Want to move to all 208V for server racks

Thu Dec 2 20:01:35 UTC 2010

On 12/02/2010 09:58 AM, Jay Nakamura 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.
> 

We run our datacenters with mostly 208V power because it lets us get
more power-hungry equipment in a single cabinet.  With the exception of
very old servers, pretty much all standard power supplies are
auto-sensing across the 110 - 240 range voltages and will work fine as
long as you use an IEC C13 to C14 cable.  Most of the older power
supplies have a manual switch you must switch if you don't want to blow
the power supply.

All network equipment that uses a standard IEC C13 cable that I've seen
is auto-sensing, but you should certainly check the documentation.  I've
seen recent and old Dell, Cisco, HP and Netgear switches that work fine
with 208V.

For anything with a AC adapter, we check the transformers and find most
of those are auto-sensing too.  The trick is either the customer has to
know in advance and pick up an AC adapter with a C14 connector (which is
fairly rare since they all use different polarization, voltage and
connector sizes), or to stock some NEMA 5-15 to C14 converters.

For a Cisco ASA, which we see a lot, you need a C5 cable.  The standard
cable is a C5 to NEMA 5-15.  We picked up some adapters from C5 to C14
standard pretty cheap to make these work.

It is very good practice to check EVERYTHING before plugging it in
because if it can't handle 208V, you will hear a pop and it will be dead
before you can realize your error.  Pretty much anything that uses power
has a label on it somewhere describing its supported input voltage.

-- 
Kevin Stange
Chief Technology Officer
Steadfast Networks
http://steadfast.net
Phone: 312-602-2689 ext. 203 | Fax: 312-602-2688 | Cell: 312-320-5867

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