A food processing client operating a high-speed centrifuge for separating animal food substances (tallow and greaves) identified significant safety concerns. The centrifuge, which carries a substantial load at 14000 RPM, lacked a variable speed drive, posing a risk to operators who needed to access the top cover. The primary safety requirement was to ensure the centrifuge came to a complete and verified stop before the operator could open the cover, thereby preventing serious injury.

To address this critical safety requirement, a comprehensive control and safety system was designed and implemented. This included the supply of a Variable Speed Drive (VSD), housed in a dedicated enclosure, which not only controlled the motor but also provided controlled braking functionality. A Siemens S7-1200 PLC and associated display panel were installed to manage the overall operation and safety logic.

Key safety features integrated into the system included the installation of proximity switches to verify the correct positioning of brakes before the centrifuge could start, and positioning switches to accurately monitor the shaft speed. A unique safety key locking mechanism was also incorporated; this system required the operator to physically lock the centrifuges top cover with a key, which then had to be inserted into a panel located a safe distance away before the machine could be enabled to start. An emergency stop (E-stop) button was also provided for immediate shutdown in critical situations. The VSDs ability to act as a controlled brake was central to achieving the required rapid and safe deceleration. This integrated solution ensured that the centrifuges top cover could only be accessed when the machine was completely stopped, significantly enhancing operator safety.