WEG launches decentralised drive package with WG20 geared motors and MW500 VSDs

When compared with traditional drives, this compact, decentralised drive solution from WEG provides users with a wide range of benefits. With lower energy consumption and a compact footprint, the package is far more efficient overall than centralised drive solutions. At the same time, it ensures the user enjoys maximum flexibility. The decentralised drive package can be utilised for a broad spectrum of applications, including machines in intralogistics such as warehouse systems and conveyor belts. Other applications include speed controlled fan pumps and filling systems as used in the food industry.

Decentralised drives save space in switch cabinets 
“By combining the MW500 VSD designed as a decentralised solution and the WG20 gear unit with a EUSAS integral motor, we’re demonstrating just how compact, powerful and efficient drive solutions can be,” says Norbert Reisner, who heads up the Product Engineering Dept. at WEG subsidiary Watt Drive. “When it comes to decentralised indoor and outdoor applications, the MW500 VSD family makes a good pairing with geared motors from the WG20 series. This combination is the perfect solution when users need variable-speed drives while simultaneously cutting energy requirements.”

Further benefits of decentralised drive solutions
Compared to centralised solutions, a decentralised drive system can also be networked more easily with standard industrial bus systems. Another major advantage of decentralised solutions is that several drives can be connected via separate bus systems while the supply line is then looped through, allowing for considerably shorter cable lengths. This is in contrast to a switch cabinet solution where every drive has to be wired to the inverter in the switch cabinet. A decentralised drive is also easy to install and maintain. Combining the WG20 geared motor with a decentralised variable speed drive provides independent control of speed and torque. This is an effective way to conserve energy while ensuring the required power is always available.

When the WG20 gear unit in this setup is then connected to a EUSAS integral motor from WEG, this offers a wide range of advantages for the user, because the EUSAS motor operated in frequency inverter mode (100/120 Hz characteristics) offers double the power at a constant torque.

EUSAS motor: 100/120 Hz – double the power with MW500
Significant benefits are achieved when using WG20 gear units and MW500 variable speed drives together with WEG EUSAS motors operated at 100/120 Hz. These motors can be deployed in EUrope, the USA or ASia, since they support a broad range of voltages and also offer the option of voltage switching. As with all WG20-series geared motors, the EUSAS motor can control each individual drive in frequency inverter mode with a variable speed as the situation requires. In this case, the MW500 must be dimensioned to match the doubled motor power and have the right parametric design to use the benefits of the overall package to the full. At low frequencies, forced cooling can also be used to achieve a constant torque: this results in a broad usage spectrum ranging from low to very high speeds. When combined with modern variable speed drives like the MW500, the result is a high-performance, variable-speed drive with double the power at a constant torque across a wide range of speeds.

Constant torques up to 100/120 Hz
Thanks to the special winding, a drive with a EUSAS motor can operate at higher speeds and deliver higher power output at a constant magnetic flux (constant torque) without overloading the machine. In this way, the EUSAS motors make excellent use of the capabilities of electronically controlled drive technology. The ability to work with twice the rated power in inverter mode creates more scope in confined installation situations while also enabling applications that require a wide control range (speed range) with constant torque up to 100/120 Hz. The use of smaller motors, even for demanding performance requirements, reduces weights while also cutting costs.

MW500: Rugged design for indoor and outdoor applications
The heavy-duty housing design for the MW500 with an IP66 and NEMA 4X rating means that the VSD can be attached directly to the motor terminal box frame or (with an adapter plate) to the wall, making it ideal for outdoor applications. This removes the need for motor cabling and the switch cabinet, which reduces the effort and costs for installation and commissioning. As a result, users can install the MW500 near to the motor to be controlled, which boosts deployment flexibility.

Energy savings offer clear benefits 
The MW500 also comes with an energy-saving feature out of the box, which enables the motor voltage to be reduced when loads are light. This offers significant energy savings, especially for partial loads.
 
Comprehensive specification – simple operation
In the standard variant, the MW500 features a PID process controller and an integrated PLC with a wide range of programmable functions, plus support both for voltage vector control (VVW) and V/f characteristic curve control. An RFI filter (category C2, according to EN 61800-3) is integrated. An analogue speed setpoint potentiometer is also included in the inverter: this can be used to control the speed of an asynchronous motor without requiring the use of a remote control unit (HMI). If required, however, users can also operate the unit with a simple, user-friendly remote control unit (HMI, optional). Three LEDs placed on the top surface of the inverter are used to indicate operational, alarm and error states. Another option is a built-in mains isolation switch, to ensure safe and straightforward maintenance. A special coating (IEC 60721-3-3, category 3C2), protects the electronic boards in the MW500 from dust, moisture and chemicals. The inverter has CE, cUL and EAC certification.

To maximise the versatility of the unit, optional extension modules available for the MW500 include digital inputs and outputs, as well as communication protocols such as CANopen, DeviceNet and PROFIBUS-DP. The Windows-based application software SuperdriveG2 is used for MW500 settings, control and monitoring, and is available as a free download from the WEG website.