nanog mailing list archives

Re: Want to move to all 208V for server racks


From: Kevin Day <toasty () dragondata com>
Date: Thu, 2 Dec 2010 12:13:09 -0600


On Dec 2, 2010, at 12:08 PM, Ingo Flaschberger wrote:

For standard 110V service, you use a single-wide breaker and send one hot phase + neutral and you get 110V. The 
difference between two phases is 208 volts though, so you use a double wide breaker and can send to device without 
using a neutral wire. Just 2 hots and a ground. If that's all you're doing (you don't need legacy 110V service 
anywhere) you skip the ground wire going into the panel entirely.

that one looks dangerous.

Err, I meant "skip the neutral wire". It's still grounded. And there are normally significantly more covers over the 
panel than this, there were a dozen screws I had to remove to expose all of this. :)

This is a much smaller scale panel though, not far up from a typical home system. The more current you start talking 
about, the more isolated everything becomes until you wouldn't even be able to see the bus bars like in this one.

-- Kevin






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