mining

Both above and below ground, Varispeed keeps the interests of its customers top-of-mind, all the time. Varispeed was recently approached by a platinum mine in South Africa to assist with a robust application requirement.

The challenge
Three induction motors were required to run a conveyor belt at the mine. These motors had to pull and share the load simultaneously which was achieved through the drooping control method. 

Jonathan Molepo, Projects and Services Engineer for Varispeed 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, our solution was required to operate 1500 meters underground, in a harsh and hot environment”. 

In terms of location, the motors were a long walking distance away, so they needed to be as ‘self-sufficient’ as possible. “Our solution needed to be as user-friendly as possible to ensure a quick and easy set-up, reliable operations and drastically reduced belt stoppages”. 

“We looked to a 3-phase VSD motor that could drive the particular load. These motors were then mechanically coupled to a gear box for high torque and speed reduction, and we installed 12 complete VSD panels for this request” says Ralph. 

Success! 
Jonathan says that there was a careful balance between time to complete vs. 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 received the order and it took just under 3 weeks after receiving the approved drawings to build and deliver the 12 complete VSD panels and the customer has a 5 year warranty to ensure peace of mind!