3-phase installations are applied in case of long lasting or continuous use (e.g. in production processes) and in larger premises which need to be vacuumed by several persons simultaneously. With a 3-phase power unit you can vacuum up to 12 persons simultaneously. In addition, 3-phase machines are used with (explosive) hazardous dust. Would you like to know more about 400V installations? Then take a look at our  InDust  website.