{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"3RT2027-2BF40","brand":"Siemens","brandSlug":"siemens","productSlug":"3RT2027-2BF40","canonicalUrl":"https://aoctrl.com/siemens/3RT2027-2BF40","factsUrl":"https://aoctrl.com/api/mcp/products/3RT2027-2BF40","rawCanonicalId":null},"summary":{"shortDescription":"Siemens SIRIUS power contactor, 3RT2027-2BF40, S0 frame size, 110 VAC coil, spring-type terminals, screw and snap-on 35 mm DIN rail mounting.","salesMarkdown":"It's a current-production part, so you're not hunting NOS or surplus for this one. The 110 VAC coil is rated at 0.8 times the rated value for pickup and 1.1 times for the full-scale value, meaning it'll pull in reliably on a sagging line but won't cook if the transformer runs a touch high. The spring-type terminals on the magnet coil and main contacts accept solid or stranded wire from 1 to 10 mm², or 2x (0.5 to 2.5 mm²) for daisy-chaining control wiring. The S0 footprint is 45 mm wide, 102 mm tall, 107 mm deep — it'll fit a standard 8-inch deep enclosure with room for the gland plate. That's tight enough to pack contactors side-by-side in a multi-motor starter bucket without cooking each other. ## Switching capability and life Main contacts rated AC-1 at 18 A, AC-3 at 8 A — that's the motor-switching number that matters for a 5 hp, 230 V single-phase or a small three-phase motor. The 10 million mechanical operations typical life means it'll outlast the machine it's in, assuming you're not cycling it every 10 seconds. Switching frequency: 1,000 ops/hour at AC-1, 750 at AC-2 and AC-3, 250 at AC-4. If you're jogging or inching a load, stay under 250 cycles per hour or the arc chute will cook. Auxiliary switch is included, rated at 10 A at 24 V, 2 A at 48/60 V, 1 A at 110 V, 0.9 A at 125 V, 0.3 A at 220 V, and 3 A at 400 V. That covers most PLC input and relay coil loads without an interposing relay. ## Environmental tolerance That's fine for a non-condensing panel next to a hot motor or in an unheated warehouse. The arcing time is a tight 10 to 10 ms — consistent, which helps with contactor life on inductive loads. Pickup and dropout timing on DC is 15 to 18 ms — snappy enough for most sequencing, but if you're coordinating with a safety relay, account for that window in your timing budget.","metaTitle":"Siemens 3RT2027-2BF40 SIRIUS Power Contactor, 110 VAC Coil,","metaDescription":"Siemens 3RT2027-2BF40 SIRIUS power contactor, S0 frame, 110 VAC coil, spring-type terminals. Rated for motor switching up to 5 hp at 230 V. Current production. Sourced to order via","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":"15 ... 18 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":"110 V","Initial Value":"0.8","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":"Yes","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":"1.1","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":"Power 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-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","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":"5.9 W","closing power of magnet coil at DC":"5.9 W","holding power of magnet coil at DC":"5.9 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":"https://cdn.aoctrl.com/6aff05bcd1e548f4bfa37655acb263c8.pdf","sourceUrl":"https://support.industry.siemens.com/webbackend/api/ProductSupport/TechnicalData?language=en&region=cn&productId=501760&mlfb=3RT2027-2BF40","alternativesUrl":"https://aoctrl.com/api/mcp/products/3RT2027-2BF40/alternatives.json"},"ai":{"faq":[{"question":"What are the key dimensions?","answer":"Width 45 mm, height 102 mm, depth 107 mm. Clearances: 10 mm up/down/forward, 6 mm sideways."},{"question":"What wire sizes does the spring terminal accept?","answer":"Solid or stranded wire from 1 to 10 mm² for main contacts, and 2x (0.5 to 2.5 mm²) for daisy-chaining auxiliary wiring."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"matrix-langgraph","citationUrl":"https://aoctrl.com/siemens/3RT2027-2BF40","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/3RT2027-2BF40 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}}