On Line Uninterrupted Power Supply System works on a power supply rate of 230V ±20 %, in single phase mode or 415V / 230V ±20 %, in three phase mode with four wires. The Uninterrupted Power Supply System functions at a frequency rate of 50Hz, ± 10%. The On Line Uninterrupted Power Supply System gives indication on several conditions such as mains on - UPS on - charger on - battery low and over load trip. The Uninterrupted Power Supply System gives audio alarms when battery is low. On Line Uninterrupted Power Supply System is a Forced air cooled unit that adopts APWM technology with MOSFET or IGBT.