With commissioning of a small combined heat and power plant in the customers installation, the whole control system of the building failed with field bus errors. The field bus errors caused some wrong measurements and control signals and parts of the plant were shut down for safety reasons. On the basis of our detailed report and its proposed solutions, the suppliers were able to repair the most important defects in the installation of the M-Bus, Profibus and Modbus-components by themselves.

After installation of a new photovoltaic system in a low-voltage grid with high amount of drives, frequent failures of the first and larger solar system have been detected. A power quality measurement, conducted by the local utility company, was showing temporarily high voltage distortions and exceedances of the limits in accordance with EN 50160 as well as EN 61000-2-2. As a quick fix option, a special active filter was installed and has been parametrized by PQP.