is used in the energy supply systems of induction furnaces and on the induction furnaces themselves. The cooling water volumes and cooling water tempera- tures in the return limes are monitored. In frequency converter systems, the max- imum supply temperature must not exceed 34 °C, and the return temperature should be a maximum of 40 °C. Due to the precipitation of limescale, the maxi- mum return temperature of induction furnaces should not exceed 72 °C. Formerly, mechanical flow controls were used, which worked by means of coun- terbalance weights. Since the introduction of electronics however, more and more electronic devices are being used, which have also proven themselves in principle. However, it often happens that these devices indicate a throughflow, but the calculated volume does not correspond to the actual throughflow. The display may shut down after a short time, especially in cooling water circuits with high electrical currents.
