{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"3RT1025-3XB40-0LA2","brand":"Siemens","brandSlug":"siemens","productSlug":"3RT1025-3XB40-0LA2","canonicalUrl":"https://aoctrl.com/siemens/3RT1025-3XB40-0LA2","factsUrl":"https://aoctrl.com/api/mcp/products/3RT1025-3XB40-0LA2","rawCanonicalId":null},"summary":{"shortDescription":"Siemens SIRIUS 3RT1025-3XB40-0LA2 power contactor, size S0, 24 V DC coil, screw-type terminals, DIN rail mount, 45 mm width.","salesMarkdown":"The DC coil draws 10 A at 24 V inrush, holding at 0.7 A (the initial vs. full-scale values), so your 24 VDC power supply needs to handle that peak pull-in current. Drop-out is typically below 18 V — a standard curve for DC-operated contactors. AC motor ratings tell you what this contactor can handle: 3 hp at 230 V, 10 hp at 460/480 V, and 15 hp at 575/600 V. For IEC duty, it's rated 11 kW at 690 V. The AC-4 switching current at 400 V is 15.5 A — that's the reversing/plugging duty cycle, which is more demanding than AC-3. DC switching ratings are given at several voltages: 10 A at 24 V, 2 A at 60 V, 1 A at 110 V, and 0.3 A at 220 V. These are resistive load values — inductive DC loads will need derating or arc suppression. At 45 mm wide, 119 mm tall, and 100 mm deep, this S0 contactor occupies standard DIN-rail space. That's enough for airflow and wiring access in a typical enclosure. Screw terminals accept 2x (0.25–2.5 mm²) solid or stranded, and up to 2x 10 mm² for the main circuit. The rated impulse withstand voltage of 6 kV means this contactor is suitable for installation in circuits with overvoltage category III up to 400 V — typical for industrial motor branch circuits. The maximum operating altitude of 2,000 m limits installation to most standard industrial sites without derating. Mechanical life of 10 million cycles is typical for a contactor of this class. Electrical life will be lower depending on the switching load — AC-4 duty at 15.5 A will reduce it significantly compared to AC-1 resistive switching.","metaTitle":"Siemens 3RT1025-3XB40-0LA2 SIRIUS Power Contactor, S0, 24 V","metaDescription":"Siemens SIRIUS 3RT1025-3XB40-0LA2 power contactor, size S0, 24 V DC coil. AC motor ratings to 15 hp at 575/600 V. Screw terminals, DIN rail mount. Active production, sourced to ord","metaKeywords":null},"attributes":{"series":null,"packageCase":null,"mountingType":null,"rohsStatus":null,"productStatus":null,"categoryPath":["Contactors"],"specifications":{"Depth":"100 mm","Solid":"2x (0.25 ... 2.5 mm²)","Width":"45 mm","Height":"119 mm","Maximum":"2 000 m","Upwards":"10 mm","Forwards":"10 mm","Downwards":"10 mm","At The Side":"10 mm","Rated Value":"24 V","On The Front":"IP20","Initial Value":"0.7","Mounting type":"screw and snap-on mounting onto 35 mm standard mounting rail according to DIN EN 50022","Of The Terminal":"IP00","Type of voltage":"DC","lifecycle_stage":"current","Full-scale value":"1.25","Size of contactor":"S0","Product brand name":"SIRIUS","Product designation":"Power contactor","at 24 V rated value":"10 A","at 60 V rated value":"2 A","Of Contactor Typical":"10 000 000","at 110 V rated value":"1 A","at 220 V rated value":"0.3 A","at 230 V rated value":"3 hp","at 400 V rated value":"3 A","at 500 V rated value":"10 kW","at 690 V rated value":"11 kW","Instantaneous Contact":"0","Side-by-side mounting":"Yes","For Main Current Circuit":"screw-type terminals","Single Or Multi-Stranded":"2x (1 ... 2,5 mm²), 2x (2,5 ... 6 mm²), max. 2x 10 mm²","at 110/120 V rated value":"1 hp","at 200/208 V rated value":"5 hp","at 220/230 V rated value":"5 hp","at 460/480 V rated value":"10 hp","at 575/600 V rated value":"15 hp","Of Main Circuit Rated Value":"6 kV","at AC-4 at 400 V rated value":"15.5 A","Design of the surge suppressor":"with varistor","Of Auxiliary Circuit Rated Value":"6 kV","Function Module For Communication":"No","Closing power of magnet coil at DC":"6 W","Holding power of magnet coil at DC":"5.4 W","Operating current at AC-12 maximum":"10 A","Product function Bus communication":"No","With Type Of Assignment 2 Required":"fuse gL/gG: 25 A","at AWG conductors for main contacts":"2x (16 ... 12), 2x (14 ... 10), 1x 8","With Type Of Coordination 1 Required":"fuse gL/gG: 63 A","Reference code acc. to DIN EN 81346-2":"Q","Number of NO contacts for main contacts":"3","Finely Stranded With Core End Processing":"2x (0.25 ... 1.5 mm²)","Number of poles for main current circuit":"3","at AWG conductors for auxiliary contacts":"2x (24 ... 14)","Contact reliability of auxiliary contacts":"1 faulty switching per 100 million (17 V, 1 mA)","For Auxiliary And Control Current Circuit":"spring-loaded terminals","Product function Short circuit protection":"No","Finely Stranded Without Core End Processing":"2x (0.25 ... 2.5 mm²)","Number of NC contacts for auxiliary contacts":"2","Number of NO contacts for auxiliary contacts":"2","Type of voltage of the control supply voltage":"DC","Of Main Circuit With Degree Of Pollution 3 Rated Value":"690 V","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":"fuse gL/gG: 10 A","Of The Contactor With Added Electronics-Compatible 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=40199&mlfb=3RT1025-3XB40-0LA2","alternativesUrl":"https://aoctrl.com/api/mcp/products/3RT1025-3XB40-0LA2/alternatives.json"},"ai":{"faq":[{"question":"What is the closest functional alternative to this contactor?","answer":"The 3RT2024-2BB40 is a similar SIRIUS contactor but with a 24 V AC coil instead of DC. If your control circuit is 24 V DC, stick with the 3RT1025-3XB40-0LA2 — the AC coil version will not hold in on DC. The 3RT2026-1KB40 and 3RT2026-1FB44-3MA0 are different frame sizes or coil voltages, so they are not drop-in replacements without panel rework."},{"question":"What is the depth of this contactor?","answer":"The depth is 100 mm. With the required 10 mm forward clearance, the total depth needed in the enclosure is 110 mm from the DIN rail to the door or cover."},{"question":"What wire sizes does the screw terminal accept?","answer":"The main circuit terminals accept 2x (0.25–2.5 mm²) solid or stranded, 2x (1–2.5 mm²) and 2x (2.5–6 mm²), with a maximum of 2x 10 mm². The auxiliary terminals accept 2x (0.25–2.5 mm²). Use ferrules for stranded wire to ensure a reliable connection in the screw clamp."},{"question":"Will this contactor fit in a panel designed for a 3RT2024-2BB40?","answer":"Both are S0 frame size with the same 45 mm width and DIN-rail mounting, so the mechanical fit is identical. The critical difference is the coil: the 3RT1025-3XB40-0LA2 is 24 V DC, while the 3RT2024-2BB40 is 24 V AC. If your control transformer supplies AC, the DC coil will not work — you would need to add a rectifier or swap to the AC coil variant."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"matrix-langgraph","citationUrl":"https://aoctrl.com/siemens/3RT1025-3XB40-0LA2","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/3RT1025-3XB40-0LA2 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}}