Tripp Lite's SU20K3/3XR5 20kVA SmartOnline 3-Phase Intelligent, True On-Line Extended Runtime UPS System has been redesigned to save valuable space and simplify runtime scalability. Power and battery components are combined into a single, small-footprint module (the smallest in its class). A robust internal battery runtime capability can be easily extended by installing additional optional internal battery packs through the convenient front panel access door. The SU20K3/3XR5 features a large internal battery compartment that contains more internal batteries than the equivalent standard-run model (SU20K3/3) and more space to add additional optional internal battery packs to extend runtime.The SU20K3/3XR5 provides mission-critical equipment with the highest level of power protection available. Large capacity 20,000VA/16,000 watt UPS continually converts incoming AC power into filtered DC power, and then resynthesizes it back into AC power with a pure sine wave. Perfectly regulated, continuous sine wave output with zero transfer time offers compatibility with all equipment types. IGBT inverter technology produces output power with <3% THD (total harmonic distortion), allowing connected equipment to perform at its peak. A 3:1 crest factor safely supports a variety of equipment, even those with wildly-fluctuating power demands. Extremely efficient