The Online UPS (Uninterruptible Power Supply) is a double-conversion power protection system designed to provide continuous, clean, and reliable AC power for sensitive and mission-critical equipment. Unlike offline or line-interactive UPS units, an Online UPS constantly converts incoming AC power to DC and then back to AC, fully isolating the load from all grid disturbances such as voltage fluctuations, surges, noise, and frequency variations. This ensures zero transfer time during power interruptions, making it ideal for environments where even a millisecond of power loss is unacceptable.