{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"3RT1025-1BD40","brand":"Siemens","brandSlug":"siemens","productSlug":"3RT1025-1BD40","canonicalUrl":"https://aoctrl.com/siemens/3RT1025-1BD40","factsUrl":"https://aoctrl.com/api/mcp/products/3RT1025-1BD40","rawCanonicalId":null},"summary":{"shortDescription":"Siemens SIRIUS 3RT1025-1BD40 power contactor, Size S0, 45 mm width, screw-type terminals, 7.5 kW at AC-2 400 V, 11 kW at 690 V, 10 A at AC-12, 24 V DC coil.","salesMarkdown":"The 45 mm width and 85 mm height keep the footprint compact for dense enclosures. Rated for AC-2 duty at 7.5 kW on 400 V and 11 kW on 690 V, this contactor handles slip-ring motor starting and reversing loads. For resistive loads, the AC-12 rating at 10 A defines the maximum continuous current for non-inductive circuits like heater banks. DC switching capability is specified across four voltage levels: 10 A at 24 V, 2 A at 60 V, 1 A at 110 V, and 0.3 A at 220 V. These are the make/break capacities for DC loads where arc extinction is harder than AC — relevant for brake coils, DC valve solenoids, or battery-backed control circuits. The 11 kW at 690 V extends the same duty to higher-voltage three-phase systems common in heavy industrial plants. The AC-4 current of 15.5 A at 400 V sets the limit for reversing or jogging applications — expect shorter electrical life if you cycle near this rating frequently. This simplifies the control transformer sizing: budget 5.4 W steady-state per contactor. These values determine the upstream fuse selection in your distribution board and affect the SCCR rating of the entire panel assembly. ## Mounting and Wiring Integration The main circuit uses screw-type terminals accepting 2x (0.5...1.5 mm²), 2x (0.75...2.5 mm²), max 2x (0.75...4 mm²) for solid conductors, or 2x (1...2.5 mm²), 2x (2.5...6 mm²), max 2x 10 mm² for stranded. AWG equivalents are 2x (16...12), 2x (14...10), 1x 8. This range covers most motor feeder cables up to 4 mm² solid or 6 mm² stranded without needing terminal adapters. Front protection is IP20 — safe against finger contact when mounted in a panel. The terminal area itself is IP00, meaning the connection points are not touch-safe until the panel door is closed. The maximum operating altitude is 2000 m without derating; above that, dielectric strength and air clearance must be reviewed per IEC 60947-1. For a buyer filling a BOM line, the key fit confirmations are: Size S0 footprint (45 mm wide), AC-2 motor power at your system voltage, and the 24 V DC coil (the -1BD40 suffix indicates the coil voltage). The mechanical life of 10 million operations means this contactor will outlast most machinery overhauls in normal cycling service.","metaTitle":"Siemens SIRIUS 3RT1025-1BD40 Power Contactor, Size S0, 45 mm","metaDescription":"Siemens SIRIUS 3RT1025-1BD40 power contactor, Size S0, 45 mm width, 7.5 kW at AC-2 400 V, 11 kW at 690 V. Screw terminals, DIN-rail mount. Current lifecycle stage.","metaKeywords":null},"attributes":{"series":null,"packageCase":null,"mountingType":null,"rohsStatus":null,"productStatus":null,"categoryPath":["Contactors"],"specifications":{"Depth":"101 mm","Solid":"2x (0.5 ... 1.5 mm²), 2x (0.75 ... 2.5 mm²), max. 2x (0.75 ... 4 mm²)","Width":"45 mm","Height":"85 mm","Maximum":"2 000 m","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 230 V rated value":"6 A","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 AC-2 at 400 V rated value":"7.5 kW","at AC-4 at 400 V rated value":"15.5 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","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 NC contacts for main contacts":"0","Number of NO contacts for main contacts":"3","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","at AWG conductors for auxiliary contacts":"2x (20 ... 16), 2x (18 ... 14), 1x 12","Contact reliability of auxiliary contacts":"1 faulty switching per 100 million (17 V, 1 mA)","For Auxiliary And Control Current Circuit":"screw-type terminals","at ambient temperature 40 °C rated value":"40 A","Type of voltage of the control supply voltage":"DC","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"}},"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=171384&mlfb=3RT1025-1BD40","alternativesUrl":"https://aoctrl.com/api/mcp/products/3RT1025-1BD40/alternatives.json"},"ai":{"faq":[{"question":"What is the closest functional alternative to the 3RT1025-1BD40?","answer":"The 3RT1023-1AL20 is a Size S0 peer but uses a different coil voltage (230 V AC, 50 Hz). The 3RT1025-1BD40 has a 24 V DC coil. The 3RT1015-1BB42 and 3RT1016-2AP02 are smaller frame sizes (S00) with lower current ratings — they are not drop-in replacements without rewiring the panel and checking the motor load."},{"question":"What wire sizes does the 3RT1025-1BD40 accept?","answer":"Solid conductors: 2x (0.5...1.5 mm²), 2x (0.75...2.5 mm²), max 2x (0.75...4 mm²). Stranded: 2x (1...2.5 mm²), 2x (2.5...6 mm²), max 2x 10 mm². AWG equivalents: 2x (16...12), 2x (14...10), 1x 8."},{"question":"Will the 3RT1025-1BD40 drop into a panel designed for a 3RT1023-1AL20?","answer":"The physical footprint (Size S0, 45 mm wide) is identical, so mechanical fit is the same. The difference is the coil: the 3RT1025-1BD40 requires 24 V DC, while the 3RT1023-1AL20 uses 230 V AC. The control transformer and wiring must be changed to supply 24 V DC instead of 230 V AC."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"matrix-langgraph","citationUrl":"https://aoctrl.com/siemens/3RT1025-1BD40","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/3RT1025-1BD40 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}}