Modular 3-phase intelligent, true on-line UPS system provides 100% system availability with N+1 modular architecture and 1+1 parallel capability. In N+1 configuration, it provides four self-contained, redundant 20kVA power modules that can be hot-swapped (with the load powered) if maintenance is required. In 1+1 configuration, two SU80KX models connected in parallel can provide fail-safe redundancy (two 80kVA models supporting 80kVA load) or increased capacity (two 80kVA models supporting 80kVA load) or increased capacity (two 80kVA models supporting 80kVA load). It provides mission-critical equipment with highest level of power protection available. Large capacity 80,000VA/64,000W UPS continually converts incoming AC power into filtered DC power and then resynthesizes it back into AC power with pure sine wave. Perfectly regulated, continuous sine wave output with zero transfer time assures compatibility with all equipment types. High input power factor, advanced IGBT inverter technology and digital signal processor (DSP) technology produce less than 3% input total harmonic distortion (THDi). With low THDi, generators run cooler and last longer, allowing managers to save installation costs by installing generator with capacity equal to the equipment load (1:1 ratio).