Long-term (hours+) solution for power outage: PBX, lights, and computers

[Bruce Dawson]

Ted Roche wrote:

> On Aug 31, 2006, at 5:39 PM, Ben Scott wrote:
>
> You should have seen the one I used to manage onboard a submarine!
>
>> So regardless of whether you go with a generator, a large battery
>> plant, a flywheel, or a giant mutant hamster in a wheel, I think you
>> are going to face problems in the area of physical plant.
>
> There's definitely a TANSTAAFL aspect to this.

Well, we've actually thought of a variation of "giant mutant hamster in
a wheel" (GMHIAW). We've decided on a 55 KW generator, but we're not
happy with it and I'm still looking for more effective (and creative I'm
afraid) solutions for the long run. The problems with the GMHIAW is:

    * Waste disposal is a problem. There's only so much land to compost
      on. Fortunately, we're a farm and don't [yet] need to file a EIS
      (Environmental Impact Statement) on this.
    * Food is also a problem, but solvable. Grain is comparatively
      cheap. But add vet bills, farrier, a second wheel for use while
      cleaning/maintaining the first, ...
    * Maintenance labor was the major con on this. Changing the team 8
      times a day, tacking up, ... would take at least 1 person 24
      hours. Add vacation and bennies for this person, ...
    * A team of 2 GMH would only generate about 7KW, which isn't really
      enough for us (but probably fine for Ted's client).

BTW: Our GMH (giant mutant hamsters) come in the guise of draft horses.

And this defintely won't work for Ted's client - talk about major
infrastructure changes!

But if you're interested in our project, check out our webcam at the
house site, or email me off-line.

> The desktop UPSes and a full UPS are almost solutions to two different
> problems. The desktop UPSes are primarily line conditioners and for
> one minute or less blinks of power. The big battery is for long-term
> power outage.
>
>> So you're probably best off getting rid of the small UPSes and going
>> to one big solution.
>
> One concern there is that the power off one of these big boxes is ugly
> AC and may not be suitable for powering computers. I've heard no
> horror stories pro and con.
>
> I'm not really their IT guy as much as their lead developer. I was
> asked if I knew of a better solution. While the space is rented, I
> suspect the client might be there for a while, but infrastructural
> improvements might not be that welcomed.
>
> Their power distribution is wired in the walls, and their computers go
> right into outlets next to their fans and space heaters, loads you
> wouldn't want on the UPS. Short of rewiring the place with a special
> feed for computer power, I'm inclined to recommend they beef up their
> desktop UPSes for a half-dozen workstations. Maybe a couple of
> workstations with long-term use would be sufficient for them. But if
> they go the other way, I'll caution them to consider removing the
> desktop UPSes.

Well, we've found that putting largish UPSs on each system rather
economical - we end up replacing them about once every 3-5 years, so the
cheaper the better. However, we do size our UPS so that we have about 20
minutes to get the generator running.

But batteries are the biggest cost, and we've found good deals at that
batteries place on Elm St. in Manchester. If we had to pay APC their
replacement prices, we wouldn't be able to afford it.

I suspect the best route for your client (if its who I suspect it is),
is to spec "standard sized" line-interactive UPSs for the desktops, and
for him to just budget buying 1 or 2 extender packs a month until he has
enough for all the systems. The extender packs are hot-swappable, and in
a pinch you can swap in a set while charging a set off-site on a
generator (or someplace that has more reasonable power).

Careful though, a lot of the UPSs can't handle a lot of amp-hours when
it comes to charging. And its difficult getting the vendors to fess up
how many extender packs their units can support. (If they say "as many
as you want", tell them you want to talk to their engineer).

--Bruce