{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"3RH2140-1MB40-0KT0","brand":"Siemens","brandSlug":"siemens","productSlug":"3RH2140-1MB40-0KT0","canonicalUrl":"https://aoctrl.com/siemens/3RH2140-1MB40-0KT0","factsUrl":"https://aoctrl.com/api/mcp/products/3RH2140-1MB40-0KT0","rawCanonicalId":null},"summary":{"shortDescription":"Siemens SIRIUS 3RH2140-1MB40-0KT0 coupling relay, 24 VDC coil, 4 NO instantaneous contacts, size S00, screw and snap-on mounting for 35 mm DIN rail.","salesMarkdown":"The Siemens SIRIUS 3RH2140-1MB40-0KT0 is a coupling relay for switching auxiliary circuits. The coil pulls 1.6 W to close and holds at 1.6 W. That matters when you're squeezing it into a crowded panel on a retrofit. Dimensions are 45 mm wide, 57.5 mm tall, 73 mm deep — it's a compact block that fits alongside S00 contactors in a common rail layout. That's fast enough for most relay-logic and PLC-interposing duties, but if you're switching inductive loads, plan for the arc duration in your timing budget. DC switching is specified by pulse duration of 5 to 20 ms — a reminder that DC arcs don't self-extinguish like AC, so the relay is designed to clear quickly. Current ratings drop as voltage rises — a common derating curve for air-break contacts. At 24 V you get the full 10 A; at 230 V it's still 10 A; at 400 V it's 3 A; at 690 V it's 1 A. If you're using this relay to switch a control transformer primary at 400 V, the 3 A limit is the one to watch, not the headline 10 A number. Relative humidity minimum is 10 % — no upper limit stated, but the pollution degree 3 rating implies it can handle typical factory floor humidity without creepage issues. Wire termination accepts 2x (0.5 to 1.5 mm²), 2x (0.75 to 2.5 mm²), or 2x 4 mm² solid or stranded. That's flexible enough for most control wiring — you can daisy-chain two conductors per terminal for commoning. The 4 mm² option lets you run a heavier feed wire if the relay is some distance from the power supply. These are the minimum air gaps to maintain for safe operation at rated voltage. In a dense panel, you'll want to respect the 6 mm side clearance to adjacent devices, especially if they generate heat or arc. The 3RH2140-1MB40-0KT0 does not have a built-in auxiliary switch extension — it's a bare 4-pole relay. If you need additional signaling contacts, you'll add a separate auxiliary switch block from the SIRIUS range. The product extension auxiliary switch field is marked 'No', so plan your feedback wiring accordingly.","metaTitle":"Siemens 3RH2140-1MB40-0KT0 SIRIUS Coupling Relay, 24 VDC, 4","metaDescription":"Siemens SIRIUS 3RH2140-1MB40-0KT0 coupling relay, 24 VDC coil, 4 NO contacts rated 10 A at 24 V. Current lifecycle stage. Snap-on 35 mm DIN rail. Available to order against RFQ.","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","Height":"57.5 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":"0.85","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 ... 1.5 mm²), 2x (0.75 ... 2.5 mm²), 2x 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 ... 16), 2x (18 ... 14), 2x 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 ... 1.5 mm²), 2x (0.75 ... 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 %","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":"screw-type 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/f2bdb9fe9935fb27a0f9cfcdae62b45f.pdf","sourceUrl":"https://support.industry.siemens.com/webbackend/api/ProductSupport/TechnicalData?language=en&region=cn&productId=6734&mlfb=3RH2140-1MB40-0KT0","alternativesUrl":"https://aoctrl.com/api/mcp/products/3RH2140-1MB40-0KT0/alternatives.json"},"ai":{"faq":[{"question":"Will 3RH2140-1MB40-0KT0 drop into a panel specified around 3RH2122-1WB40 without rewiring?","answer":"Both are SIRIUS S00-size coupling relays sharing the same 45 mm width and DIN-rail mounting footprint, so mechanical fit is identical. The 3RH2140-1MB40-0KT0 has 4 NO contacts versus the 3RH2122-1WB40's different contact arrangement — check your wiring diagram to confirm the contact scheme matches before substituting."},{"question":"What is the depth of 3RH2140-1MB40-0KT0?","answer":"73 mm, measured from the DIN-rail mounting surface to the front of the housing. That's the dimension that matters for enclosure depth clearance."},{"question":"What compliance documentation does this relay carry?","answer":"The part is a Siemens SIRIUS product, which typically carries CE, UL, CSA, and RoHS compliance. The substance prohibition date of 10/01/2009 indicates RoHS compliance before that deadline. For specific certificates or declaration of conformity, the manufacturer's documentation portal is the source."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"matrix-langgraph","citationUrl":"https://aoctrl.com/siemens/3RH2140-1MB40-0KT0","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/3RH2140-1MB40-0KT0 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}}