WEG is extending the application range of its plug-and-play CFW-11 variable-frequency inverter with IP54 variants. Integrating all of the innovative features of the standard CFW-11 drive, the IP54 versions offer extended scope for operation in harsh environments such as those found in food and beverage production plants.
In addition to providing safeguards for inverters used in tough applications, the IP54-rated CFW-11 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 options such as motor oversizing and additional ventilation; Optimal Flux is therefore a low-cost way to keep the motor's temperature within the thermal limits of its insulation class.
As well as delivering optimised control of motors, even at low speeds, the CFW-11 IP54 provides users with an easy-to-use, universal drive platform, offering plug-and-play technology that is automatically configured. Consequently the inverter can be used for a wide range of drive applications either as a standalone unit or in a centralised or decentralised network. This flexibility provides a wealth of integration possibilities, lowering total system costs while improving productivity. In addition, it enables users to standardise on one product for all types of variable-frequency drive (VFD) control, with the commensurate benefits of savings on equipment costs, inventory, training and maintenance requirements.
What makes the CFW11 so configurable is the number of features that combine to produce an overall systems platform. Most important is plug-and-play technology, which automatically recognises and configures accessories and option cards used for customisation, enabling easy installation while eliminating the cost and time taken for manual configuration.
With Universal Drive Selection the CFW11 IP54 can perform in V/f, VVW voltage vector, sensorless vector and vector encoder modes. Onboard Systems Modules tailor the drive both in terms of scaleable control (ie in replacing a PLC) and communications, with what is claimed to be one of the widest choices of fieldbus options (including Ethernet IP) available from any drive system. Normal and Heavy-Duty Ratings allow the drive to be adapted optimally to all types of load, and an onboard man-machine interface features a backlit graphic display and soft keys to facilitate inverter programming and monitoring. Built-in DC link inductors enable the inverter to comply with the IEC 61000-3-12 standard on harmonic suppression. Furthermore, cables up to 100m long can be used without the need for external line reactors.
The facility to customise the CFW-11 IP54 and achieve scaleable control systems tailored to OEM needs is realised with a total of 14 options cards covering: I/O (digital and analogue 14 bit A/Ds and D/As), PLC, encoder and communications. These simply clip into five slots on the CFW-11 IP54 and are recognised and configured, automatically. At any 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, they could be 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 option card for the CFW-11 IP54 provides a flexible, networkable alternative to a separate PLC in applications where the 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 a PLC-11 option card into the CFW-11 IP54, the user is able to perform general digital and analogue I/O control tasks, or 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 option card offers over 100 parameters via software or the onboard HMI, as well a real-time clock, timers, counters, coils and contactors. Users benefit from the flexibility of open, industry-standard programming using WEG's IEC 61131-3 programming software, and there is an RS485 interface for use with standard Modbus RTU.
Ensuring the safe and reliable operation of the CFW-11 are comprehensive protective features, including: intelligent thermal management, which enables full safeguarding of IBGTs, monitoring of heatsink and internal air temperature; automatic control of the fan via a speed sensor; and motor overload protection in compliance with IEC 60947-4-2/UL 508C.
In addition, the CFW-11 IP54 offers the options of a safety stop function in accordance with EN 954-1 category 3; an RFI filter in compliance with EN 61800-3 (internal) and the facility for an external 24V DC control feed.
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