text: strictly speaking - well, in fact, no strictly about it - kVA is not a measure of voltage, but the product of voltage potential and current amperage, much like wattage but taking power factor into account for non-resistive loads.
  
  you aren't going to find 50kV in a conventional street cabinet, methinks.  given my small flat has a 25A mains breaker, single phase, i could draw some 6kVA, while the building has several such flats.
  
  were electrical heating to be installed as planned, the draw would be much higher, and with the lack of insulation painfully obvious today, would be throwing money out the window for little benefit.  not sure what sort of power usages your cabinet feeds, but i just thought i'd digress before returning to my shocking experiences tracing wrongly-wired circuits, colour-coded for the colour-blind, but not protected against ignorance.
  
  whatever.  power, not voltage.