{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"3RT2028-1AC20-0JA0","brand":"Siemens","brandSlug":"siemens","productSlug":"3RT2028-1AC20-0JA0","canonicalUrl":"https://aoctrl.com/siemens/3RT2028-1AC20-0JA0","factsUrl":"https://aoctrl.com/api/mcp/products/3RT2028-1AC20-0JA0","rawCanonicalId":null},"summary":{"shortDescription":"Siemens SIRIUS S0 power contactor, 3RT2028-1AC20-0JA0, 45 mm width, screw-type coil terminals, auxiliary switch, screw and snap-on DIN rail mount.","salesMarkdown":"The contactor carries a mechanical endurance of 10 million operating cycles typical. The main contacts are configured as 16... 8 (likely NO/NC count). Switching frequency varies by duty: at AC-1 (resistive) it handles up to 1000 operations per hour, while AC-3 (motor starting) and AC-2 (slip-ring motor) are both rated at 750 ops/h. For AC-4 (plugging/inching) it drops to 250 ops/h — that's the number to check if your application involves frequent reversing or jogging. The auxiliary switch is included, rated at 24 V / 10 A through 230 V / 0.3 A for the contact side — enough for PLC input or relay coil feedback without an interposing relay in most 24 VDC control circuits. Side clearance to adjacent devices is 6 mm; vertical (up/down/forward) clearance is 10 mm. Wire range: solid or stranded 1 … 10 mm² for main power connections, with a separate specification for auxiliary circuits: 2x (0.5 … 1.5 mm²) or 2x (0.75 … 2.5 mm²). The coil terminals are screw-type, so expect a screwdriver for termination — no spring-cage on this variant. ## Environmental and electrical margins Coil holding power is 0.25 VA at 50 Hz and 0.28 VA at 60 Hz — negligible for control transformer sizing. Operating time at AC is 4 … 16 ms; arcing time is 10 … 10 ms.","metaTitle":"Siemens 3RT2028-1AC20-0JA0 SIRIUS S0 Power Contactor, 45 mm,","metaDescription":"Siemens SIRIUS 3RT2028-1AC20-0JA0 power contactor, size S0, 45 mm width, screw-type coil terminals, auxiliary switch included. Current production. Sourced to order against RFQ.","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":"3RT2028-1AC20-0JA0","Height":"85 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":"CONTACTOR, AC-3, 18.5KW/400V, 1NO+1NC, AC 24V 50/60HZ, 3-POLE, SZ S0 SCREW TERMINAL","During Storage":"-55 ... +80 °C","Of Magnet Coil":"Screw-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 ... +50 °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":"16 ... 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 ... 1.5 mm²), 2x (0.75 ... 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":"screw-type 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","Safety-Related Switching On":"Yes","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":"screw-type 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":"Screw-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 ... 16), 2x (18 ... 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), 2x (0.75 ... 2.5 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 %","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/056cd86fbfc3a229c3ffdc8e98410f0e.pdf","sourceUrl":"https://support.industry.siemens.com/webbackend/api/ProductSupport/TechnicalData?language=en&region=cn&productId=77990&mlfb=3RT2028-1AC20-0JA0"},"ai":{"faq":[{"question":"What wire sizes does this contactor accept?","answer":"Main power connections accept solid or stranded 1 … 10 mm². Auxiliary circuits accept 2x (0.5 … 1.5 mm²) or 2x (0.75 … 2.5 mm²)."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"icboms-matrix-langgraph","citationUrl":"https://aoctrl.com/siemens/3RT2028-1AC20-0JA0","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/3RT2028-1AC20-0JA0 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}}