Is there a tool for calculating the total electrical draw on a server room
based on typical equipment usage.
What's "typical equipment usage"? It'll depend on # of
servers, what they are exactly, what else is in the room
which is powered by same circuit.
You might not even want everything on one circuit because if
there were a problem with one systemcausing a short, you
wouldn't want the power to everything shutting off. A main
breaker for the room might be reasonable but still a further
breaker panel for individual circuits in that room is a good
idea - depending on scale of things.
Our electrician asked us what we needed? I dont want to go short.
thanks
CR
Probably not a tool that will have all the variables you
need, because there are so many different possible system
and PSU configurations possible, let alone all the
non-server electrical items that may or may not be in a
server room like monitors or A/C and ventilation, heaters,
etc... but you can still do it by hand.
For each system, estimate the amount of current it uses,
divided by 0.7 (70%) (assuming PSU is about that efficient),
then divided by about 0.75 if PSU is passive PFC or by 0.9
if active PFC type. Divide that total by the PSU input
voltage to arrive at current per system, then add up all the
individual currents per system to arrive at a total current
load, then add a margin like 50% (meaning double the current
capability of the wiring over what the expected load is.
For example a server using 200W with an APFC PSU running on
110V circuit would need about:
200 / (0.7 * 0.9 * 110) = 2.9 amps
If you had 4 identical systems then (4 * 2.9) / 50% = 23A,
but of course you need the current consumption of all other
equipment as well. Some things like a 60W light bulb are
easy to know, other things like and air conditioning unit
are not as easy as they have peak startup current, but a
large A/C unit or heater, anything with a medium or larger
moter, etc., ought to be on a separate circuit anyway and
the electrician should be able to figure out it's load on
his own since an A/C unit is a pretty common fixture.
