{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"3RT2028-1BG40","brand":"Siemens","brandSlug":"siemens","productSlug":"3RT2028-1BG40","canonicalUrl":"https://aoctrl.com/siemens/3RT2028-1BG40","factsUrl":"https://aoctrl.com/api/mcp/products/3RT2028-1BG40","rawCanonicalId":null},"summary":{"shortDescription":"Siemens SIRIUS S0 power contactor, 3RT2028-1BG40, 24 VDC coil, screw-type terminals, 45 mm width, 10 A rated current at 24 V, 107 mm depth.","salesMarkdown":"The S0 frame size (45 mm wide, 85 mm tall, 107 mm deep) is the standard building block for motor loads up to roughly 5.5 kW at 400 V in AC-3 duty. The main contactor is rated for 1 000 operations per hour in AC-1 (resistive) duty, 750/h in AC-2 and AC-3 (motor start/run), and 250/h in AC-4 (plugging/reversing). The AC-3e rating also sits at 750/h, matching the standard motor-switching tempo for conveyor, pump, and fan applications. The built-in auxiliary switch (1 N/O + 1 N/C, wired as 16-8 on the main contact block) carries 10 A at 24 VDC, 2 A at 48 VDC, 2 A at 60 VDC, 1 A at 110 VDC, 0.9 A at 125 VDC, 0.3 A at 220 VDC, and 3 A at 400 VAC. That DC curve matters if you are switching a PLC input or a DC brake coil — the 24 V rating is generous, but the drop-off above 60 V is steep. Arcing time is 10 ms, and the DC dropout delay (coil off to contacts open) is 15-18 ms. That is fast enough for most safety circuits but worth noting if you are coordinating with a downstream contactor that has a longer dropout.","metaTitle":"Siemens 3RT2028-1BG40 SIRIUS S0 Power Contactor, 24 VDC Coil","metaDescription":"Siemens 3RT2028-1BG40 SIRIUS S0 power contactor, 24 VDC coil, screw terminals, 45 mm wide, 10 A rated current at 24 V. Active production, available to order. Quoted on request.","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":"125 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-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":"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":null,"sourceUrl":"https://support.industry.siemens.com/webbackend/api/ProductSupport/TechnicalData?language=en&region=cn&productId=433972&mlfb=3RT2028-1BG40","alternativesUrl":"https://aoctrl.com/api/mcp/products/3RT2028-1BG40/alternatives.json"},"ai":{"faq":[{"question":"Where can I buy 3RT2028-1BG40 and how do I get a price?","answer":"This part is sourced and quoted to order against an RFQ through independent distribution. Availability and current pricing are confirmed at quote time."},{"question":"What is 3RT2028-1BG40's listed depth?","answer":"The depth is 107 mm."},{"question":"What wire sizes does the 3RT2028-1BG40 accept?","answer":"The main circuit accepts solid or stranded conductors from 1 to 10 mm². The auxiliary terminals accept 2x (0.5 to 1.5 mm²) or 2x (0.75 to 2.5 mm²)."},{"question":"Will 3RT2028-1BG40 drop into a panel specified around 3RT2036-1AC20-ZX95 without rewiring?","answer":"Both are SIRIUS S0 frame contactors with the same 45 mm width, 85 mm height, and 107 mm depth, and both mount on 35 mm DIN rail. The 3RT2028-1BG40 uses a 24 VDC coil with screw terminals, while the 3RT2036-1AC20-ZX95 carries a different coil voltage and may include special markings (ZX95). The physical footprint is identical, so a direct swap is possible if the coil voltage matches the circuit."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"matrix-langgraph","citationUrl":"https://aoctrl.com/siemens/3RT2028-1BG40","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/3RT2028-1BG40 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}}