Andrew Partan writes:
In other words, its silly for them not to have UPSed AC available.
They do, its just that they are a telco & this is a telco facility they have *lots* more DC than AC.
Telcos have been around for 100 years; they know how to do DC; they do it quite well; you might as well use what they got instead of wasting time fighting for what is 'right'. Its not like its all that hard to get the gear that ISPs use to run off of DC.
I readily agree that if one has no choice one can get 48VDC equipment. The problem, as I see it, is that the overall cost of the facility providing battery backed up AC and people using standard mass produced equipment is substantially lower than the cost of the users all finding oddball power supplies and the facility providing DC. Furthermore, there is the issue of dramatically lowered convenience. Perhaps the telco folks don't have experience providing anything but 48VDC, but this really isn't rocket science. Besides, standby generators generally produce AC, and thats what one guesses one would have to go to if the area got hit by a hurricane or some such. Sure you can rectify AC, but again, why bother? Perry