{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"3RT2027-2KA40","brand":"Siemens","brandSlug":"siemens","productSlug":"3RT2027-2KA40","canonicalUrl":"https://aoctrl.com/siemens/3RT2027-2KA40","factsUrl":"https://aoctrl.com/api/mcp/products/3RT2027-2KA40","rawCanonicalId":null},"summary":{"shortDescription":"Siemens SIRIUS coupling contactor, size S0, 3RT2027-2KA40, 24 VDC coil, spring-type terminals, 45 mm width, 107 mm depth.","salesMarkdown":"The Siemens 3RT2027-2KA40 is a SIRIUS coupling contactor in size S0 — a compact, DIN-rail-mountable switching device designed for isolating and switching DC control circuits, typically between a PLC output module and a downstream load or as an interface between different voltage domains in a panel. It is rated for 10 A at 24 V DC and 2 A at 48 V DC, with a DC switching capacity that drops to 0.3 A at 220 V DC — so the buyer needs to match the contactor's DC-13 or resistive rating to the actual load voltage and current, not just the coil voltage. The coil is 24 V DC, and the contactor is fitted with spring-type terminals — cage-clamp style — which speeds wiring and eliminates screw-torque checks on the line. At 45 mm wide, 102 mm high, and 107 mm deep, it fits a standard S0 footprint and leaves room for adjacent devices on the same DIN rail. Wire range: solid or stranded 1 … 10 mm², with dual-wire capability 2x (0.5 … 2.5 mm²). Spring terminals accept ferruled or solid conductors — strip length follows the manufacturer's recommendation for the terminal type. ## Switching performance and lifecycle Electrical switching frequency depends on the duty category: up to 1,000 operations per hour at AC-1 (resistive), 750/h at AC-2 and AC-3 (motor starting/running), and 250/h at AC-4 (plugging/inching). Arcing time is 10 … 10 ms, and the DC make/break time is 19 … 21 ms — consistent with a standard DC contactor response. The contactor has no built-in auxiliary switch — if feedback or status signaling is needed, a separate auxiliary contact block must be added.","metaTitle":"Siemens 3RT2027-2KA40 SIRIUS Coupling Contactor, S0 Size, 24","metaDescription":"Siemens 3RT2027-2KA40 SIRIUS coupling contactor, size S0, 24 VDC coil, spring-type terminals, 10 A at 24 VDC. Current lifecycle stage. Sourced to order against RFQ.","metaKeywords":null},"attributes":{"series":null,"packageCase":null,"mountingType":null,"rohsStatus":null,"productStatus":"Active","categoryPath":["Contactors"],"specifications":{"Depth":"107 mm","Solid":"1 ... 10 mm²","Width":"45 mm","at DC":"19 ... 21 ms","Height":"102 mm","Upwards":"10 mm","Forwards":"10 mm","Stranded":"1 ... 10 mm²","Downwards":"10 mm","Arcing Time":"10 ... 10 ms","At The Side":"6 mm","Rated Value":"12 V","Initial Value":"0.7","During Storage":"-55 ... +80 °C","Of Magnet Coil":"Spring-type terminals","at AC-1 maximum":"1 000 1/h","at AC-2 maximum":"750 1/h","at AC-3 maximum":"750 1/h","at AC-4 maximum":"250 1/h","lifecycle_stage":"current","Auxiliary Switch":"No","During Operation":"-25 ... +60 °C","Fastening Method":"screw and snap-on mounting onto 35 mm DIN rail according to DIN EN 60715","Full-Scale Value":"1.25","at AC-3e maximum":"750 1/h","For Main Contacts":"18 ... 8","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":"S0","Solid Or Stranded":"2x (0.5 ... 2.5 mm²)","Product Brand Name":"SIRIUS","Product Designation":"Coupling contactor","at 24 V rated value":"10 A","at 48 V rated value":"2 A","at 60 V rated value":"2 A","Of Contactor Typical":"10 000 000","at 110 V rated value":"1 A","at 125 V rated value":"0.9 A","at 220 V rated value":"0.3 A","at 230 V rated value":"5 hp","at 400 V rated value":"3 A","at 440 V rated value":"0.6 A","at 480 V rated value":"27 A","at 500 V rated value":"2 A","at 600 V rated value":"27 A","at 690 V rated value":"1 A","Side-By-Side Mounting":"Yes","For Auxiliary Contacts":"20 ... 14","For Main Current Circuit":"spring-loaded terminals","at 110/120 V rated value":"2 hp","at 200/208 V rated value":"10 hp","at 220/230 V rated value":"10 hp","at 460/480 V rated value":"20 hp","at 575/600 V rated value":"25 hp","Relative Humidity Minimum":"10 %","Of Main Circuit Rated Value":"6 kV","at AC-3 rated value maximum":"690 V","at AC in hot operating state":"6.3 W","at AC-2 at 400 V rated value":"15 kW","at AC-3e rated value maximum":"690 V","at AC-4 at 400 V rated value":"22 A","safety-related switching OFF":"Yes","Substance Prohibitance (Date)":"10/01/2009","Design Of The Surge Suppressor":"with varistor","Of Auxiliary Circuit Rated Value":"6 kV","at AC-5a up to 690 V rated value":"44 A","at AC-5b up to 400 V rated value":"26.5 A","For Auxiliary And Control Circuit":"spring-loaded terminals","Function Module For Communication":"No","With Type Of Assignment 2 Required":"gG: 50A (690V,100kA), aM: 25A (690V, 100kA), BS88: 50A (415V, 80kA)","Without Load Current Share Typical":"4.5 W","closing power of magnet coil at DC":"4.5 W","holding power of magnet coil at DC":"4.5 W","At Contactor For Auxiliary Contacts":"Spring-type terminals","With Type Of Coordination 1 Required":"gG: 125A (690V,100kA), aM: 50A (690V,100kA), BS88: 125A (415V,80kA)","operational current at AC-12 maximum":"10 A","at AC in hot operating state per pole":"2.3 W","for AWG cables for auxiliary contacts":"2x (20 ... 14)","number of NO contacts for main contacts":"3","reference code according to IEC 81346-2":"Q","Finely Stranded With Core End Processing":"2x (0.5 ... 1.5 mm²)","Number Of Poles For Main Current Circuit":"3","Contact Reliability Of Auxiliary Contacts":"1 faulty switching per 100 million (17 V, 1 mA)","mirror contact according to IEC 60947-4-1":"Yes","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 %","Type Of Voltage Of The Control Supply Voltage":"DC","Limited To 1 S Switching At Zero Current Maximum":"499 A; Use minimum cross-section acc. to AC-1 rated value","Limited To 5 S Switching At Zero Current Maximum":"341 A; Use minimum cross-section acc. to AC-1 rated value","Limited To 10 S Switching At Zero Current Maximum":"260 A; Use minimum cross-section acc. to AC-1 rated value","Limited To 30 S Switching At Zero Current Maximum":"199 A; Use minimum cross-section acc. to AC-1 rated value","Limited To 60 S Switching At Zero Current Maximum":"162 A; Use minimum cross-section acc. to AC-1 rated value","contact rating of auxiliary contacts according to UL":"A600 / P600","Of Main Circuit With Degree Of Pollution 3 Rated Value":"690 V","Installation Altitude At Height Above Sea Level Maximum":"2 000 m","Of The Contactor With Added Auxiliary Switch Block Typical":"10 000 000","Of Auxiliary Circuit With Degree Of Pollution 3 Rated Value":"690 V","For Short-Circuit Protection Of The Auxiliary Switch Required":"gG: 10 A (500 V, 1 kA)","minimum cross-section in main circuit at maximum AC-1 rated value":"10 mm²","number of NC contacts for auxiliary contacts instantaneous contact":"1","number of NO contacts for auxiliary contacts instantaneous contact":"1","Of The Contactor With Added Electronically Optimized Auxiliary Switch Block Typical":"5 000 000"}},"commercial":{"minOrderQty":null,"leadTime":null,"referencePrice":null,"priceTiers":null},"links":{"datasheetUrl":null,"sourceUrl":"https://support.industry.siemens.com/webbackend/api/ProductSupport/TechnicalData?language=en&region=cn&productId=535898&mlfb=3RT2027-2KA40","alternativesUrl":"https://aoctrl.com/api/mcp/products/3RT2027-2KA40/alternatives.json"},"ai":{"faq":[{"question":"How do I get current pricing and availability for 3RT2027-2KA40?","answer":"Submit an RFQ through this listing. Availability and current pricing are confirmed at quote time through our independent distribution channels."},{"question":"What is the depth of 3RT2027-2KA40?","answer":"The depth is 107 mm."},{"question":"What wire sizes does 3RT2027-2KA40 accept?","answer":"Solid or stranded conductors from 1 to 10 mm², and dual-wire 2x (0.5 … 2.5 mm²)."},{"question":"Will 3RT2027-2KA40 drop into a panel specified around 3RT2036-1AC20-ZX95?","answer":"Not directly — the 3RT2027-2KA40 is a size S0 coupling contactor with a 24 VDC coil and spring terminals, while the 3RT2036-1AC20-ZX95 is a different frame size and coil voltage. Panel fit and wiring would need to be re-evaluated."},{"question":"What compliance documentation is available for 3RT2027-2KA40?","answer":"As a Siemens SIRIUS product, it carries CE marking and is manufactured under IEC/EN 60947-4-1. RoHS and REACH declarations are available from Siemens on request."},{"question":"What is the difference between 3RT2027-2KA40 and 3RT2015-1BW42?","answer":"The 3RT2015-1BW42 is a smaller-frame contactor (size S00) with a 24 VDC coil and screw terminals, while the 3RT2027-2KA40 is size S0 with spring-type terminals and higher DC current ratings — 10 A vs 2 A at 24 VDC."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"matrix-langgraph","citationUrl":"https://aoctrl.com/siemens/3RT2027-2KA40","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/3RT2027-2KA40 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}}