{"product_id":"kl2791-beckhoff-single-phase-ac-motor-speed-controller-bus-terminal","title":"KL2791 BECKHOFF Bornier de bus contrôleur de vitesse moteur AC monophasé","description":"\u003ch3\u003eProduct Overview\u003c\/h3\u003e\n\u003cp\u003eThe\u003cspan\u003e \u003c\/span\u003e\u003cstrong\u003eKL2791 (KL2791)\u003c\/strong\u003e\u003cspan\u003e \u003c\/span\u003eis a specialized 1-phase AC motor speed controller designed to be integrated directly into the Beckhoff Bus Terminal system. Operating at a nominal voltage of\u003cspan\u003e \u003c\/span\u003e\u003cstrong\u003e230 V AC\u003c\/strong\u003e, this terminal provides a compact, DIN-rail mounted solution for controlling small single-phase AC motors with a power rating of up to\u003cspan\u003e \u003c\/span\u003e\u003cstrong\u003e200 VA\u003c\/strong\u003e. Unlike standard digital output terminals, the KL2791 utilizes advanced\u003cspan\u003e \u003c\/span\u003e\u003cstrong\u003ephase\/full-wave control\u003c\/strong\u003e\u003cspan\u003e \u003c\/span\u003elogic to adjust motor speed with a fine resolution of\u003cspan\u003e \u003c\/span\u003e\u003cstrong\u003e1%\u003c\/strong\u003e. This makes it an ideal choice for B2B industrial applications such as ventilation fan control, small pump modulation, and conveyor speed synchronization in HVAC systems or light assembly lines.\u003c\/p\u003e\n\u003ch3\u003eHardware Architecture and Control Logic\u003c\/h3\u003e\n\u003cp\u003eThe\u003cspan\u003e \u003c\/span\u003e\u003cstrong\u003eKL2791\u003c\/strong\u003e\u003cspan\u003e \u003c\/span\u003eis engineered to bridge the gap between low-voltage PLC logic and high-voltage motor actuation. It features a high degree of safety with\u003cspan\u003e \u003c\/span\u003e\u003cstrong\u003e3750 V AC\u003c\/strong\u003e\u003cspan\u003e \u003c\/span\u003eelectrical isolation between the power circuit and the K-bus logic, protecting the upstream bus coupler and CPU from voltage spikes.\u003c\/p\u003e\n\u003cp\u003eThe terminal operates via a\u003cspan\u003e \u003c\/span\u003e\u003cstrong\u003e16-bit data\u003c\/strong\u003e\u003cspan\u003e \u003c\/span\u003eprocess image, allowing for precise speed setpoints. The control electronics are powered via the K-bus, while the motor load is supplied through the 230 V AC power contacts. Its \"Direct Motor Connection\" technology eliminates the need for external triacs or interposing controllers, significantly reducing the complexity of the control cabinet. With a maximum output current of\u003cspan\u003e \u003c\/span\u003e\u003cstrong\u003e0.9 A\u003c\/strong\u003e, it is optimized for small-displacement motors where traditional frequency inverters would be cost-prohibitive or physically too large.\u003c\/p\u003e\n\u003ch3\u003eTechnical Specifications\u003c\/h3\u003e\n\u003ctable\u003e\n\u003cthead\u003e\n\u003ctr class=\"firstRow\"\u003e\n\u003ctd\u003e\u003cstrong\u003eAttribute\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003e\u003cstrong\u003eSpecification Details\u003c\/strong\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/thead\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cspan\u003e\u003cstrong\u003eModel\u003c\/strong\u003e\u003c\/span\u003e\u003c\/td\u003e\n\u003ctd\u003e\u003cspan\u003e\u003cstrong\u003eKL2791\u003c\/strong\u003e\u003c\/span\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cspan\u003e\u003cstrong\u003eBrand\u003c\/strong\u003e\u003c\/span\u003e\u003c\/td\u003e\n\u003ctd\u003e\u003cspan\u003e\u003cstrong\u003eBECKHOFF\u003c\/strong\u003e\u003c\/span\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cspan\u003e\u003cstrong\u003eNumber of Outputs\u003c\/strong\u003e\u003c\/span\u003e\u003c\/td\u003e\n\u003ctd\u003e\u003cspan\u003e1 Motor (Single-phase AC)\u003c\/span\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cspan\u003e\u003cstrong\u003eNominal Voltage\u003c\/strong\u003e\u003c\/span\u003e\u003c\/td\u003e\n\u003ctd\u003e\u003cspan\u003e230 V AC\u003c\/span\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cspan\u003e\u003cstrong\u003eRated Output Power\u003c\/strong\u003e\u003c\/span\u003e\u003c\/td\u003e\n\u003ctd\u003e\u003cspan\u003e≤ 200 VA\u003c\/span\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cspan\u003e\u003cstrong\u003eMax Output Current\u003c\/strong\u003e\u003c\/span\u003e\u003c\/td\u003e\n\u003ctd\u003e\u003cspan\u003e0.9 A\u003c\/span\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cspan\u003e\u003cstrong\u003eControl Principle\u003c\/strong\u003e\u003c\/span\u003e\u003c\/td\u003e\n\u003ctd\u003e\u003cspan\u003ePhase control \/ Full wave control\u003c\/span\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cspan\u003e\u003cstrong\u003eResolution\u003c\/strong\u003e\u003c\/span\u003e\u003c\/td\u003e\n\u003ctd\u003e\u003cspan\u003e1 %\u003c\/span\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cspan\u003e\u003cstrong\u003eLeakage Current (OFF)\u003c\/strong\u003e\u003c\/span\u003e\u003c\/td\u003e\n\u003ctd\u003e\u003cspan\u003e\u0026lt; 1 mA\u003c\/span\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cspan\u003e\u003cstrong\u003eIsolation (K-bus\/Field)\u003c\/strong\u003e\u003c\/span\u003e\u003c\/td\u003e\n\u003ctd\u003e\u003cspan\u003e500 V (Signal) \/ 3750 V AC (Testing)\u003c\/span\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cspan\u003e\u003cstrong\u003eCurrent Draw (K-bus)\u003c\/strong\u003e\u003c\/span\u003e\u003c\/td\u003e\n\u003ctd\u003e\u003cspan\u003eTypically 95 mA\u003c\/span\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cspan\u003e\u003cstrong\u003eDimensions (W x H x D)\u003c\/strong\u003e\u003c\/span\u003e\u003c\/td\u003e\n\u003ctd\u003e\u003cspan\u003e12 mm x 100 mm x 68 mm\u003c\/span\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cspan\u003e\u003cstrong\u003eOperating Temp\u003c\/strong\u003e\u003c\/span\u003e\u003c\/td\u003e\n\u003ctd\u003e\u003cspan\u003e0 to +55 Celsius\u003c\/span\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cspan\u003e\u003cstrong\u003eProtection Rating\u003c\/strong\u003e\u003c\/span\u003e\u003c\/td\u003e\n\u003ctd\u003e\u003cspan\u003eIP20\u003c\/span\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003ch3\u003eTechnical FAQs\u003c\/h3\u003e\n\u003cp\u003e\u003cstrong\u003eWhat is the difference between Phase Control and Full Wave Control on the KL2791?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003ePhase control (leading or trailing edge) clips the AC sine wave to reduce the effective voltage delivered to the motor, suitable for speed regulation. Full wave control can be used for zero-cross switching to minimize electromagnetic interference when toggling the motor state.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eCan the KL2791 be used for 3-phase motors?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eNo. The\u003cspan\u003e \u003c\/span\u003e\u003cstrong\u003eKL2791\u003c\/strong\u003e\u003cspan\u003e \u003c\/span\u003eis strictly designed for\u003cspan\u003e \u003c\/span\u003e\u003cstrong\u003e1-phase AC motors\u003c\/strong\u003e\u003cspan\u003e \u003c\/span\u003ewith a maximum load of 200 VA. For 3-phase applications, a Beckhoff frequency inverter (Distributed or Drive series) should be utilized.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eIs external fuse protection required?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eWhile the terminal is robust, it does not feature integrated reverse voltage protection. It is highly recommended to install a fast-acting fuse or motor starter upstream on the 230 V AC supply line to protect the terminal and motor from short-circuit conditions.\u003c\/p\u003e\n\u003chr\u003e\n\u003ch3\u003eEngineering \u0026amp; Installation Guide\u003c\/h3\u003e\n\u003cul class=\"list-paddingleft-2\"\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong\u003eMotor Compatibility:\u003c\/strong\u003e\u003cspan\u003e \u003c\/span\u003eEnsure the motor is compatible with phase-cut dimming or voltage regulation. Some capacitor-start motors may require a minimum speed setting in the PLC program to ensure sufficient torque for starting and to prevent overheating at low RPMs.\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong\u003eWiring and Termination:\u003c\/strong\u003e\u003cspan\u003e \u003c\/span\u003eUse the pluggable\u003cspan\u003e \u003c\/span\u003e\u003cstrong\u003eKS series\u003c\/strong\u003e\u003cspan\u003e \u003c\/span\u003ewiring for easier maintenance. Ensure that the 230 V AC supply is connected to the correct power contacts. Given the high-voltage nature of this terminal, use wires with a minimum insulation rating of 300 V and keep motor leads as short as possible to reduce EMI.\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong\u003eThermal Management:\u003c\/strong\u003e\u003cspan\u003e \u003c\/span\u003eThe KL2791 generates heat when operating near its\u003cspan\u003e \u003c\/span\u003e\u003cstrong\u003e0.9 A\u003c\/strong\u003e\u003cspan\u003e \u003c\/span\u003elimit. Maintain vertical installation on the DIN rail to allow for natural convection. If multiple KL2791 terminals are installed side-by-side, ensure the cabinet temperature does not exceed\u003cspan\u003e \u003c\/span\u003e\u003cstrong\u003e55 Celsius\u003c\/strong\u003e\u003cspan\u003e \u003c\/span\u003eto prevent thermal derating.\u003c\/p\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003eEngineering Advantages\u003c\/h3\u003e\n\u003cp\u003eThe\u003cspan\u003e \u003c\/span\u003e\u003cstrong\u003eKL2791\u003c\/strong\u003e\u003cspan\u003e \u003c\/span\u003estands out for its ability to integrate high-voltage motor control into a standard\u003cspan\u003e \u003c\/span\u003e\u003cstrong\u003e12 mm\u003c\/strong\u003e\u003cspan\u003e \u003c\/span\u003eI\/O slice. By eliminating the need for standalone speed controllers, it reduces the total bill of materials (BOM) and panel labor costs. Its compliance with\u003cspan\u003e \u003c\/span\u003e\u003cstrong\u003eEN 61000-6-2\/4\u003c\/strong\u003e\u003cspan\u003e \u003c\/span\u003efor EMC immunity and emission ensures that the phase-cutting noise does not disrupt sensitive analog signals in the same terminal block. For engineers, the 16-bit resolution provides granular control over airflow or fluid pressure, making it a \"smart\" alternative to simple ON\/OFF relays for AC motor management.\u003c\/p\u003e\n\u003cp\u003e \u003c\/p\u003e","brand":"BECKHOFF","offers":[{"title":"Default Title","offer_id":53106700976491,"sku":"KL2791","price":100.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0953\/3227\/0443\/files\/kl2791-ybdjoaaw3uz.png?v=1776245145","url":"https:\/\/www.plcprotech.com\/fr\/products\/kl2791-beckhoff-single-phase-ac-motor-speed-controller-bus-terminal","provider":"PLC ProTech Ltd.","version":"1.0","type":"link"}