Liebert psi xr is a compact line interactive ups system designed especially for it applications such as network closets and small data centers the flexible design of liebert psi xr allows the unit to be configured as a self standing tower or to be rackmounted within a 2u space it is available in four capacities in both 230v or 120v models the ups features an innovative line interactive design incorporating buckboost automatic voltage regulation technology this protects against utility vol