Abstract: A compressor unit including a compressor is provided. The compressor unit includes a suction line and a discharge line, a control unit which controls the compressor and/or adjacent modules. A method to operate a compressor unit is also provided. To avoid any damage caused by non-gaseous fluid amount at least one detection device is disposed in the suction line to identify non-gaseous fluid amounts in the fluid to be compressed before entering the compressor. The detection device is connected to the control unit in a signal transmitting manner.