Changes in Power Supply Systems

Over the past twenty years there have been significant alterations to large UPS systems and similar changes have taken place on DC power systems for telecommunications. Both have electronic circuits to condition the power and batteries to supply the energy in the event of mains failure. In the early days it was generally the policy to back up the whole, building when a UPS was employed. The incoming supply was connected via the UPS which was normally housed in a special room located in the basement. The 48 volt power supplies for telecoms, were similarly located with large busbars to distribute the current which often involved thousands of amps. The batteries employed were wet cells which required special ventilation and regular maintenance.