Quarry Southern Africa September 2017 | Page 10

Shaw Controls, a Zest WEG Group company, has supplied a containerised electrical solution to supply power for driving a mill on a new gold mine in West Africa. “Containerised electrical solutions are becoming increasingly popular, as these allow for speed of installation, and they are a particularly cost-effective option for mines and plants operating in Africa,” says Kirk Moss, medium voltage manager at Shaw Controls. The custom-engineered substation comprises a medium voltage (MV) WEG MVW01 variable speed drive (VSD) and a dry type phase shift transformer driving a 2 000kW, six-pole, 6.6kV squirrel cage WEG electric motor. The VSD is housed in the container, while the oil-cooled transformer is housed outside of it to facilitate heat dissipation. According to Moss, the solution has been specifically engineered for this particular application and uses specialised software for frozen charge protection. The software, which interfaces with the VSD, allows for the objective detection of a frozen charge Shaw Controls supplies containerised electrical solution at West African gold mine The custom-engineered substation supplied by Shaw Controls to a mine in Mali. The WEG medium voltage 6.6kV variable speed drive prior to installation into the container. condition by making use of torque measurements already being monitored by the VSD. “With the addition of an encoder fitted to the electric motor, we are now able to monitor mill angle. And with the torque and angle measurements it is possible to detect if cascading has occurred within the mill,” he explains. A user-friendly interactive touch screen has been configured to allow different levels of access to relevant data. The ability to extract the most relevant data and provide this in an intuitive Kirk Moss, medium voltage manager at Shaw Controls. 8 _ QUARRY SA | SEPTEMBER 2017 and simplified format allows both operational and service personnel to monitor the requisite parameters. The WEG MVW01 VSD range is available in 3.3kV and 6.6kV versions. Also available is the WEG MVW3000 (3.3kV, 6.6kV, and 11kV).