{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"3RT1024-3KF40-1AA0","brand":"Siemens","brandSlug":"siemens","productSlug":"3RT1024-3KF40-1AA0","canonicalUrl":"https://aoctrl.com/siemens/3RT1024-3KF40-1AA0","factsUrl":"https://aoctrl.com/api/mcp/products/3RT1024-3KF40-1AA0","rawCanonicalId":null},"summary":{"shortDescription":"Siemens SIRIUS 3RT1024-3KF40-1AA0 power contactor, size S0, 110 V AC coil with integrated varistor, screw terminals, 45 mm width, snap-on DIN rail mount.","salesMarkdown":"The coil is rated 110 V AC and includes an integrated varistor surge suppressor, so you don't need to add a separate suppression module across the coil — one less part to wire and one less failure point to chase. Main power connections are screw-type terminals, accepting up to 2x 10 mm² or 1x 8 AWG stranded. The auxiliary and coil terminals take 2x (0.25...2.5 mm²) solid or 2x (1...2.5 mm²) stranded. The motor power ratings tell the real story: 7.5 kW at both 500 V and 690 V AC-3 duty. That means it switches a standard three-phase induction motor up to 7.5 kW on a 400 V or 690 V line — the AC-3 rating governs the load-break capability for starting and stopping a running motor, not just holding it closed. For heavy plugging or inching duty (AC-4), the contactor is rated 12.5 A at 400 V. The resistive-load rating (AC-12) maxes out at 10 A operating current — useful for switching heater banks or other non-inductive loads where the contactor sees no motor inrush. Short-circuit coordination matters for panel protection: with Type 2 coordination (limited damage to the contactor after a fault), the maximum fuse is gL/gG 25 A. Pick your fuse size based on which coordination level your panel design requires. Electrical life will be lower and depends on the switched current and duty cycle. ## Where it goes and what it tolerates That means it is suited for industrial control panels in factory environments, not for clean-room or sealed-cabinet use without derating. The front face carries IP20 finger protection — safe for panel installation where the front is accessible. The terminal area itself is IP00, meaning the wiring compartment is not touch-safe; that is normal for a panel-mounted contactor where the enclosure provides the overall protection. Side-by-side mounting is allowed without derating, which saves panel width when ganging multiple contactors. Because it is an active Siemens SIRIUS part, the compliance documentation you would expect is available: the manufacturer provides RoHS, REACH, and CE declarations, plus UL/CSA recognition through the SIRIUS product family certification. The varistor surge suppressor is built in, so the contactor meets the relevant IEC 60947-4-1 standards for motor starters. Sourcing posture: this is a quoted-to-order item through standard industrial distribution. Submit an RFQ with your quantity and target delivery window, and we will confirm lead time against the current factory backlog.","metaTitle":"Siemens SIRIUS 3RT1024-3KF40-1AA0 power contactor, S0, 110 V","metaDescription":"Siemens SIRIUS 3RT1024-3KF40-1AA0 power contactor, size S0, 110 V AC coil with varistor. Rated 7.5 kW at 690 V AC-3. Screw terminals, snap-on DIN rail mount. Current lifecycle stag","metaKeywords":null},"attributes":{"series":null,"packageCase":null,"mountingType":null,"rohsStatus":null,"productStatus":null,"categoryPath":["Contactors"],"specifications":{"Depth":"101 mm","Solid":"2x (0.25 ... 2.5 mm²)","Width":"45 mm","Height":"88 mm","Maximum":"2 000 m","At The Side":"6 mm","Rated Value":"110 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","lifecycle_stage":"current","During Operation":"-25 ... +60 °C","Full-scale value":"1.25","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":"7.5 kW","at 690 V rated value":"7.5 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":"5.5 kW","at AC-4 at 400 V rated value":"12.5 A","Design of the surge suppressor":"with varistor","Closing power of magnet coil at DC":"4.2 W","Holding power of magnet coil at DC":"4.2 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 (0.25 ... 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","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","For Short-Circuit Protection Of The Auxiliary Switch Required":"fuse gL/gG: 10 A"}},"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=295559&mlfb=3RT1024-3KF40-1AA0","alternativesUrl":"https://aoctrl.com/api/mcp/products/3RT1024-3KF40-1AA0/alternatives.json"},"ai":{"faq":[{"question":"What is the closest functional alternative — will the 3RT1023-1AL20 drop in?","answer":"The 3RT1023-1AL20 is a smaller frame size (S0 as well, but lower rating). It will not carry the same motor power — the 3RT1024-3KF40-1AA0 is rated 7.5 kW at 690 V AC-3, while the 3RT1023-1AL20 is a lower-current variant. Both share the same 45 mm width and DIN rail mounting, so they will physically fit the same panel footprint, but the coil voltage and rating differ. Check your load current against the 3RT1023's AC-3 rating before substituting."},{"question":"What is the depth of this contactor?","answer":"The depth is 101 mm from the mounting surface to the furthest projection."},{"question":"What wire sizes does the main terminal accept?","answer":"The screw terminals accept 2x (1...2.5 mm²), 2x (2.5...6 mm²), or a maximum of 2x 10 mm² stranded. In AWG: 2x (16...12), 2x (14...10), or 1x 8."},{"question":"Does this contactor have a built-in surge suppressor?","answer":"Yes. The design includes an integrated varistor across the coil, so no external suppression module is needed."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"matrix-langgraph","citationUrl":"https://aoctrl.com/siemens/3RT1024-3KF40-1AA0","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/3RT1024-3KF40-1AA0 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}}