Rob> I am working on a brand new IT room for around 4 high (12kw?)
Rob> power racks and 2 wiring racks.  I was talking to the obvious
Rob> choice - Liebert - and they came back with a fairly eye watering
Rob> quote that made me question whether they are the only game in
Rob> town.  During my research I fell across two companies - Rittal
Rob> for cooling and Rittal's rebadge of Eaton technologies Powerware
Rob> line of UPSes.

Not sure about cooling alternatives, since we use Liebert at work I
can comment on them.

They suck in terms of consumables.  In the 5 years I've been here,
we've had to replace the dehumidifier bottles twice in each 10 ton
unit.  And it's not covered under our Maint contract.  Go figure.
Plus some other minor issues at times.  At least I can monitor them
(sorta) via SNMP.  Newer units will probably be better.

Now for large UPSes, you can also look at APC (http://www.apcc.com) or
Toshiba (http://www.tic.toshiba.com) also sells units here in the US.
I know because I've got a pair of Toshiba 4100 series in my server
room.  :] Again, the SNMP/Web interface on these 5+ year old units
isn't the best, but they've worked just fine.

The key with a UPS is to keep the loads balanced across them, and to
have an easy way (if possible) to move loads.  And if you can, run as
much of your gear a 240V instead of 120V as well.

Another issue you don't talk about is your runtime requirements.  The
amount of UPS needed to run your data center, *PLUS* the HVAC, is
going to be huge in terms of battery cabinets and numbers of
batteries.

Are you on the ground floor or not?  Have you made sure your floor is
strong enough for the loads you're going to be putting on them.  Those
four big racks could get quite heavy and be over the 100/200lbs /sq ft
that commercial buildings are designed for.  We had to have extra
steel installed for our serverand battery rooms.

We've also got a generator, so our UPS doesn't do HVAC at all, they
just die when the power goes out, and startup again (staggered by 1-2
minutes I think) once they get power again.  UPS is sized for < 20
minutes, because if the generator doesn't start and sync up in < 60
seconds, we're going to have a bad day no matter how much battery
capacity we have.

And yes, we made the cost tradeoff that the risk of having systems
crap out in strange cases is ok.  We actually ran into this problem
with our trandfer switch, which changed UPS power input from Street to
Generator.  Sometimes, not always, but sometimes (and always on
holidays when a damn rat would get fried in the bus bars on the
street...) one of the three phases wouldn't flip over.  UPS only sees
two out of three good phases, won't accept input, batteries die,
systems crash, alarms go off, etc.  No fun.

Now we do monthly tests of the transfer switch (after getting it
replaced and all kinds of other testing hassles outside of normal
hours and weren't they fun!) once a month, along with weekly generator
tests.

Rob> On the power side, the Eaton Powerware 9390
Rob> 
(http://powerquality.eaton.com/Products-services/Backup-Power-UPS/9390.aspx)
Rob> looks like a reasonable competitor to the Liebert NX UPS.  Beyond
Rob> that I have zero opinion on it.  It seems like a good tool to
Rob> beat Liebert over the head on pricing, but the reseller claims it
Rob> is more efficient/moderner/betterer so maybe it is worth taking
Rob> seriously.  Curious to know if anyone has nice things to say
Rob> about them.

In any case, in terms of HVAC units, make sure they specify in
*detail* what the lifetimes are of the dehumidifier bottles on the
Liebert units, and what's covered under your normal maint contract.  I
think they were around $1500 to replace each time, with T&M.  

Oh yeah, make sure you have nice clean water, or insist on filters
being installed on your AC units.  Include those into your maint
agreement as well.

Batters need to get tested every year and probably swapped every three
to four years as part of normal maint.  Yet another cost to think
about.

And get a generator if you can.  :]  Which of course costs in terms of
fuel and maint (oil changes, etc).  It's not cheap.  But cheaper than
lots and lots and lots of batteries, since our generator can run for
days if need be.

John
_______________________________________________
Discuss mailing list
[email protected]
http://lopsa.org/cgi-bin/mailman/listinfo/discuss
This list provided by the League of Professional System Administrators
 http://lopsa.org/

Reply via email to