{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"3RT2028-1BF40","brand":"Siemens","brandSlug":"siemens","productSlug":"3RT2028-1BF40","canonicalUrl":"https://aoctrl.com/siemens/3RT2028-1BF40","factsUrl":"https://aoctrl.com/api/mcp/products/3RT2028-1BF40","rawCanonicalId":null},"summary":{"shortDescription":"Siemens SIRIUS, power contactor, 3RT2028-1BF40, Size S0, 110 V AC coil, screw-type terminals, 45 mm width, snap-on DIN rail mounting.","salesMarkdown":"It mounts on a 35 mm DIN rail per DIN EN 60715 via screw or snap-on fastening, and the mounting position allows ±180° rotation on a vertical surface plus ±22.5° tilt forward and backward — useful when panel layout forces an unconventional orientation. ## Coil and switching ratings The coil is rated 110 V AC with screw-type terminals. For DC switching, the contactor handles 10 A at 24 V, 2 A at 48 V, 2 A at 60 V, 1 A at 110 V, 0.9 A at 125 V, and 0.3 A at 220 V — so it covers control-circuit loads across common DC bus voltages. The arcing time sits at 10 ms, and the operate time at DC is 15–18 ms, which matters when coordinating with upstream protection or sequencing multiple contactors. ## Mechanical and electrical endurance Electrical switching frequency varies by duty: 1,000 ops/h at AC-1 (resistive), 750 ops/h at AC-2 and AC-3 (motor starting/running), and 250 ops/h at AC-4 (plugging/inching). The AC-3e rating also allows 750 ops/h. For a motor-switching application, the 750 ops/h ceiling means it handles frequent starts on a conveyor or pump without exceeding thermal limits. Auxiliary contacts use a smaller range: 2x (0.5–1.5 mm²) or 2x (0.75–2.5 mm²). The screw-type terminals are standard for panel wiring — no special tooling needed. No last-time-buy or phase-out notice applies — the lifecycle stage is current.","metaTitle":"Siemens 3RT2028-1BF40 SIRIUS Power Contactor, 110 V Coil, S0","metaDescription":"Siemens SIRIUS 3RT2028-1BF40 power contactor, Size S0, 110 V AC coil, screw terminals. Rated for AC-3 motor switching at 750 ops/h. Current lifecycle stage active. Sourced to order","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":"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":"110 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 DIN 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","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)","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":"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":"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/baa32e4e865b5e5a3d73c78ef71a33b2.pdf","sourceUrl":"https://support.industry.siemens.com/webbackend/api/ProductSupport/TechnicalData?language=en&region=cn&productId=482632&mlfb=3RT2028-1BF40","alternativesUrl":"https://aoctrl.com/api/mcp/products/3RT2028-1BF40/alternatives.json"},"ai":{"faq":[{"question":"How do I get current pricing and availability for 3RT2028-1BF40?","answer":"Pricing and availability are confirmed at quote time against an RFQ. Submit a request through the storefront for a current quote."},{"question":"What is 3RT2028-1BF40's listed depth?","answer":"The depth is 107 mm. Combined with the 45 mm width and 85 mm height, this defines the panel footprint for DIN-rail layout."},{"question":"What wire sizes does 3RT2028-1BF40 accept?","answer":"Main contacts accept solid or stranded wire from 1 to 10 mm². Auxiliary contacts accept 2x (0.5–1.5 mm²) or 2x (0.75–2.5 mm²)."},{"question":"Will 3RT2028-1BF40 drop into a panel specified around 3RT2015-1BW42?","answer":"Both are SIRIUS Size S0 contactors with the same 45 mm width and DIN-rail mounting, so the physical footprint is identical. Verify coil voltage — 3RT2028-1BF40 uses a 110 V AC coil — and terminal wiring range before substitution."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"matrix-langgraph","citationUrl":"https://aoctrl.com/siemens/3RT2028-1BF40","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/3RT2028-1BF40 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}}