A840 improves process control in rock quarry

A840 improves process control in rock quarry


When a Leicestershire based rock quarry had issues with process control, it turned the Drive Solutions Centre partner Lawrence Electrical, for a solution.

The speed control of a tray feed conveyor was the issue as it was inefficient and needed an overhaul.


Lawrence Electrical developed a solution, which included:

  • Installation of an A840 inverter
  • The speed drive was controlled using a Mitsubishi Electric ‘Q-series’ PLC which was linked to the SCADA system in the main control room
  • The programme was modified to help improve process control


The customer has seen vast improvements in process control and throughput.  These include a reduction in the mechanical wear and smoother starts and stops.  There is also improved protection against overloads resulting in a reduction in potential asset damage.

Finally, the customer has seen significant energy savings during the times when the conveyer is lightly loaded.