{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"3RH2140-2MB40-0KT0","brand":"Siemens","brandSlug":"siemens","productSlug":"3RH2140-2MB40-0KT0","canonicalUrl":"https://aoctrl.com/siemens/3RH2140-2MB40-0KT0","factsUrl":"https://aoctrl.com/api/mcp/products/3RH2140-2MB40-0KT0","rawCanonicalId":null},"summary":{"shortDescription":"Siemens SIRIUS 3RH2140-2MB40-0KT0 coupling relay, size S00, 24 VDC coil, 4 NO instantaneous contacts, 10 A rated current at 24 V, screw and snap-on mounting on 35 mm DIN rail.","salesMarkdown":"## Coupling relay for auxiliary circuit switching The Siemens 3RH2140-2MB40-0KT0 is a SIRIUS coupling relay designed to switch auxiliary circuits in control panels. ## Contact ratings and switching capability This voltage-dependent current curve means the relay is best suited for low-voltage auxiliary loads — PLC outputs, signal lamps, solenoid valves — rather than high-voltage power switching. ## Coil drive and environmental limits The 24 VDC coil picks up at 85 % of rated voltage (20.4 V) and drops out at 185 % (44.4 V) — the wide dropout margin prevents nuisance drop-out on a sagging bus. Coil power is a constant 1.6 W DC, so no inrush peak to size the power supply for. Pollution degree 3 means it tolerates conductive pollution in industrial control cabinets — no conformal coating required for typical panel environments. ## Mounting and clearance requirements These spacings ensure arc quenching and heat dissipation — pack tighter and the relay may overheat or flash over. No auxiliary switch extension is available on this variant — the 4 NO contacts are fixed. For applications needing additional signaling, a separate auxiliary contact block from the SIRIUS range would be added externally.","metaTitle":"Siemens 3RH2140-2MB40-0KT0 SIRIUS Coupling Relay, 24 VDC","metaDescription":"Siemens 3RH2140-2MB40-0KT0 SIRIUS coupling relay, 24 VDC coil, 4 NO contacts, 10 A at 24 V. Size S00, screw/snap-on mounting.","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":"5 ... 20 ms","title":"3RH2140-2MB40-0KT0","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","description":"Coupling contactor relay, 4 NO 24 V DC, 0.85... 1.85* US, Size S00, Spring-type terminal","Initial Value":"0.85","During Storage":"-55 ... +80 °C","lifecycle_stage":"current","During Operation":"-25 ... +50 °C","Fastening Method":"screw and snap-on mounting onto 35 mm standard mounting rail","Full-Scale Value":"1.85","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","Product Extension Auxiliary Switch":"No","closing power of magnet coil at DC":"1.6 W","holding power of magnet coil at DC":"1.6 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,"stockQuantity":0,"priceTiers":null},"links":{"datasheetUrl":"https://cdn.aoctrl.com/ec1a560017c3ba8cace516b1dd8f9414.pdf","sourceUrl":"https://support.industry.siemens.com/webbackend/api/ProductSupport/TechnicalData?language=en&region=cn&productId=515662&mlfb=3RH2140-2MB40-0KT0"},"ai":{"faq":[{"question":"What is the 3RH2140-2MB40-0KT0 used for?","answer":"It is a coupling relay for switching auxiliary circuits — typically used to interface PLC digital outputs with higher-current loads, to isolate control signals from power circuits, or to multiply contact capacity in a control panel. The 4 NO contacts handle up to 10 A at 24 VDC or 230 VAC."},{"question":"What compliance documentation does Siemens provide for 3RH2140-2MB40-0KT0?","answer":"The relay is RoHS compliant with a substance prohibition date of October 1, 2009. Standard Siemens documentation includes a CE declaration of conformity and a UL/CSA file number — these are available on request with the order."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"icboms-matrix-langgraph","citationUrl":"https://aoctrl.com/siemens/3RH2140-2MB40-0KT0","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/3RH2140-2MB40-0KT0 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}}