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