{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"3RT1025-3BD40","brand":"Siemens","brandSlug":"siemens","productSlug":"3RT1025-3BD40","canonicalUrl":"https://aoctrl.com/siemens/3RT1025-3BD40","factsUrl":"https://aoctrl.com/api/mcp/products/3RT1025-3BD40","rawCanonicalId":null},"summary":{"shortDescription":"Siemens SIRIUS power contactor, size S0, 3-pole, 42 VDC coil, screw terminals, 7.5 kW at 400 V AC-3, 45 mm wide, IP20 front.","salesMarkdown":"It carries three normally-open main contacts and a 42 VDC coil that draws 5.4 W on both closing and holding — a single-wattage coil, so the control transformer sees a steady load. The 3RT1025-3BD40 is rated for motor switching in AC-3 duty (starting and disconnecting squirrel-cage motors under load). At 400 V it handles 7.5 kW; at 500 V, 10 kW; at 690 V, 11 kW. In AC-2 duty (slip-ring motors) at 400 V it also carries 7.5 kW. ## Panel fit and wiring constraints The contactor body is 45 mm wide, 85 mm tall, and 100 mm deep — a compact S0 footprint that leaves room for auxiliary contact blocks on the side (6 mm clearance needed). The screw-type main terminals accept 2x (0.25 to 2.5 mm²) solid, 2x (1 to 2.5 mm²) stranded, or up to 2x 10 mm² single-core. For AWG, that's 2x (16 to 12) solid or 2x (14 to 10) stranded, with a maximum single 8 AWG. The contactor itself has a mechanical life of 10 million operations typical — that's the unloaded switching endurance; electrical life depends on the load current and duty cycle.","metaTitle":"Siemens 3RT1025-3BD40 SIRIUS Power Contactor, 3-Pole, 42 VDC","metaDescription":"Siemens 3RT1025-3BD40 SIRIUS power contactor, size S0, 3 NO main contacts, 42 VDC coil, rated 7.5 kW at 400 V AC-3. Active production. Sourced to order.","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":"85 mm","At The Side":"6 mm","Rated Value":"42 V","On The Front":"IP20","Initial Value":"0.8","Mounting Type":"screw and snap-on mounting onto 35 mm standard mounting rail according to DIN EN 50022","Of The Terminal":"IP00","lifecycle_stage":"current","During Operation":"-25 ... +60 °C","Full-Scale Value":"1.1","Size Of Contactor":"S0","Product Brand Name":"SIRIUS","Degree Of Pollution":"3","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 400 V rated value":"7.5 kW","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 AC-2 at 400 V rated value":"7.5 kW","at AC-4 at 400 V rated value":"15.5 A","With Type Of Assignment 2 Required":"fuse gL/gG: 25 A","closing power of magnet coil at DC":"5.4 W","holding power of magnet coil at DC":"5.4 W","operating current at AC-12 maximum":"10 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 NC contacts for main contacts":"0","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","Contact Reliability Of Auxiliary Contacts":"1 faulty switching per 100 million (17 V, 1 mA)","For Auxiliary And Control Current Circuit":"spring-loaded terminals","at ambient temperature 40 °C rated value":"40 A","Finely Stranded Without Core End Processing":"2x (0.25 ... 2.5 mm²)","Type Of Voltage Of The Control Supply Voltage":"DC","operating current at AC-15 at 230 V rated value":"6 A","operating current at AC-15 at 400 V rated value":"3 A","Installation Altitude At Height Above Sea Level Maximum":"2 000 m","Of The Contactor With Added Auxiliary Switch Block Typical":"10 000 000","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","type of connectable conductor cross-sections at AWG conductors for auxiliary contacts":"2x (24 ... 14)"}},"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=34896&mlfb=3RT1025-3BD40","alternativesUrl":"https://aoctrl.com/api/mcp/products/3RT1025-3BD40/alternatives.json"},"ai":{"faq":[{"question":"How do I get current pricing and availability for 3RT1025-3BD40?","answer":"Submit an RFQ through this listing. The part is sourced to order via independent distribution; pricing and stock levels are confirmed at quote time."},{"question":"What is 3RT1025-3BD40's listed depth?","answer":"The depth is 100 mm, with a width of 45 mm and height of 85 mm — a compact S0 frame size."},{"question":"What compliance documentation does Siemens provide for 3RT1025-3BD40?","answer":"The part carries a reference code per DIN EN 81346-2 (Q for power switching equipment). Standard Siemens documentation includes the declaration of conformity for the Low Voltage Directive; specific RoHS and REACH declarations are available through the Siemens Industry Online Support portal."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"matrix-langgraph","citationUrl":"https://aoctrl.com/siemens/3RT1025-3BD40","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/3RT1025-3BD40 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}}