{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"3RT2028-1BW40","brand":"Siemens","brandSlug":"siemens","productSlug":"3RT2028-1BW40","canonicalUrl":"https://aoctrl.com/siemens/3RT2028-1BW40","factsUrl":"https://aoctrl.com/api/mcp/products/3RT2028-1BW40","rawCanonicalId":null},"summary":{"shortDescription":"Siemens SIRIUS power contactor, 3RT2028-1BW40, S0 frame, 48 VDC coil, screw-type terminals, 45 mm width, 107 mm depth.","salesMarkdown":"The coil is rated 48 VDC, with a pickup threshold of 0.8 x rated value. The magnet coil termination is screw-type. For DC-13 duty (solenoid loads), the contactor switches 10 A at 24 V and 2 A at 48 V — that covers most DC brake coils and small solenoid valves in a 24 VDC control circuit. At 60 VDC the rating drops to 2 A, and at 110 VDC it's 1 A, so plan your load accordingly. The main contact rating for AC-1 allows up to 1,000 switching cycles per hour; for AC-3 it is 750 cycles per hour. The contactor accepts solid or stranded conductors from 1 to 10 mm² on the main contacts, and 2x (0.5 to 1.5 mm²) or 2x (0.75 to 2.5 mm²) on the auxiliary circuit. That covers most panel wiring from 14 AWG to 8 AWG. Dimensions: 45 mm wide, 85 mm high, 107 mm deep. ## Environmental limits","metaTitle":"Siemens 3RT2028-1BW40 SIRIUS Power Contactor, 48 VDC Coil, S","metaDescription":"Siemens 3RT2028-1BW40 SIRIUS power contactor, 48 VDC coil, S0 frame, 45 mm wide, screw terminals. Rated DC-13 switching at 24 V (10 A) and 48 V (2 A). Current lifecycle status. Sou","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 ... 17.5 ms","Height":"85 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":"48 V","Initial Value":"0.8","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 ... +60 °C","Fastening Method":"screw and snap-on mounting onto 35 mm standard mounting rail according to DIN EN 60715","Full-Scale Value":"1.1","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 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":"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","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","at AWG cables for main contacts":"2x (16 ... 12), 2x (14 ... 8)","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":"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":"Screw-type terminals","With Type Of Coordination 1 Required":"gG: 125A (690V,100kA), aM: 50A (690V,100kA), BS88: 125A (415V,80kA)","at AWG cables for auxiliary contacts":"2x (20 ... 16), 2x (18 ... 14)","operational current at AC-12 maximum":"10 A","at AC in hot operating state per pole":"3.2 W","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":"DC","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":"395 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":"186 A; Use minimum cross-section acc. to AC-1 rated value","Limited To 60 S Switching At Zero Current Maximum":"152 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/fcb53a17da53ab495b14cba8b1524de8.pdf","sourceUrl":"https://support.industry.siemens.com/webbackend/api/ProductSupport/TechnicalData?language=en&region=cn&productId=207744&mlfb=3RT2028-1BW40","alternativesUrl":"https://aoctrl.com/api/mcp/products/3RT2028-1BW40/alternatives.json"},"ai":{"faq":[{"question":"Will 3RT2028-1BW40 drop into a panel that was specified around 3RT2015-1BW42 without rewiring?","answer":"No — the 3RT2028-1BW40 uses the S0 frame (45 mm wide), while the 3RT2015-1BW42 uses the S00 frame (smaller). The DIN rail mounting is the same, but the terminal positions and clearance distances differ, so rewiring is required."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"matrix-langgraph","citationUrl":"https://aoctrl.com/siemens/3RT2028-1BW40","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/3RT2028-1BW40 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}}