{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"3RH2140-1SB40","brand":"Siemens","brandSlug":"siemens","productSlug":"3RH2140-1SB40","canonicalUrl":"https://aoctrl.com/siemens/3RH2140-1SB40","factsUrl":"https://aoctrl.com/api/mcp/products/3RH2140-1SB40","rawCanonicalId":null},"summary":{"shortDescription":"Siemens SIRIUS 3RH2140-1SB40 coupling relay for switching auxiliary circuits, 4 NO instantaneous contacts, 24 VDC coil, size S00, screw and snap-on mounting on 35 mm DIN rail.","salesMarkdown":"## What the 24 VDC coil and 4 NO contacts mean for your control circuit The 3RH2140-1SB40 is a SIRIUS coupling relay — a 4-pole normally-open auxiliary contactor designed to switch signal-level loads in control circuits, not motor power. The 24 VDC coil draws 1.6 W closing power, which is light enough that a standard PLC digital output or small control transformer can drive it without a separate interposing relay. At 24 V DC the contacts handle 10 A; at 220 V DC the rating falls to 1.2 A. This derating curve means the same relay can serve 24 V PLC I/O isolation and 230 V valve solenoids, but not a 480 V motor contactor coil without checking the inrush against the 3 A rating at 400 V. Built-in suppressor diode across the coil eliminates the need for an external flyback diode on DC circuits — one less component to place and wire. The pick-up threshold is 0.85× rated voltage (20.4 VDC) and the drop-out is 1.85× rated (44.4 VDC), giving a wide hysteresis that prevents chatter on a sagging 24 V bus.","metaTitle":"Siemens 3RH2140-1SB40 SIRIUS Coupling Relay, 4 NO, 24 VDC","metaDescription":"Siemens 3RH2140-1SB40 SIRIUS coupling relay, 4 NO contacts, 24 VDC coil, S00 size, 30M mechanical cycles. Active production, quoted to order. RoHS compliant.","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":"3RH2140-1SB40","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","description":"Coupling contactor relay, 4 NO 24 V DC, 0.85-1.85*US with integrated suppressor diode Size S00 screw 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 DIN 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","Design Of The Surge Suppressor":"suppressor diode","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","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","for AWG cables for auxiliary contacts":"2x (20 ... 16), 2x (18 ... 14), 2x 12","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,"stockQuantity":0,"priceTiers":null},"links":{"datasheetUrl":"https://cdn.aoctrl.com/d27ecfba996f21a1f418f20108fead24.pdf","sourceUrl":"https://support.industry.siemens.com/webbackend/api/ProductSupport/TechnicalData?language=en&region=cn&productId=458215&mlfb=3RH2140-1SB40"},"ai":{"faq":[{"question":"What is the mechanical endurance of this coupling relay?","answer":"30 million mechanical cycles typical. This is the mechanical life — electrical life will be lower depending on the switched load and switching frequency (rated 10,000 operations per hour AC)."},{"question":"What compliance documentation does Siemens provide for 3RH2140-1SB40?","answer":"RoHS compliance is confirmed with a substance prohibition date of 10/01/2009. Standard Siemens documentation includes the RoHS declaration; REACH and UL documentation are not listed in the spec record but are typically available from Siemens upon request."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"icboms-matrix-langgraph","citationUrl":"https://aoctrl.com/siemens/3RH2140-1SB40","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/3RH2140-1SB40 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}}