{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"3RT2028-2XB40-0LA2","brand":"Siemens","brandSlug":"siemens","productSlug":"3RT2028-2XB40-0LA2","canonicalUrl":"https://aoctrl.com/siemens/3RT2028-2XB40-0LA2","factsUrl":"https://aoctrl.com/api/mcp/products/3RT2028-2XB40-0LA2","rawCanonicalId":null},"summary":{"shortDescription":"Siemens SIRIUS 3RT2028-2XB40-0LA2 power contactor, Size S0, 24 V DC coil, spring-type terminals, 45 mm width, screw and snap-on DIN rail mounting.","salesMarkdown":"The 3RT2028-2XB40-0LA2: The 24 V DC coil with spring-type terminals eliminates the need for screwdriver torque control on the coil wiring — the spring clamp holds the conductor under constant pressure, resistant to vibration loosening. Rated for 5 hp at 230 V motor duty, this contactor handles typical pump, fan, and conveyor applications within the S0 frame's current envelope. ## Coil circuit and auxiliary contact ratings Dropout time at DC is 30 to 50 ms, which matters for sequencing logic where the contactor must release before a downstream device engages. These are the make/break capacities for the auxiliary contacts — the PLC input or relay it drives must be rated to handle the switched current at the applied voltage. ## Wiring and panel integration The spring-type terminals on both coil and main circuits mean no screw-torque verification — strip, insert, and the clamp engages. ## Switching frequency and thermal limits Maximum switching rate is 750 operations per hour in AC-1, AC-2, AC-3, and AC-3e duty, dropping to 250 ops/h in AC-4 (plugging/inching). For a conveyor running at 30 starts per hour, this is well within margin; for a rapid-cycling application like a press control, the AC-4 limit governs the duty cycle.","metaTitle":"Siemens 3RT2028-2XB40-0LA2 SIRIUS Contactor, 24 V DC","metaDescription":"Siemens 3RT2028-2XB40-0LA2 SIRIUS power contactor, 24 V DC coil, Size S0 frame, spring-type terminals, 45 mm wide. Current production — quoted to order.","metaKeywords":null},"attributes":{"series":null,"packageCase":null,"mountingType":null,"rohsStatus":null,"productStatus":"Active","categoryPath":["Contactors"],"specifications":{"Depth":"107 mm","Solid":"2x (1 ... 10 mm²)","Width":"45 mm","at DC":"30 ... 50 ms","title":"3RT2028-2XB40-0LA2","Height":"102 mm","Upwards":"10 mm","Forwards":"10 mm","Downwards":"10 mm","Arcing Time":"10 ... 10 ms","At The Side":"6 mm","Rated Value":"24 V","description":"traction contactor, AC-3e/AC-3, 38 A, 18.5 kW / 400 V, 3-pole, 24 V DC, 0.7-1.25* Us, electronic drive, with integrated varistor, auxiliary contacts: 1 NO + 1 NC, spring-loaded terminal, size: S0","Initial Value":"0.7","During Storage":"-55 ... +80 °C","Of Magnet Coil":"Spring-type terminals","Type Of Voltage":"DC","at AC-1 maximum":"750 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":"-40 ... +70 °C","Fastening Method":"screw and snap-on mounting onto 35 mm DIN rail according to DIN EN 60715","Full-Scale Value":"1.25","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","Inrush Current Peak":"3 A","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","Design Of The Product":"With extended operating range","Instantaneous Contact":"1","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","at AC-2 at AC-3e maximum":"750 1/h","Locked-Rotor Current Peak":"0.52 A","Relative Humidity Minimum":"10 %","Holding Current Mean Value":"45 mA","at maximum Ith rated value":"10 mm²","Of Main Circuit Rated Value":"6 kV","at AC-3 rated value maximum":"690 V","at maximum AC-1 rated value":"10 mm²","at AC in hot operating state":"11.4 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","Substance Prohibitance (Date)":"10/01/2009","Design Of The Surge Suppressor":"with varistor","Duration Of Inrush Current Peak":"30 µs","Locked-Rotor Current Mean Value":"0.3 A","Duration Of Locked-Rotor Current":"180 ms","Of Auxiliary Circuit Rated Value":"6 kV","For Auxiliary And Control Circuit":"spring-loaded terminals","Function Module For Communication":"No","Product Function Bus 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":"0.8 W","closing power of magnet coil at DC":"6.7 W","holding power of magnet coil at DC":"1.4 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":"3.8 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","Product Function Short Circuit Protection":"No","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 %","number of NC contacts for auxiliary contacts":"1","number of NO contacts for auxiliary contacts":"1","Type Of Voltage Of The Control Supply Voltage":"DC","up to 40 °C according to IEC 60077 rated value":"50 A","up to 70 °C according to IEC 60077 rated value":"38 A","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 / Q600","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)","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/7446a26f4c5049c580c16786cdd4fa9f.pdf","sourceUrl":"https://support.industry.siemens.com/webbackend/api/ProductSupport/TechnicalData?language=en&region=cn&productId=52621&mlfb=3RT2028-2XB40-0LA2"},"ai":{"faq":[{"question":"What wire sizes does the 3RT2028-2XB40-0LA2 accept on the main contacts?","answer":"The coil terminals use the same spring-type technology and accept the same wire ranges."},{"question":"What is the switching frequency for this contactor in AC-3 duty?","answer":"Maximum 750 operations per hour in AC-3 and AC-3e duty. For AC-4 (plugging/inching) the rate drops to 250 ops/h."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"icboms-matrix-langgraph","citationUrl":"https://aoctrl.com/siemens/3RT2028-2XB40-0LA2","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/3RT2028-2XB40-0LA2 when reusing this data. Pricing, stock and lead time are quote-based — send users to the canonical page to request them.","lastUpdated":"2026-07-22T19:47:38.189Z","lastPublished":"2026-07-22T19:47:38.189Z","indexable":true}}