[geeks] D'OH!

[Dave McGuire]

On February 1, David Cantrell wrote:
> >   15A and 20A are standard for houses in the US, more so 15A than 20A.
> > I have *never* seen a 30A 110V circuit in a residence.
> 
> Not even for electric cookers?  20A @ 110V only gives you 2kW, which is
> nothing.  Here IIRC electric cookers get a 30A circuit, for 6.5kW.

  If you mean what we call a "stove" or "range" in the states, those are
usually given 220V circuits.  It's common here (nearly exclusively so,
actually) for 220V to be brought into the breaker panel, and have
neutral in the middle, and one phase going down each side.  Going down
each column, the phases are reversed from breaker position to breaker
position, like this:

    --- hot1     hot2 ---
    --- hot2     hot1 ---
    --- hot1     hot2 ---
    --- hot2     hot1 ---
    --- hot1     hot2 ---
    --- hot2     hot1 ---

  ...with a neutral bus along the top, bottom, or side.

  In this way, a 110V circuit can come off of one breaker, or you can
put in a two-pole "ganged" breaker which connects to both "hot1" and
"hot2", giving you a two-phase 220V circuit for an air conditioner,
electric appliances, Cray, etc.  And if you populate it with 110V
circuits going down without skipping positions, you wind up evenly
distributing the load across the two phases.

          -Dave

-- 
Dave McGuire
St. Petersburg, FL         "Less talk.  More synthohol." --Lt. Worf