By Fernanda Knabben, marketing manager, WEG Middle East FZE
WEG Middle East is exhibiting its CFW-11 range of variable frequency drives (VFD) at ADIPEC 2010. Designed to optimise the energy efficiency of pump, fan and compressor motors in Oil and Gas applications, the CFW-11 range integrates ‘plug-and-play technology’ which makes it simple to programme and quick to install.
The CFW-11 provides users with an easy-to-use, universal drive platform, courtesy of plug-and-play technology that is automatically configured, enabling the inverter to suit the widest range of drive applications: standalone, centralised, and decentralised with networks. This flexibility provides a wealth of integration possibilities; lowering total system costs whilst improving productivity in addition, it enables users to standardise on one product for all types of VFD control, with the commensurate benefits of savings on equipment costs, inventory, training and maintenance requirements.
Available in ratings up to 370kW, the CFW-11 drives also offers users the benefits of WEG’s patented Optimal Flux technology. This minimises the losses of Totally Enclosed Fan-Cooled (TEFC) induction motors used with constant and variable torque loads, especially at low speeds where motor ventilation systems are inefficient. Optimal Flux overcomes the problem of reduced torque under these operating conditions, and the costs of traditional solutions such as motor oversizing and additional ventilation; providing instead an integrated, low cost solution for keeping motor temperature rise within the thermal limits of its insulation class.
The CFW-11 range is supported by a total of 14 optional cards – I/O (digital and analogue 14 bit A/Ds and D/As), PLC, Encoder and Communications. These help users to achieve scalable control systems tailored to their exact needs. The option cards simply clip into five slots on the CFW-11, and are automatically recognised and configured, eliminating manual input. At any one time, up to four of these modules – in any configuration – can be used on all CFW-11 drive versions.
In some systems they could be Fieldbus modules, providing gateway options for Fieldbuses such as Ethernet / IP, Profibus-DP, DeviceNet, CANopen and Modbus RTU. In others, a combination of encoder, softPLC modules (and communication modules) providing graduated levels of processing functionality in a standardised IEC 61131-3 programming environment.
The PLC-11 options card for the CFW-11 provides a flexible, networkable solution in applications where the frequency inverter on its own cannot provide the required level of control or interfacing. By removing the requirement for a separate PLC, it provides OEMs and users with substantial reductions in equipment, enclosure and installation costs. Simply by slotting-in a PLC-11 options card into the CFW-11, the drive user is able to perform general digital and analogue I/O control tasks, or to employ functions such as positioning with trapezoidal and “S” profiles (absolute and relative), master/slave synchronisation between two or more motors, or electronic gearbox.
The optional card offers the user over 100 parameters via software or HMI; a real time clock; timers counters, coils and contactors; the flexibility of open, industry standard programming using WEG’s IEC 61131-3 programming software; and the facility of an RS485 interface with standard Modbus RTU.
