{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"3RT2028-2AG20","brand":"Siemens","brandSlug":"siemens","productSlug":"3RT2028-2AG20","canonicalUrl":"https://aoctrl.com/siemens/3RT2028-2AG20","factsUrl":"https://aoctrl.com/api/mcp/products/3RT2028-2AG20","rawCanonicalId":null},"summary":{"shortDescription":"Siemens SIRIUS 3RT2028-2AG20 power contactor, size S0, 24 VDC coil, spring-type terminals, 45 mm width, current production.","salesMarkdown":"The 3RT2028-2AG20: The AC-3 switching frequency is rated at 750 operations per hour maximum. That's the standard motor-switching duty cycle — running a pump or conveyor at that rate is fine, but if you're jogging or inching a load, you'll need to stay under the AC-4 limit of 250 ops/h to avoid overheating the contacts. That's the contactor body itself — the electrical life will be lower depending on the load and switching frequency, but the mechanical endurance means the frame and armature aren't the weak link in a high-cycle application. That's the inrush to pull the armature in; holding current will be lower. Make sure your 24 VDC supply can deliver that peak without droop, especially if you're switching multiple contactors simultaneously. That's tighter than some contactors, so you can pack them in a bit more on the rail. That helps when you're fitting it into an odd-angle sub-panel or a tight enclosure corner. Spring-type terminals on the coil — no screw tightening needed, just push in the ferrule. Main contacts accept solid or stranded wire from 1 to 10 mm², and fine-stranded (2x 0.5 to 2.5 mm²). That covers most motor leads up to about 4 kW at 400 V. Torque for main contacts is 18 to 8 Nm — that's a wide range, so check the specific terminal marking before tightening. The storage range is wide enough for long-term spares in a cold storeroom.","metaTitle":"Siemens 3RT2028-2AG20 SIRIUS S0 Power Contactor, 24 VDC Coil","metaDescription":"Siemens SIRIUS 3RT2028-2AG20 power contactor, size S0, 24 VDC coil, spring-type terminals. Rated for AC-3 switching up to 750 cycles/h. Current production status. Sourced to order.","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":"3RT2028-2AG20","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, 110 V AC, 50/60 Hz, auxiliary contacts: 1 NO + 1 NC, spring-loaded terminal, size: S0","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":"+/-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":"34 A","at 50 Hz rated value":"110 V","at 500 V rated value":"2 A","at 60 Hz rated value":"110 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-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/f555ec5f9857d0a7737f33d82822ec0f.pdf","sourceUrl":"https://support.industry.siemens.com/webbackend/api/ProductSupport/TechnicalData?language=en&region=cn&productId=504396&mlfb=3RT2028-2AG20"},"ai":{"faq":[{"question":"What are the key dimensions for panel layout?","answer":"Width is 45 mm, height 102 mm, depth 97 mm. Minimum clearances: 10 mm up/down/forward, 6 mm at the sides."},{"question":"What wire sizes does the spring terminal accept?","answer":"Solid or stranded wire from 1 to 10 mm², and fine-stranded 2x 0.5 to 2.5 mm². The coil terminal is spring-type — no screw needed."},{"question":"What is the maximum switching frequency for motor loads?","answer":"AC-3 (motor starting) is rated at 750 operations per hour maximum. For AC-4 (plugging/reversing), the limit is 250 ops/h."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"icboms-matrix-langgraph","citationUrl":"https://aoctrl.com/siemens/3RT2028-2AG20","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/3RT2028-2AG20 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}}