[Cialug] Slightly OT, .. UPSs

[L. V. Lammert]

On Mon, 24 Feb 2014, kristau wrote:

> I agree with Scott. It sounds like there is a non-battery issue here. Most
> enterprise UPS units will allow you to change out the batteries "live"
> without taking the units down.
>
That's what I found, but I cannot find any data on 'fail mode' - i.e. what
I need is the UPS to fail to LINE POWER, if possible.

> Correct me if I'm wrong, but I believe there are two basic types of UPS
> units:
> - Switching types which use mains power and have a very fast relay switch
> which flips to battery when mains goes down.
> - Pass through types which run off the battery 100% of the time, with mains
> power simply keeping the batteries topped off.
>
That used to be called "offline" and "online" - most "offline" UPSs went
out of favor many years ago as newer switching power supplies cannot
tolerate that transient power loss.

	Lee