I tend to answer a lot of questions about High Voltage systems (here, here, here) about its effects on UPS units.
Today, we had a customer that wanted 240v for his equipment and another customer that wanted to use his 5000va 208v UPS in his 240v building.
Both challenges can be solved with Buck Boost transformers. These affordable transformers step up and down voltage in a small frame by magic.
The customer that wanted 240volt for his equipment, bought one to plug in his wall and then plugged the 240volt UPS into it. Then the UPS output was 240volt as he wanted.(Type 3u)
The customer that had a 208v UPS, but had 240v building power, plugged in the magic unit (Type 5d) and reduced the voltage to the UPS and lived happily ever after.
We sell 4 common configurations, all are Plug & Play easy, and are sized to the UPS you are using. Notice, these units can only tweek the voltage, they are not full blown Step down 208v to 120v or Isolation transformers. We have those as well.