[rescue] SGI Challenge L systems available in Denver

Ethan O'Toole ethan at 757tech.net
Thu Sep 16 13:32:37 CDT 2004

> On Thu, Sep 16, 2004 at 01:14:45PM -0400, Ethan O'Toole wrote:
>> Probably 25 amps of computer stuff humming (Indys, Sparc 20s and AMD
>> Athlons at the time).
> That is a lot of Indys, Sparc20, and Athlons then.

That was a long time ago, I've since given away most of the Indys and
Sparc 20s.

> 1 Octane (SI+TRam, two disks that are rather hot)


> Probably a few other things I'm missing.
> There is other stuff that might be running, like perhaps a GC instead of
> the dreamcast, or perhaps an additional SS20 or Indy.
> I don't know how many amps I'm using, but it isn't tripping the 15amp
> breaker, nor for that matter the lesser overload protection in the first
> power strip that breaks out to other strips for all of these devices.  I
> keep wanting to buy a device to measure what's actually used by all of
> this.  I know that in the summer time, the electric bill for our
> apartment is about twice what the 4x larger 2nd and 3rd story apartment
> pays (and they use AC as well).  In the wintertime we pay about the same
> as anyone else.

You should be careful. When I was younger, still living with parents but
employed (and onsale.com was big) I picked up a number of systems.
Unfortunately my room was tied on the same outlet as the outlet in the
parents bathroom. Hair dryer! When I moved out, I guess the wiring cooled
down and the circuit "broke" ... I fixed it, but found the insulation /
wire nut caps had actually melted in the junction box! YIKES! Thre breaker
did trip once or twice, but be careful because breakers aren't as reliable
as their old counterparts... the fuse.

> When we buy a house, I plan to remodel the garage to be a machine room,
> and it will have a large sub panel, and I will break out the equipment
> to not use power strips so much.  I'm not really happy with the current
> arrangements, but it's what I'm stuck with for now.

I feel ya.

I recently picked up a very large UPS, so now am ?lucky? enough to have 60
amps x 3 phases going into the UPS, which then has a sub panel that feeds
into power boxes in racks. I still have yet to migrate all of the systems
over to the UPS. The other issue is the batteries for the UPS are almost 3
years old. At around 5 years old I will start to not trust them, and they
will probably have to be replaced. I priced them at about $100 each online
just picking a random site, and it uses... gulp... 60 of them. The thing
is, there are 3 cabinets each with 20, and you can run it on just one. So
if I had the $6000 to replace the batteries (which I don't), I would
probably to invest $4000 in a used generator set versus batteries. 20
batteries provides like 20 minutes of runtime at 8000 watts? With all 60
batteries, it can do 24,000 watts for 18 minutes! The UPS is actually
rated to supply three 100 amp legs, but since my service is only 100 amps
at the space I have it on a 60 amp breaker, the remaining power is used
for a few desktops and the HVAC.

I picked up off of eBay three 100:5 current transformers, and a thing
called a PowerLogic unit made by square D. We had them in the MGE PDU's at
NASA. So I recently hooked it all up, and I can tell what each leg is
pulling in terms of amps by looking at the powerlogic unit. It's pretty
slick, we plugged it into a portable generator and was able to see how
much THD the thing was pushing. Yikes. If you find a current transformer,
you should be able to use it to measure current draw. You run the hot wire
(black in the US) thru the round thing, then attach a meter to the two
terminals. It is an inductive device... similiar to the clamp on meters (a
split core current transformer is what they use).

When I get a chance I will shoot a picture or two of the UPS setup (once
the area is cleaned up a bit). It's pretty neat. A friend helped install
it all (He is an electrician and more familiar with the 3 phase stuff).
The UPS is an older model Exide that came from a local ISP. I've been
watching generators heavily but at the current time don't have the moolah.
I need something like a 60kw 3 phase Onan / Cat-Olympian / Generac /
Kohler diesel with switchgear (switchgear is fairly easy to get).

In time.

.--[Ethan O'Toole]-------------------------------+
: www.757tech.com  757 Technologies  (757)233-9460
: +    Hosting : Coloc : Networking : Security  +
: Wireless : Onsite services : Unix/Linux/Windows
`--------------------- - - - - - - - - - - - - - +

More information about the rescue mailing list