On Tue, 20 Mar 2007 08:50:03 -0800, Joerg
wrote:
[snip]
In the US it is not very common to have three-phase available at the end
user. Part of our community does have a three-phase distribution at the
kilovolt level. Then they hang each transformer between two of the
phases. Pretty much in a statistical or round-robin scheme to provide a
somewhat equal load. The transformer secondary is a center tapped
120V+120V and typically feeds 3-5 houses.
Industry sometimes uses three-phase but I remember a case where a
business wanted to get that and the CEO almost fell off his chair when
he received the quote from the utility. Then they opted to buy the
diesel generators they had rented as a temporary power source. This is
what you get with monopoly situations I guess.
In the mid '60's I had a house in old-town Scottsdale (69th Place and
Oak) with 3-phase power. Makes for very efficient A/C compressors.
...Jim Thompson
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