"They all suck!" Re: UPS failure modes (was: fire at NAC)

Speaking on Deep Background, the Press Secretary whispered:

> The most annoying thing about UPSes is they fail at
> exactly the time they are needed most.

....Like tape drives..

ok, what UPSes do telcos use (besides their monster battery arrays)


They eschew same. Telco stuph runs on that -48v. It's their steak
& potato...err E.

But the price is high and not just the cost. A telco string stores
enough to qualify as weapons of mis destruction. Drop a wrench
and learn Braille. You need a PE with a track record in battery
plant design. You need a separate room, separate ventilation,
separate entrance, etc.

But your MTBF is many years. Yes, you lose individual loads,
but the string carries on. Provided, of course, you keep the
rectifiers running, and know when they fail...and fix same. (ATT
NYC Toll switch and DACS...)