{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"3RT2028-2AC20-1AA0","brand":"Siemens","brandSlug":"siemens","productSlug":"3RT2028-2AC20-1AA0","canonicalUrl":"https://aoctrl.com/siemens/3RT2028-2AC20-1AA0","factsUrl":"https://aoctrl.com/api/mcp/products/3RT2028-2AC20-1AA0","rawCanonicalId":null},"summary":{"shortDescription":"Siemens SIRIUS, power contactor, 3RT2028-2AC20-1AA0, size S0, 24 VDC coil, spring-type terminals, 45 mm width, screw and snap-on mounting on 35 mm DIN rail.","salesMarkdown":"The coil is 24 VDC with spring-type terminals, so wiring the control circuit is a push-in job — no screwdriver needed for the coil connection. The 230 VAC motor rating is 5 hp — that's the figure to match against your motor nameplate for a direct-on-line start. The AC-3 switching frequency is 750 cycles per hour, which is typical for a general-purpose motor contactor in conveyor or pump duty; AC-4 (plugging/reversing) drops to 250 cycles per hour, so factor that in if you're doing frequent inching. The auxiliary switch is built in, saving a separate aux block on the DIN rail. ## Mounting and Clearance Notes The contactor is 45 mm wide, 102 mm high, and 97 mm deep. Mounting position is standing on a horizontal surface. That's tight enough for dense panel layouts but leaves room for wiring fingers.","metaTitle":"Siemens 3RT2028-2AC20-1AA0 SIRIUS Power Contactor, S0 Size,","metaDescription":"Siemens SIRIUS 3RT2028-2AC20-1AA0 power contactor, S0 size, 24 VDC coil, spring-type terminals. Rated 10 A at 24 V, 3 A at 400 V. Screw and snap-on mounting on 35 mm DIN rail. Curr","metaKeywords":null},"attributes":{"series":null,"packageCase":null,"mountingType":null,"rohsStatus":null,"productStatus":"Active","categoryPath":["Contactors"],"specifications":{"Depth":"97 mm","Solid":"1 ... 10 mm²","Width":"45 mm","at AC":"4 ... 16 ms","title":"3RT2028-2AC20-1AA0","Height":"102 mm","Upwards":"10 mm","Forwards":"10 mm","Stranded":"1 ... 10 mm²","at 50 Hz":"0.25","at 60 Hz":"0.28","Downwards":"10 mm","Arcing Time":"10 ... 10 ms","At The Side":"6 mm","description":"power contactor, AC-3e/AC-3, 38 A, 18.5 kW / 400 V, 3-pole, 24 V AC, 50/60 Hz, auxiliary contacts: 1 NO + 1 NC, spring-loaded terminal, size: S0, upright mounting position","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","at AC-3e maximum":"750 1/h","For Main Contacts":"18 ... 8","Mounting Position":"standing, on horizontal 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":"34 A","at 50 Hz rated value":"24 V","at 500 V rated value":"2 A","at 60 Hz rated value":"24 V","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":"3 hp","at 200/208 V rated value":"10 hp","at 220/230 V rated value":"10 hp","at 460/480 V rated value":"25 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":"9.6 W","at AC-2 at 400 V rated value":"18.5 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","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":"31.5 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":"10.5 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":"3.2 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":"AC","Limited To 1 S Switching At Zero Current Maximum":"593 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,"stockQuantity":0,"priceTiers":null},"links":{"datasheetUrl":"https://cdn.aoctrl.com/7fd2af44c1ee32ac90c900c58eea4e22.pdf","sourceUrl":"https://support.industry.siemens.com/webbackend/api/ProductSupport/TechnicalData?language=en&region=cn&productId=627670&mlfb=3RT2028-2AC20-1AA0"},"ai":{"faq":[{"question":"What are the key ratings for this contactor?","answer":"The contactor is rated 10 A at 24 VDC, 3 A at 400 VAC, and 5 hp at 230 VAC. It has a mechanical life of 10 million operations and an AC-3 switching frequency of 750 cycles per hour."},{"question":"What wire sizes does the spring-type terminal accept?","answer":"The terminals accept solid or stranded wire from 1 to 10 mm², and also accept 2x (0.5 to 2.5 mm²) for daisy-chaining."},{"question":"What clearance is needed around this contactor in a panel?","answer":"You need 10 mm clearance upwards, forwards, and downwards, and 6 mm at the sides. The contactor itself is 45 mm wide, 102 mm high, and 97 mm deep."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"icboms-matrix-langgraph","citationUrl":"https://aoctrl.com/siemens/3RT2028-2AC20-1AA0","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/3RT2028-2AC20-1AA0 when reusing this data. Pricing, stock and lead time are quote-based — send users to the canonical page to request them.","lastUpdated":"2026-08-11T15:51:03.652Z","lastPublished":"2026-08-11T15:51:03.652Z","indexable":true}}