Looking for advice on datacenter electrical/generator

Thu Apr 3 00:25:34 UTC 2003

Just to give a working example, we currently have 2 redundant UPS's that 
typically will have over an hour runtime each (at current load) and an 
estimated 10 minute runtime each under a full load. Our generator and 
genset have us up on alternate power in approximately 10 seconds barring 
any odd problems with the generator, but a weekly exercise would typically 
identify a problem like this which can hopefully be corrected prior to 
needing the generator. A manual override of the transfer switch is possible 
if a failure should ever occur in that as well. HVAC is powered by the 
generator when it's running but not by UPS because of the tremendous draw 
it would have on the UPS's shortening battery runtime. 4 HVAC units usually 
keep it pretty cool, around or 60 degrees Fahrenheit so 10 seconds of all 
of them being off is not a problem. Even 10 minutes wouldn't raise the 
temperature all that much where it couldn't be cooled down rapidly when 
power is back online. Our currently fuel capacity (at current load) will 
allow us to run off generator for a few weeks without refueling. I'm sure 
this is all pretty standard for most people with similar setups. Hope this 
helps!

At 03:37 PM 4/2/2003 -0800, you wrote:

>Everyone,
>
>My organization is in a growth phase right now and within the next year 
>will find ourselves having outgrown our current 16KVa Symmetra.  We have 
>comissioned an electrical engineer to make a recommendation as to what is 
>required to install a new 130Kva Liebert nPower UPS along with a generator.
>
>Our current plan is to purchase the UPS with a minimal amount of battery, 
>approximately 15min worth; just enough to get the generator running.  Is 
>this the better way to go?  Or should we consider more battery?  What is 
>everyone's experience with the Liebert line of products?  Any kudos or 
>gripes?  Our electrical engineer also recommended that we purchase a 
>Generac generator and transfer switch.  Any experiences with that company?
>
>He also is strongly opposed to us purchasing a natural gas generator which 
>seemed like a shoe-in for us.  We have natual gas facilities and didn't 
>want to hassel with the diesel maintenance problems.  Is a natual gas 
>generator something that we should consider?
>
>Additionally he recommneded that we place the HVAC and lighting upstream 
>from the UPS and use some sort of junction box to supply both the UPS load 
>and the HVAC.  How do you "big guys" do it?  Here is a link to the diagram 
>that he gave us today.  Your thoughts are appreciated!
>
><http://www.shastalink.k12.ca.us/nanog/nanog.jpg>http://www.shastalink.k12.ca.us/nanog/nanog.jpg
>
>Dan Lockwood
>Microsoft Certified Professional
>CompTIA Network+ Certified
>Cisco Certified Network Associate
>

Vinny Abello
Network Engineer
Server Management
vinny at tellurian.com
(973)300-9211 x 125
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