Online UPS provides the highest level of protection possible. A double-conversion refers to converting the incoming AC power into DC power, and inverting it back to AC power. This ensures the newly reproduced power to be of a quality standard set by UPS, to be completely cleared of all imperfections of the power coming from the AC mains. Regardless of what is going on the AC mains side, the UPS output voltage, frequency and signal purity are kept up to the highest standards. The current flow is absolutely uninterruptible, the transfer time is zero. The UPS can work in pair with diesel generator, and can accommodate additional battery cabinets for a longer backup time.