An uninterruptible power supply (“UPS”) includes an input module having a plurality of inputs, and at least one jumper element configured to selectively couple at least one input of the plurality of inputs to at least one other input of the plurality of inputs. The plurality of inputs and the at least one jumper element may be constructed and arranged to selectively achieve the following configurations: single power feed, single phase input and single phase output; dual power feed, single phase input and single phase output; single power feed, three phase input and single phase output; dual power feed, three phase input and single phase output; single power feed, three phase input and three phase output; and dual power feed, three phase input and three phase output. Other embodiments and methods of selectively achieving multiple power configurations are also disclosed.