Currently several methodologies exist to assess the Responsibilities Assignment Problem in Power Quality. In this paper an experimental setup with two known disturbing electrically and mechanically coupled loads has been used to provide a reference disturbance setup for comparing these methodologies. The results and discussion extracted from this experiment is reported in this paper. The setup offered the possibility of adjusting the active power direction under several operative conditions and under two different feeding network configurations. Quantities defined in the standards IEEE 1459 and DIN 40110 are also employed to broaden the analysis and diagnostic possibilities.