Want to move to all 208V for server racks

Jameel Akari jakari at bithose.com
Thu Dec 2 10:35:34 CST 2010

On Thu, 2 Dec 2010, Ingo Flaschberger wrote:

>>  I really want to move all newly installed internal and customer racks
>>  over to all 208v power instead of 120v.  As far as I can remember, I
>>  can't remember any server/switch/router or any other equipment that
>>  didn't run on 208v AC.  (Other than you may need a different cable)
>>  Anyone have any experience where some oddball equipment that couldn't
>>  do 208v and regret going 208v?  We won't have any TDM or SONET
>>  equipment, all Ethernet switches, routers and servers.  I have control
>>  over internal equipment but sometimes customers surprises you.
> you mean 240V AC 50HZ and move from 120V 60Hz? (or also 50Hz)

Probably not; 208V AC here in the US comes from 3-phase distribution 
systems and is relatively common in datacenters, as well as other 
commerical and industrial settings.

What we've done is to install one 120V, 15A circuit per rack along with 
the 2x or 4x 208V 30A circuits.  There are too many oddball and/or just 
plain old devices out there to go totally without.  Like another commenter 
mentioned, the prime offender these days are devices with external power 
bricks or wall-warts; often times they only have NEMA 5-15 plugs so at 
least there won't be temptation to stick them in 208V receptacles.

Assuming you go with IEC C-13 or C-19 receptacles for those 208V circuits, 
that is.

Just be careful on older non-autosensing power supplies where you have to 
flip a switch to go from 100-120V to 200-240V input, in that you make sure 
to flip them to begin with, and that you flip them back should you ever 
mover them back to a 120V circuit.

Jameel Akari

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