Pop wrote:
Matt Whiting wrote:

JTMcC wrote:


"Kathy" wrote in message
...


"JTMcC" wrote in message
...


"Tekkie" wrote in message
ual.net...


Lil' Dave posted for all of us....



had to have permanent meter loop installed vice a
temporary.
This provides
power to the water well pump (30 amp breaker two phase),
and a
120V

GCFI


outlet (20 amp one phase) for the home contractor subs.



There is no two phase power. Single or three phase.


There is such a thing as two phase, but it's pretty
uncommon
these days. I
believe it's still in use a few places back east. It used
to be
more

common,


in the early days of electrification.


There's a little 2-Phase left around Philly. Richmond,
Hunting
Park and Northeast Philly, that I know of. And there might
be some
left in Atlantic City. I have a 2 Phase motor out of an old
machine. It's cool.


And I, think, around Niagra Falls.

Yes, and going back to the OP, even thought it isn't common
usage,
the two 110V legs off a center tapped transformer really do
constitute a two-phase system. If these two legs weren't 180
out of
phase, you'd not be able to get both 110 and 220.

However, having said that, you will get funny looks if you
talk about
having two-phase power in your house, even though is
essentially what
you have.


Matt


A very minor point, I agree, and I also call it 2 phase, but it's
not. When you get on a board like this, there are people from
boths sides of the breaker panel, and thus the arguements come
about when someone who's actually worked with 1 2 or 3 (or even
more) phases, it sometimes throws them for a loop. Then there
are also the kind who just have to pop in and explain how wrong
everyone is, and how only they know the proper answer, but never
back up anything they say so they can get a good drifting of the
thread. I hope I'm not either, but, just having had a
conversation with my electricla inspector over some work I had
done and having my mind in that gutter, I mean, area, here's my
take on it:

Actually, it's not two phase by definition. It's "split phase",
derived from a single phase. The two "phases" of the same single
phase are simply applied to the wiring so that the sine wave in
each leg is 180 degrees out of phase with the other. If it comes
in as single phase, it's single phase no matter what you do to
it. Thus, the proper term is split phase.

So if I use a MG unit running on the single phase coming into my house
to create polyphase power you are saying it is still really single phase
since that is what it came into my house as? Polyphase can be created
from single phase and vice versa. This has been done for years in both
power systems and electronic systems.

Yes, the convention in the power industry is to call two-phase only that
which has two sinusoids separated by a phase angle of 90 degrees,
however, that is a definition used only by the power industry. Any time
two phases are present, it can rightfully be called "two phase" no
matter what the phase angle separation may be. Again, the power
industry refers to three phase only when the separation angle is 120
degrees (which gives no current in the neutral with a balanced load -
which has some advantages), however, the broader definition covers any
system with three distinct phases.


Matt