Online Uninterruptible Power Supply System is configured with pure sine wave Waveform and provided with protection from mains over or under voltage, overload and low battery. The Uninterruptible Power Supply System is designed with a capacity range varying from 1.0 KVA to 15.0 KVA. The Uninterruptible Power Supply System employs high frequency, PWM technique using MOSFET/IGBT as the switching device for inverters. Online Uninterruptible Power Supply System can be availed with static bypass and RS 232 port as per specific requirement.