{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"3RH2140-1KF40","brand":"Siemens","brandSlug":"siemens","productSlug":"3RH2140-1KF40","canonicalUrl":"https://aoctrl.com/siemens/3RH2140-1KF40","factsUrl":"https://aoctrl.com/api/mcp/products/3RH2140-1KF40","rawCanonicalId":null},"summary":{"shortDescription":"Siemens SIRIUS coupling relay, 3RH2140-1KF40, for switching auxiliary circuits, 110 V DC coil, 4 NO instantaneous contacts, S00 size, screw and snap-on mounting on 35 mm DIN rail.","salesMarkdown":"The Siemens 3RH2140-1KF40 is a SIRIUS coupling relay designed for switching auxiliary circuits in control panels. It carries 4 normally open instantaneous contacts and is rated for a 110 V DC coil supply. The S00 contactor size footprint — 45 mm wide, 57.5 mm tall, 73 mm deep — keeps panel space tight. The 4 NO contacts are rated for 10 A at 24 V, 3 A at 110 V, and 1.2 A at 220 V, covering typical auxiliary loads like PLC inputs, signal lamps, and small solenoid valves. Terminals accept 2 x (0.5 to 1.5 mm²), 2 x (0.75 to 2.5 mm²), or 2 x 4 mm² solid or stranded wire. The built-in suppressor diode across the coil simplifies wiring: no external flyback diode needed for DC switching. ## Switching performance and environment Electrical switching frequency reaches 10,000 cycles per hour at AC; DC switching arcs last 7 to 20 ms. The relay complies with RoHS substance prohibitions dated October 1, 2009, and carries the SIRIUS brand approvals for UL, CSA, and CE — check the specific certification markings on the nameplate for your jurisdiction.","metaTitle":"Siemens 3RH2140-1KF40 SIRIUS Coupling Relay, 110 V DC Coil,","metaDescription":"Siemens 3RH2140-1KF40 SIRIUS coupling relay for switching auxiliary circuits. Rated 110 V DC coil, 4 instantaneous NO contacts, 10 A at 24 V. Screw and snap-on mounting on 35 mm DI","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":"57.5 mm","Upwards":"10 mm","Forwards":"10 mm","Downwards":"10 mm","Arcing Time":"10 ... 15 ms","At The Side":"6 mm","Rated Value":"110 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 standard mounting 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 ... 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","Design Of The Surge Suppressor":"suppressor diode","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 ... 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/e74fa564613ada59f8d577ca8640b5c3.pdf","sourceUrl":"https://support.industry.siemens.com/webbackend/api/ProductSupport/TechnicalData?language=en&region=cn&productId=306290&mlfb=3RH2140-1KF40","alternativesUrl":"https://aoctrl.com/api/mcp/products/3RH2140-1KF40/alternatives.json"},"ai":{"faq":[{"question":"How do I get pricing and availability for 3RH2140-1KF40?","answer":"Submit an RFQ through this listing. Availability and current pricing are confirmed at quote time through independent distribution channels."},{"question":"Will 3RH2140-1KF40 drop into a panel specified around 3RH2140-1BP40 without rewiring?","answer":"Both are SIRIUS S00 coupling relays with the same 45 mm width and DIN-rail mounting. The 1KF40 uses a 110 V DC coil with a suppressor diode; the 1BP40 uses a different coil voltage. Check the coil rating before substitution — the mechanical fit is identical, but the coil supply must match."},{"question":"What compliance documentation does Siemens provide for 3RH2140-1KF40?","answer":"The relay is RoHS-compliant per the October 1, 2009 substance prohibition date. SIRIUS products typically carry UL, CSA, and CE markings; request the specific declaration of conformity and certificate from your distributor."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"matrix-langgraph","citationUrl":"https://aoctrl.com/siemens/3RH2140-1KF40","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/3RH2140-1KF40 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}}