which UPS? 1500VA are usually 900w but some of the more advanced go as high as 1050w. for 1500w of back up power, you need a 2000VA machine and that moves into requiring a 20A circuit.Just picked up a monster UPS from Amazon, since the puny little 900W models could not handle my workstation rig. Cyberpower PR1500LCD UPS, 1500W of juice, and around $700 too. Now I can run useless benchmarks with everything OCed without hearing my UPS scream BEEEEEEEEEEEEEEEEEEEEEEP!