reusing this data. Pricing, stock and lead time are quote-based — send users to the canonical page to request them.","lastUpdated":"2026-09-02T08:15:54.622Z","lastPublished":"2026-09-02T08:15:54.622Z","indexable":true}}