{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"3RH1140-1KB40","brand":"Siemens","brandSlug":"siemens","productSlug":"3RH1140-1KB40","canonicalUrl":"https://aoctrl.com/siemens/3RH1140-1KB40","factsUrl":"https://aoctrl.com/api/mcp/products/3RH1140-1KB40","rawCanonicalId":null},"summary":{"shortDescription":"Siemens SIRIUS coupling relay, 3RH1140-1KB40, 4 NO contacts, 24 VDC coil, 10 A rated, screw and snap-on mounting, IP20 front.","salesMarkdown":"The Siemens 3RH1140-1KB40 is a SIRIUS coupling relay — a compact auxiliary contactor designed to switch control and signal circuits in industrial panels. It carries 4 normally-open instantaneous contacts rated 10 A at 24 V, with a 24 VDC coil drawing 2.3 W both on pickup and hold. For inductive loads like small contactor coils or solenoid valves, derate per the AC/DC switching curves: at 230 V AC the contacts are rated 6 A, at 400 V AC it drops to 3 A, and at 690 V AC it is 1 A. The part is built for that regime. A built-in varistor surge suppressor is integrated across the coil, so no external flyback diode is needed for DC switching. The coil holds at 24 VDC nominal; the 0.7 initial value and 1.25 full-scale value refer to pickup/dropout voltage thresholds relative to rated voltage. Shock resistance is 10g at 5 ms and 5g at 10 ms — adequate for most industrial panel environments but not for direct machine-mount on high-vibration equipment. The 3RH1140-1KB40 is the coupling relay variant; the functionally similar 3RT1015 series contactors share the same S00 frame and mounting footprint but lack the varistor and are intended for motor switching rather than auxiliary circuit isolation. ## Integration notes Wire termination accepts solid conductors: 2x 0.5 to 1.5 mm², 2x 0.75 to 2.5 mm², or 2x 4 mm² — screw terminals. Dimensions are 45 mm wide, 57.5 mm tall, 72 mm deep — fits standard DIN-rail enclosures with 45 mm per module spacing. The depth of 72 mm means it will clear most 80 mm deep enclosures but check against shallow 60 mm boxes. The part carries a reference code K per IEC 81346-2 (relay/contactor function) and RoHS compliance date of July 1, 2006, indicating it meets EU substance restrictions.","metaTitle":"Siemens 3RH1140-1KB40 SIRIUS Coupling Relay, 24 VDC, 10 A","metaDescription":"Siemens SIRIUS 3RH1140-1KB40 coupling relay for switching auxiliary circuits. 24 VDC coil, 10 A rated, 4 NO contacts, IP20 front, snap-on mounting. Current production.","metaKeywords":null},"attributes":{"series":null,"packageCase":null,"mountingType":null,"rohsStatus":null,"productStatus":null,"categoryPath":["Contactors"],"specifications":{"Depth":"72 mm","Solid":"2x (0.5 ... 1.5 mm²), 2x (0.75 ... 2.5 mm²), 2x 4 mm²","Width":"45 mm","Height":"57.5 mm","Rated Value":"24 V","Initial Value":"0.7","During Storage":"-55 ... +80 °C","Leading Contact":"0","lifecycle_stage":"current","During Operation":"-25 ... +60 °C","During Transport":"-55 ... +80 °C","Fastening Method":"screw and snap-on mounting","Full-Scale Value":"1.25","Shock Resistance":"10g / 5 ms and 5g / 10 ms","Delayed Switching":"0","Lagging Switching":"0","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","Product Brand Name":"SIRIUS","Contact Reliability":"one incorrect switching operation of 100 million switching operations (17 V, 1 mA)","Degree Of Pollution":"3","Product Designation":"Coupling relay for switching auxiliary circuits","at 24 V rated value":"10 A","Of Contactor Typical":"30 000 000","at 110 V rated value":"1 A","at 220 V rated value":"0.27 A","at 230 V rated value":"6 A","at 400 V rated value":"3 A","at 500 V rated value":"2 A","at 690 V rated value":"1 A","Instantaneous Contact":"4","For Auxiliary Contacts":"0","Make-Before-Break Switching":"0","Substance Prohibitance (Date)":"01.07.2006 00:00:00","Design Of The Surge Suppressor":"with varistor","protection class IP on the front":"IP20","Product Extension Auxiliary Switch":"No","closing power of magnet coil at DC":"2.3 W","holding power of magnet coil at DC":"2.3 W","reference code acc. to IEC 81346-2":"K","Surge Voltage Resistance Rated Value":"6 kV","at AWG cables for auxiliary contacts":"2x (20 ... 16), 2x (18 ... 14), 1x 12","operational current at AC-12 maximum":"10 A","with low demand rate acc. to SN 31920":"40 %","with high demand rate acc. to SN 31920":"75 %","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)","Touch Protection Against Electrical Shock":"finger-safe","Of Auxiliary Contacts Instantaneous Contact":"0","number of NC contacts for auxiliary contacts":"0","number of NO contacts for auxiliary contacts":"4","Type Of Voltage Of The Control Supply Voltage":"DC","B10 value with high demand rate acc. to SN 31920":"1 000 000; With 0.3 x Ie","Identification Number And Letter For Switching Elements":"40 E","Installation Altitude At Height Above Sea Level Maximum":"2 000 m","Required Spacing With Side-By-Side Mounting At The Side":"0 mm","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"}},"commercial":{"minOrderQty":null,"leadTime":null,"referencePrice":"$53.34","priceTiers":null},"links":{"datasheetUrl":null,"sourceUrl":"https://support.industry.siemens.com/webbackend/api/ProductSupport/TechnicalData?language=en&region=cn&productId=214031&mlfb=3RH1140-1KB40","alternativesUrl":"https://aoctrl.com/api/mcp/products/3RH1140-1KB40/alternatives.json"},"ai":{"faq":[{"question":"What is the mounting and wiring specification?","answer":"It mounts via screw or snap-on to DIN rail (S00 frame, 45 mm wide). Terminals accept 2x 0.5–1.5 mm², 2x 0.75–2.5 mm², or 2x 4 mm² solid conductor. The front is IP20 rated."},{"question":"Does this relay include surge suppression?","answer":"Yes, the surge suppressor design is a varistor integrated across the coil — no external diode needed for DC switching."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"matrix-langgraph","citationUrl":"https://aoctrl.com/siemens/3RH1140-1KB40","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/3RH1140-1KB40 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}}