[TriLUG] OT - number of circuits needed

[Matthew Pusateri]

Dell used to have a excel spreadsheet that would help, you could pick  
the number of each servers and it would calculate power and hvac.   
Looks like it is replaced with this: http://tinyurl.com/etqv2  The  
Dell tech specs tab does list the power supply wattage, which should  
be enough to guesstimate on.

Generally you only want to load a circuit to about 80% capacity.  With  
300 watt power supplies that works out to about 7-8 300 watt power  
supplies to a 20 amp circuit.   The formula for accurately doing this  
escapes me, maybe someone else will respond before I have time to  
google it.  But basically you want to figure out your power draw.   
Almost all manufacturer's will have this in the devices specs.

Matt P.


On Jul 16, 2008, at 11:53 AM, Glenn Hennessee wrote:

> I'm looking for some advice on how many 20 amp circuits would be  
> needed
> for the following scenario:
>
> 36 Dell Inspiron 530 computers
> 12 APC 800VA/540 watt UPS (3 530s per UPS)
>
> I  haven't been able to find anything on Dell's site as to how much
> power these systems consume. They are running without monitors so
> monitors don't figure into the power consumption. I'm sure the APC  
> units
> will also consume some power but I haven't been able to determine that
> at APCs web site. Right now all 36 computers (no UPS) are running on 3
> 20A circuits but it very close to tripping the circuit breakers. I'm
> assuming the APC units will draw power for their own use as well but  
> how
> much is the question. I would think that 6 total circuits with 2 UPS  
> and
> 6 PCs per circuit would suffice but could we get away with 4 total
> circuits with 3 UPS and 9 PCs per circuit?
>
> If anyone has some advice I would appreciate it.
>
> Thanks.
> glenn
>
> -- 
> Glenn Hennessee
> Department of Chemistry
> NC State University
> Raleigh, NC 27606
> Voice: (919) 515-2947 FAX: (919) 515-8909
> Email: Glenn_Hennessee at ncsu.edu
>
> -- 
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