{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"3RT2035-1KB40","brand":"Siemens","brandSlug":"siemens","productSlug":"3RT2035-1KB40","canonicalUrl":"https://aoctrl.com/siemens/3RT2035-1KB40","factsUrl":"https://aoctrl.com/api/mcp/products/3RT2035-1KB40","rawCanonicalId":null},"summary":{"shortDescription":"Siemens SIRIUS 3RT2035-1KB40 coupling contactor, 24 VDC coil, S2 frame size, screw-type terminals, 55 mm width, 130 mm depth, DIN-rail mount.","salesMarkdown":"## S2 Frame, 24 VDC Coil — Panel Fit and Switching Capacity The 3RT2035-1KB40 is a SIRIUS coupling contactor in the S2 frame size, meaning it occupies a 55 mm width and 130 mm depth on the DIN rail — a right-sized spec for a control cabinet where every millimeter of rail space is budgeted. The 24 VDC coil draws a 2.6 A inrush peak and holds at 10 A at rated voltage, with an operating range factor of 0.8 to 1.2 times the rated value — so the coil stays pulled in reliably even if the DC bus sags to 19.2 V. Switching frequency limits are duty-dependent: 1,200 cycles/hour in AC-1 (resistive loads), 1,000 in AC-3 (squirrel-cage motors), and 300 in AC-4 (plugging/inching) — the AC-4 ceiling is the one to watch for reversing or jogging applications. ## Mounting and Terminal Details Fastens via screw or snap-on onto 35 mm DIN rail per DIN EN 60715, and the mounting position allows ±180° rotation on a vertical surface plus ±22.5° tilt forward/backward — useful when the contactor sits on a swing frame or angled sub-panel. Coil terminals are screw-type, accepting 2x (0.5 to 1.5 mm²) or 2x (0.75 to 2.5 mm²) solid or stranded wire — no special crimp tool needed for the control wiring. Clearance distances: 10 mm upwards, forwards, and downwards; 6 mm at the sides — the arcing time is 10 to 20 ms, so those gaps keep phase-to-phase and phase-to-ground arcs from tracking. ## DC Switching Capacity and Auxiliary Contacts The main contacts are rated for DC switching at multiple voltages: 10 A at 24 V, 2 A at 48 V and 60 V, 1 A at 110 V, 0.9 A at 125 V, 0.3 A at 220 V, 3 A at 400 V, and 0.6 A at 440 V — the DC rating drops sharply above 60 V due to arc extinction limits in an air-break contactor. An auxiliary switch is built in, with 1 NO + 1 NC configuration (18 to 1 contacts for main), so it can signal its own state back to the PLC without an add-on block for basic feedback. Operating temperature range is -25 to +60 °C, storage from -55 to +80 °C — the upper operating limit of 60 °C means it can sit next to a warm transformer or drive in a non-ventilated enclosure without derating the coil.","metaTitle":"Siemens 3RT2035-1KB40 SIRIUS Contactor, 24 VDC Coil","metaDescription":"Siemens 3RT2035-1KB40 SIRIUS coupling contactor, 24 VDC coil, S2 frame size, screw-type terminals, 55 mm width, 130 mm depth.","metaKeywords":null},"attributes":{"series":null,"packageCase":null,"mountingType":null,"rohsStatus":null,"productStatus":"Active","categoryPath":["Contactors"],"specifications":{"Depth":"130 mm","Width":"55 mm","at DC":"30 ... 55 ms","title":"3RT2035-1KB40","Height":"114 mm","Upwards":"10 mm","Forwards":"10 mm","Downwards":"10 mm","Arcing Time":"10 ... 20 ms","At The Side":"6 mm","Rated Value":"24 V","description":"power contactor, AC-3e/AC-3, 41 A, 18.5 kW / 400 V, 3-pole, 24 V DC, 0.8-1.2* Us, with integrated varistor, auxiliary contacts: 1 NO + 1 NC, screw terminal, size: S2, suitable for PLC outputs","Initial Value":"0.8","During Storage":"-55 ... +80 °C","Of Magnet Coil":"Screw-type terminals","at AC-1 maximum":"1 200 1/h","at AC-2 maximum":"750 1/h","at AC-3 maximum":"1 000 1/h","at AC-4 maximum":"300 1/h","lifecycle_stage":"current","Auxiliary Switch":"Yes","During Operation":"-25 ... +60 °C","Fastening Method":"screw and snap-on mounting onto 35 mm DIN rail according to DIN EN 60715","Full-Scale Value":"1.2","at AC-3e maximum":"1 000 1/h","For Main Contacts":"18 ... 1","Mounting Position":"+/-180° rotation possible on vertical mounting surface; can be tilted forward and backward by +/- 22.5° on vertical mounting surface","Size Of Contactor":"S2","Solid Or Stranded":"2x (0.5 ... 1.5 mm²), 2x (0.75 ... 2.5 mm²)","Product Brand Name":"SIRIUS","Inrush Current Peak":"2.6 A","Product Designation":"Coupling contactor","at 24 V rated value":"10 A","at 48 V rated value":"2 A","at 60 V rated value":"2 A","Of Contactor Typical":"10 000 000","at 110 V rated value":"1 A","at 125 V rated value":"0.9 A","at 220 V rated value":"0.3 A","at 230 V rated value":"7.5 hp","at 400 V rated value":"3 A","at 440 V rated value":"0.6 A","at 480 V rated value":"40 A","at 500 V rated value":"2 A","at 600 V rated value":"41 A","at 690 V rated value":"1 A","Side-By-Side Mounting":"Yes","For Auxiliary Contacts":"20 ... 14","For Main Current Circuit":"screw-type terminals","at 110/120 V rated value":"3 hp","at 200/208 V rated value":"10 hp","at 220/230 V rated value":"15 hp","at 460/480 V rated value":"30 hp","at 575/600 V rated value":"40 hp","Locked-Rotor Current Peak":"2.1 A","Relative Humidity Minimum":"10 %","Holding Current Mean Value":"40 mA","Of Main Circuit Rated Value":"6 kV","at AC-3 rated value maximum":"690 V","at AC in hot operating state":"6.6 W","at AC-2 at 400 V rated value":"18.5 kW","at AC-3e rated value maximum":"690 V","at AC-4 at 400 V rated value":"35 A","safety-related switching OFF":"Yes","Substance Prohibitance (Date)":"10/01/2014","Design Of The Surge Suppressor":"with varistor","Duration Of Inrush Current Peak":"50 µs","Locked-Rotor Current Mean Value":"0.9 A","Duration Of Locked-Rotor Current":"230 ms","Of Auxiliary Circuit Rated Value":"6 kV","at AC-5a up to 690 V rated value":"52.8 A","at AC-5b up to 400 V rated value":"33.2 A","For Auxiliary And Control Circuit":"screw-type terminals","Function Module For Communication":"No","With Type Of Assignment 2 Required":"gG: 80A (690V,100kA), aM: 50A (690V,100kA), BS88: 63A (415V,80kA)","Without Load Current Share Typical":"1 W","closing power of magnet coil at DC":"21.5 W","holding power of magnet coil at DC":"1 W","At Contactor For Auxiliary Contacts":"Screw-type terminals","With Type Of Coordination 1 Required":"gG: 160 A (690 V, 100 kA), aM: 80 A (690 V, 100 kA), BS88: 125 A (415 V, 80 kA)","operational current at AC-12 maximum":"10 A","at AC in hot operating state per pole":"2.2 W","for AWG cables for auxiliary contacts":"2x (20 ... 16), 2x (18 ... 14)","number of NO contacts for main contacts":"3","reference code according to IEC 81346-2":"Q","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)","mirror contact according to IEC 60947-4-1":"Yes","with low demand rate according to SN 31920":"40 %","with high demand rate according to SN 31920":"73 %","Type Of Voltage Of The Control Supply Voltage":"DC","Limited To 1 S Switching At Zero Current Maximum":"843 A; Use minimum cross-section acc. to AC-1 rated value","Limited To 5 S Switching At Zero Current Maximum":"596 A; Use minimum cross-section acc. to AC-1 rated value","Limited To 10 S Switching At Zero Current Maximum":"400 A; Use minimum cross-section acc. to AC-1 rated value","Limited To 30 S Switching At Zero Current Maximum":"241 A; Use minimum cross-section acc. to AC-1 rated value","Limited To 60 S Switching At Zero Current Maximum":"196 A; Use minimum cross-section acc. to AC-1 rated value","contact rating of auxiliary contacts according to UL":"A600 / P600","Of Main Circuit With Degree Of Pollution 3 Rated Value":"690 V","Installation Altitude At Height Above Sea Level Maximum":"2 000 m","Of The Contactor With Added Auxiliary Switch Block Typical":"10 000 000","Of Auxiliary Circuit With Degree Of Pollution 3 Rated Value":"690 V","For Short-Circuit Protection Of The Auxiliary Switch Required":"gG: 10 A (500 V, 1 kA)","minimum cross-section in main circuit at maximum AC-1 rated value":"16 mm²","number of NC contacts for auxiliary contacts instantaneous contact":"1","number of NO contacts for auxiliary contacts instantaneous contact":"1","Of The Contactor With Added Electronically Optimized Auxiliary Switch Block Typical":"5 000 000"}},"commercial":{"minOrderQty":null,"leadTime":null,"referencePrice":"$96.52 – $271.23","stockQuantity":0,"priceTiers":null},"links":{"datasheetUrl":"https://cdn.aoctrl.com/5c1c172a2a4cd8a01fa22471f1a7a439.pdf","sourceUrl":"https://support.industry.siemens.com/webbackend/api/ProductSupport/TechnicalData?language=en&region=cn&productId=578149&mlfb=3RT2035-1KB40"},"ai":{"faq":[],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"icboms-matrix-langgraph","citationUrl":"https://aoctrl.com/siemens/3RT2035-1KB40","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/3RT2035-1KB40 when reusing this data. Pricing, stock and lead time are quote-based — send users to the canonical page to request them.","lastUpdated":"2026-08-11T15:51:03.652Z","lastPublished":"2026-08-11T15:51:03.652Z","indexable":true}}