On line UPS The primary purpose of the GENUS On - Line UPS System is to protect critical and sensitive equipment from the electrical disturbances that may jeopardize their operation. Mains - line failures, mini blackouts high and low voltage fluctuations, lighting electrostatic discharge and rapid over - voltage are phenomena found in all environments causing damage to hardware and loss of data. When the mains rectifies it and the back up batteries are kept in a constantly charged state. When the mains supply fails the source of DC power for the inverter section shifts to the battery without any break whatsoever in the output.