On-line UPS systems offer high performance power protection ideal for critical server and network equipment in datacenters, computer rooms and network closets. On-line, double-conversion uninterruptible power supply (UPS) maintains perfectly regulated output power by continuously converting raw AC input to DC, then re-converting output back to AC. Fully regulated sine wave AC output with +/-2% voltage regulation powers network equipment continuously, even during severe brownouts and overvoltages, all without depleting UPS battery reserves. Maintains battery-derived AC output during power failures with zero transfer time. Extended runtime options available. Interactive LCD interface reports UPS operating mode, detailed UPS and site-power data, plus enables a variety of UPS setup and configuration options. Highly efficient operation in optional economy mode saves BTU heat output and energy costs.