{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"3RT1023-3BW40","brand":"Siemens","brandSlug":"siemens","productSlug":"3RT1023-3BW40","canonicalUrl":"https://aoctrl.com/siemens/3RT1023-3BW40","factsUrl":"https://aoctrl.com/api/mcp/products/3RT1023-3BW40","rawCanonicalId":null},"summary":{"shortDescription":"Siemens SIRIUS 3RT1023-3BW40 power contactor, Size S0, 4.5 kW at 400 V AC-3, 24 VDC coil, screw-type terminals.","salesMarkdown":"It delivers 4.5 kW at 400 V under AC-3 (cites:) and 5.5 kW at 690 V (cites:), making it a fit for three-phase induction motors in that power band. The 24 VDC coil draws 5.4 W both for closing and holding (cites:,), so the control transformer and power supply need to cover that inrush — it's a constant-gap magnet design, not a latching type. The AC-3 rating at 400 V (4.5 kW) is the one that governs most motor-start applications — that's the load-break rating for squirrel-cage motors under starting and running conditions. The AC-4 rating at 400 V (8.5 A) (cites:) covers plugging and inching duty, where the contactor opens under locked-rotor current; if your cycle includes frequent reversals or jogging, that 8.5 A figure is the hard limit, not the AC-3 kW number. For purely resistive loads (AC-12), the maximum operating current is 10 A (cites:). Short-circuit coordination is specified: with Type 1 coordination, a gL/gG fuse up to 63 A is required (cites:); with Type 2 coordination, the fuse limit drops to 25 A (cites:). Type 2 means the contactor remains fit for further service after a fault — important for production lines where a blown contactor means downtime. The auxiliary contact block handles 10 A at 24 V (cites:), 6 A at 230 V (cites:), and 3 A at 400 V (cites:). Those are the thermal ratings for the N/O and N/C contacts. Side-by-side mounting is allowed (cites:) with zero clearance between units — no derating for thermal stacking at rated current, but verify ambient temperature inside the enclosure. Main circuit terminals accept screw-type connections: 2x (1 to 2.5 mm²), 2x (2.5 to 6 mm²), or max 2x 10 mm² (cites:). AWG equivalents are 2x (16 to 12), 2x (14 to 10), or 1x 8 (cites:). The depth is 100 mm (cites:), width 45 mm (cites:), height 85 mm (cites:). Side clearance of 6 mm is needed for wiring access (cites:). Maximum operating altitude is 2000 m (cites:) — above that, derate for air density.","metaTitle":"Siemens 3RT1023-3BW40 SIRIUS Power Contactor, Size S0, 4.5 k","metaDescription":"Siemens SIRIUS 3RT1023-3BW40 power contactor, Size S0. Rated 4.5 kW at 400 V AC-3. Screw terminals, 24 VDC coil. Current lifecycle. Sourced to order against RFQ.","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","Maximum":"2 000 m","At The Side":"6 mm","Rated Value":"48 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":"4.5 kW","at 690 V rated value":"5.5 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":"4 kW","at AC-4 at 400 V rated value":"8.5 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 (0.25 ... 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","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=496661&mlfb=3RT1023-3BW40","alternativesUrl":"https://aoctrl.com/api/mcp/products/3RT1023-3BW40/alternatives.json"},"ai":{"faq":[{"question":"What is the closest functional alternative — the 3RT1023-1AL20?","answer":"The 3RT1023-1AL20 is a sibling in the same Size S0 frame, but the 3RT1023-3BW40 uses a 24 VDC coil while the -1AL20 uses a different coil voltage. The mechanical footprint and main current path are identical, so a panel designed for one can accept the other if the control voltage matches. Verify the coil rating before substituting."},{"question":"What are the key motor power ratings?","answer":"4.5 kW at 400 V AC-3 (cites:), 5.5 kW at 690 V AC-3 (cites:), 4 kW at 400 V AC-2 (cites:), and 8.5 A at 400 V AC-4 (cites:)."},{"question":"What fuse coordination is required?","answer":"Type 1 coordination requires a gL/gG fuse up to 63 A (cites:). Type 2 coordination requires a gL/gG fuse up to 25 A (cites:)."},{"question":"What is the mechanical service life?","answer":"10 million cycles typical (cites:). Electrical life depends on switching current and duty cycle."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"matrix-langgraph","citationUrl":"https://aoctrl.com/siemens/3RT1023-3BW40","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/3RT1023-3BW40 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}}