{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"3RT1025-1BF40","brand":"Siemens","brandSlug":"siemens","productSlug":"3RT1025-1BF40","canonicalUrl":"https://aoctrl.com/siemens/3RT1025-1BF40","factsUrl":"https://aoctrl.com/api/mcp/products/3RT1025-1BF40","rawCanonicalId":null},"summary":{"shortDescription":"Siemens SIRIUS power contactor, 3RT1025-1BF40, size S0, 3-pole NO main contacts, 110 VDC coil, screw-type terminals, 7.5 kW at 400 V AC-3, IP20 front.","salesMarkdown":"## SIRIUS S0 power contactor, 110 VDC coil It's rated for 7.5 kW motor switching at 400 V AC-3 duty, which covers the common 400 V three-phase induction motor range up to that power. The DC coil pulls 5.4 W on closing and holds at 5.4 W — no economizer circuit needed, but verify your DC supply can deliver the inrush without droop. That's the number that governs real motor duty. The AC-4 rating of 15.5 A at 400 V covers plugging and inching, which is harder on the contacts; if your application does frequent reversing or jogging, size on the AC-4 figure, not AC-3. This matters for selectivity studies — if you're protecting downstream devices, the 25 A limit constrains your fuse choice. That's standard for unsealed panels in factory floors, not for clean rooms or sealed enclosures without condensation management. The IP20 front / IP00 terminal rating means the front of the contactor is finger-safe, but the terminals are exposed — they need to be inside a panel or guarded. Not a standalone device for open mounting. ## Wiring and terminal details Main circuit terminals are screw-type, accepting solid wire: 2x (0.5 to 1.5 mm²), 2x (0.75 to 2.5 mm²), max 2x (0.75 to 4 mm²). Stranded: 2x (1 to 2.5 mm²), 2x (2.5 to 6 mm²), max 2x 10 mm². AWG equivalents: 2x (16 to 12), 2x (14 to 10), 1x 8. That covers most panel wiring up to 4 mm² solid or 10 mm² stranded — enough for the 25 A fuse coordination path.","metaTitle":"Siemens 3RT1025-1BF40 SIRIUS Power Contactor, 110 VDC Coil,","metaDescription":"Siemens SIRIUS 3RT1025-1BF40 power contactor, size S0, 3-pole NO, 110 VDC coil, 7.5 kW at 400 V AC-3. Screw terminals, DIN rail mount. Current lifecycle stage. Quoted to order.","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","At The Side":"6 mm","Rated Value":"110 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 (0.5 ... 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)","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","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 (20 ... 16), 2x (18 ... 14), 1x 12"}},"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=421501&mlfb=3RT1025-1BF40","alternativesUrl":"https://aoctrl.com/api/mcp/products/3RT1025-1BF40/alternatives.json"},"ai":{"faq":[{"question":"What is the 3RT1025-1BF40's depth?","answer":"The depth is 101 mm. Combined with the 45 mm width and 85 mm height, it fits the standard S0 contactor footprint for DIN-rail panels."},{"question":"What wire sizes does the 3RT1025-1BF40 accept?","answer":"Solid wire: 2x (0.5 to 1.5 mm²), 2x (0.75 to 2.5 mm²), max 2x (0.75 to 4 mm²). Stranded: 2x (1 to 2.5 mm²), 2x (2.5 to 6 mm²), max 2x 10 mm². AWG: 2x (16 to 12), 2x (14 to 10), 1x 8."},{"question":"Will 3RT1025-1BF40 drop into a panel specified for 3RT1023-1AL20 without rewiring?","answer":"Both are S0 frame size with the same 45 mm width and DIN-rail mounting, so the mechanical footprint matches. But the coil voltage differs — the 3RT1025-1BF40 uses 110 V DC, while the 3RT1023-1AL20 uses a different coil. Verify your control voltage matches before substitution."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"matrix-langgraph","citationUrl":"https://aoctrl.com/siemens/3RT1025-1BF40","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/3RT1025-1BF40 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}}