The grid feeding monitoring relays CM-UFD.M*M are designed to monitor the voltage and the frequency of the public low voltage or medium voltage grid. Whenever the measured values are not within the range of the adjusted threshold values, the CM-UFD.M*M causes tripping of the section switch (consisting of 1 or 2 switching devices according to the applicable standard). This tripping disconnects the power generation, such as photovoltaic systems, wind turbines, block-type thermal power stations from the grid.