On Fri, 02 Feb 2007 20:41:33 -0500, wrote:

On Fri, 02 Feb 2007 15:13:46 -0600, Mark Lloyd
wrote:

. It is even weirder when you have a three phase delta system
with one side center-tapped and grounded. It is one of those unfortunately
ambigious situations where the language is sometimes not precise enough to
clearly describe the situation. People have been disagreeing and arguing
this point forever and probably will continue forever. It is not a
disagreement about the facts, but only "What is the nameof it?".

Don Young

Right.

I'd find that 3-phase delta system confusing too.


It is just a garden variety single phase 120/240 transformer that they
add a second one to and trick motors into thinking it is 3 phase.
Generally they don't use the 3d transformer to make a true delta.
If they wanted to spend that much money you would get 3p wye.
You see it in light industrial areas where most of the load is single
phase on a big 1p transformer and a second only supplies the "red" leg
for the 3p load. (actually identified orange) As long as you never put
L/N loads on the 208v red leg it works fine.

That reminds me that there's a lot about 3-phase systems that I don't
know.
--
Mark Lloyd
http://notstupid.laughingsquid.com

"Unlike biological evolution. 'intelligent design' is
not a genuine scientific theory and, therefore, has
no place in the curriculum of our nation's public
school classes." -- Ted Kennedy