Wireless Pump Control


Water needed to be pumped -2.5km away from the quarry up a hill to act as the water supply reservoir to the PPC main building and gardens. For this to be possible a wireless link was needed between the pump station down at the quarry and the reservoir up the hill. The client also wanted to report data to the SCADA room some 1.5km away from the reservoir.

The overall objective of the wireless pump project, was to maintain a certain reservoir level at all times by pumping from the newly build dam at the bottom of the hill (quarry). Level control is possible via the wireless radio link established between the pump station and the reservoir level sensor. It indicates the exact level of the reservoir and hence start/stop the 55kW motor and pump. In auto mode pumping is restricted to afterhours which are leading to cheaper electricity usage.

Crusher Monitoring


The main objective of this project was to monitor the secondary and tertiary crushers on the crushing plant of Lafarge to prevent them from overheating. The control system was implemented on the secondary and tertiary sections of a crushing plant to monitor the two crushers and prevent them from overheating.

Parameters to be monitored included: oil temperatures, pressures, running hours etc. It provided the operator with real-time information from the plant via a user-friendly human machine interface. Interlocking was added between motors as well as fault detection from the main soft starters. A remote start/stop control station was also added to give user the ability to review the alarm history.

Manganese Seperator


The slurry separating control system was implemented mainly to separate the unwanted form of manganese with the good and high grade. It works on the principle of pulsating water with air and PID control from a programmable logic controller, controlling the in-feed conveyor to maintain a constant level of ore in the separation bins.

PLC was used to control six VSD’s using the PLC’s analog outputs. A laser sensor on a mechanical float measured the level inside the bin. The following settings could be set on the HMI; Level, pulsating speed, in feed speed as well as out feed speed. The control system also controlled the generator settings and conveyor controllers. A SMS function was also added to send process relative information such as ore quantities and alarm conditions to the user daily.

VSD Replacement


HmT Mechatronics was approached by N1 Pavers & Blocks to replace a beyond economical repair Danfoss VSD unit, which controls two 7.5kW vibration motors on one of their brick plants. Vibration motor speed plays a vital role in the quality of brick manufactured. The higher the speed of the motor, the higher the density as well as quality the end product has.

An installed Festo PLC controls the vibration motor speed via the VSD on a 4-20mA current signal. There is also a HMI that enables the operator to alter the running- & JOG speeds in conjunction with the motor direction.