Want to move to all 208V for server racks

William Herrin bill at herrin.us
Thu Dec 2 10:40:39 CST 2010

On Thu, Dec 2, 2010 at 11:22 AM, Ingo Flaschberger <if at xip.at> 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)
> you will need to check each device if it supports 240V, commonly the
> specified power ratings are printed at a stricker on the device itself.

Hi Ingo,

208 and 480 both at 60 hz are common three-phase voltages available in
commercial buildings in North America. 208 is three hot conductors 120
degrees out of phase with each other, each 120 volts to common. 480 is
the same but with 277 volts to common. 208 is often used with
higher-wattage computing equipment while 480 is usually used for
distribution on the input side of a large UPS and for lighting.

Another thought for you Jay - if you deliver L21 series receptacles to
the cabinet (5 wires) the customer can employ it as 120vac, 208vac or
a mix as they choose, though you will have to facilitate plug
converters for their PDUs. Also mixing on the same circuit complicates
amperage estimating something fierce unless the use at one of the
voltages is trivial.

Bill Herrin

William D. Herrin ................ herrin at dirtside.com  bill at herrin.us
3005 Crane Dr. ...................... Web: <http://bill.herrin.us/>
Falls Church, VA 22042-3004

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