[tech] [committee] Auction TOMORROW for UPS

[Bob Adamson]

So, I managed to get a controller shelf and an expansion shelf for $220 
each. This is a little more than I wanted to pay, and a little more than 
the club approved, so Nick Bannon and myself have split the excess and 15% 
buyers premium between us. Thanks go to Nick - in an auction with over 600 
lots, it was great to have some company appear out of nowhere armed with 
lemonade :)

Harry McNally has offered to rewire the ?Malaysian? plug, and test the 
batteries, and Matt Didcoe has already got the ball rolling with quotes 
for an additional socket. Woo!

I also picked up a Canon 8800F scanner for a very good price, and have 
donated it to the club. Hopefully tracking things like receipts will be a 
bit easier now.

Regarding the aircon situation, maybe an extra *two* 15A sockets are in 
order, or perhaps it would be better to just amalgamate some machines. I 
think that deserves a new thread if someone has some ideas.

[BOB]


On Thu, 10 Mar 2011, Matt wrote:

> As I said in #committee this morning, I've been a strong advocate of
> UCC getting a UPS for some time - some people have however, raised
> very valid concerns.
> 
> While post sitting on this one would be nice, given I'm in two minds,
> I'm going to provide my approval for the purchase at this time on the
> proviso that the batteries aren't going to require immediate
> replacement (hopefully you can talk to someone at Ross' about that
> Bob).
> 
> I'll speak to Henry today about the procedure for getting a more
> formal quote out of FM for a 15A socket.
> 
> I'd like to thank those who have weighed in both here and on IRC - its
> good to see thorough discussion around the purchase :)
> 
> [MRD]
> 
> On Wed, Mar 9, 2011 at 11:53 PM, Duncan Sargeant <dunc+wheel at dunc.org> wrote:
> > 2011/3/9 Daniel Axtens <danielax at gmail.com>
> >>
> >> > For the UPS' sake, running only for 90 seconds doesn't take the battery
> >> > anywhere near to the UPS' "discharged battery" threshold which, for
> >> > these
> >> > small SLA batteries, kills them without too many cycles to flat. I
> >> > suspect the
> >> > UPS manufactures underrate the battery and are relying on the idea that
> >> > most
> >> > power losses are short.
> >>
> >> This is one of the best thought-out responses I've received to anything
> >> this year. Thanks Harry.
> >>
> >> I've also been told on IRC that we do have machines dying due to power
> >> issues, and that, to [BOB] at least, not having to rebuild his screen
> >> session is worth $1000.
> >
> > What are you guys trying to achieve?  Power conditioning, 2 min uptime, 30
> > min uptime, or longer?
> > A well-maintained UPS can be expensive to run.  The equation is something
> > like: purchase cost + electrical install + 2-yearly battery replace/dispose
> > + service costs.
> > OK, so you can skimp on the last two, but - and I'm hazy on this - dying
> > lead acid batteries will just suck charge continually while not actually
> > charging.  But if it is a (more expensive) double conversion UPS (AC-DC-AC),
> > it will make a nice, but warm, power conditioner.
> > I'd get a quote for the extra circuit, because it may not be trivial if they
> > don't have capacity upstream.
> > My experience with UPSs is that sometimes it is better to have multiple
> > small ones than one big one.  They are more disposable, and operating on
> > common 10A circuits makes the electrics much cheaper (you can also get
> > yourself into trouble with overloading easier, I guess).  Liebert is a good
> > brand but even their service guys warned me that like everyone, they make
> > crappy consumer models too.  One thing I would stay away from are modular
> > UPSs.  APC and Liebert make them where you can hotswap PSUs in and out - the
> > general wisdom is that the hardwired ones are more reliable (hotswap
> > batteries are fine).
> > I just specced and installed them for a while, hopefully this post will
> > attract comments from others more clued into electricals :)
> > ,dunc
>