This text aims at to exchange the importance of load that bureau（station） take at the correspondence profession and to city electricity the charged barbed wire net request of stable safety

for satisfying vari- ous correspondence equipments

other sensitives advanced instrument equipments and not the line strict request of load to supply voltage quality

introduced medium large UPS how to carry on make choice of purchase

from the UPS type

work way

have great capacity to small match

parameter function index sign

storage battery and the choice of capacity

go together with a linear choice

load with the external world and other factor etc. carried on to elaborate in detail.