Within the Project seeks to answer the following questions: 1) Where do themselves RF PQ disturbances and how to translate that for the device (action uncertain, flickering of LED early failure, ...)? 2) which combination (s) of devices diver problems? 3) What is the probability that these problems occur and what are the practical implications? 4) Can these problems be predicted, for example, by measuring with an on-line impedance meter? 5) What measures - preventive and corrective - are possible to avoid such problems in the future and what are the advantages and disadvantages of these measures?