Meeting the needs of the mining industry


Both above and below ground, Varispeed keeps the interests of its customers top of mind, all the time. The company was recently approached by a platinum mine to assist with a robust application. Three induction motors were required to run a conveyor belt at the mine. These motors had to pull and share the load simultaneously and this was achieved through the drooping control method. Projects and services engineer, Jonathan Molepo, says that this is done by limiting inrush currents to the motors, controlling the speed and protecting the motors from various faults that may occur during the process. In addition, the solution was required to operate 1500 meters underground, in a harsh and hot environment. The solution needed to be as user-friendly as possible to ensure quick and easy setup, reliable operation and drastically reduced belt stoppages.

“We looked to a 3-phase VSD motor that could drive the load. These motors were then mechanically coupled to a gear box for high torque and speed reduction and we installed 12 complete VSD panels” says Varispeed managing director, Ralph Real. Molepo adds that there was a careful balance between time to completion and the high quality required for this project. “The customer was pressed for time, so we needed to ensure a quick delivery whilst not compromising on the quality”. Varispeed took just under three weeks to build and deliver the 12 complete VSD panels. The customer has a five year warranty to ensure peace of mind.