Looking for advice on datacenter electrical/generator

["Dan Lockwood" <dlockwood () coe shastalink k12 ca us>]

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
 
Dan Lockwood
Microsoft Certified Professional
CompTIA Network+ Certified
Cisco Certified Network Associate