In the case of 277/480volt power, the problem is the same, the solution a bit different.
Taking the 277volt line and powering a 208volt UPS with it will cause the UPS to immediately start shedding the power. Yes the specs say it can take 189-294volts, but it is not designed to do this continuously.
Option 1 is to transform the entire load from 3phase 277/480volt down to 120/208. This is expensive and requires a 300lb transformer (assuming a 10kva ups). With the transformer, freight, and electrical work, this can cost over $3000.
Our recommendation, is to use a buck transformer and step down from 277 to 240volt. Since, you cant simply buck all the way down to 208volt, you need a 240volt UPS. This smaller transformer fits in a 3U rack cabinet and costs under $400. Call us for the exact price based on your size
Either way, these are much cheaper solutions than trying to buy a 480volt UPS.
Fun fact... go to the APC Selector by load and ask for a 5000va UPS with 277/480volt power, put in 10mins and 10% expansion... and the selector spits out a $99,600 UPS solution
