The VLT® 8000 AQUA Series variable frequency drives from Danfoss Water and Wastewater now provide Enhanced Sleep Mode with the capability to detect run-dry conditions in open loop operation. Users simply enter two sets of values for power and frequency (maximum or minimum) at zero flow. The drive then automatically calculates all data in between those two sets of values and generates a frequency/power curve for no flow. Users can also choose to set the drive for manual or automatic restart.