Isolated Double Conversion On Line Uninterrupted Power Supply is provided with an easy-to-read LED / LCD display which clearly provides real-time power status and communicates all major system parameters and system status including input voltage, output voltage etc. The Uninterrupted Power Supply is designed with output isolated transformer which segregates the input and output completely in the inverter mode, which provides great advantages of noise rejection as well as a safer neutral line to the load. The Uninterrupted Power Supply is designed with automatic and manual bypass facility which ensures continuous supply of power to the critical load in the event of electronic failure, overload, overheat or scheduled maintenance. Isolated Double Conversion On Line Uninterrupted Power Supply is designed with communication software which allows the user to remotely test the major operating functions of the UPS.