The PQ monitor MEg38/C is intended for measuring and recording of four voltages and four currents, active and reactive powers and energies in three-phase LV, MV and HV networks. It analyses and evaluates voltage quality parameters on the voltages inputs U1,U2 and U3 in accordance with CSN EN 50160 ed. 3 and measurement methods of class S of CSN EN 61000-4-30 ed. 2. In the functions of quality measurement and in the functionof waveform recording, it evaluates all quantities without gaps and interruptions. The monitor MEg38/C can be used also for oscillographic recording of measured quantities enabled by events or voltages on the input U4. Using the user software functions, it is possible to select capacitor values of compensation batteries and set the breakdown switch value.