On Wednesday, November 27, 2013 12:10:11 PM UTC-5, Ed wrote:
On 11/27/2013 10:38 AM, TimR wrote:

On Wednesday, November 27, 2013 10:12:35 AM UTC-5, Ed wrote:

On 11/27/2013 09:06 AM, TimR wrote:



I asked the question about a multiple tap transformer because I don't understand the details about how a part of a circuit gets "out of phase."











It is not two phase, it is a single phase sin wave.





I think perhaps you did not read for comprehension.



I did not say it is two phase. I don't believe it is two phase. But clearly there is a phase relationship between part of the wire and another part, in that ON THE SAME WIRE some part of it is 180 degrees out of phase with another.





Put the reference clip of a dual-trace oscilloscope on L1.



Put the probe for Trace A on the neutral/center tap.



Put the probe for Trace B on L2.



Here's what you'll see:



The scope will display 2 traces in phase sync with each other.



The only difference between traces will be that Trace B will be twice the amplitude of Trace A

The only problem with that is the accepted reference point
for the system in question is the NEUTRAL/Ground. No one in
their right mind would reference the scope to one of the hot legs.

Don't believe me about two phases, ask the IEEE ppower engineers,
which is about as credible an authority on the subject as you can
get:

http://ieeexplore.ieee.org/xpl/artic...number=4520128

"Distribution engineers have treated the standard "singlephase" distribution transformer connection as single phase because from the primary side of the transformer these connections are single phase and in the case of standard rural distribution single phase line to ground. However, with the advent of detailed circuit modeling we are beginning to see distribution modeling and analysis being accomplished past the transformer to the secondary. Which now brings into focus the reality that standard 120/240 secondary systems are not single phase line to ground systems, instead they are three wire systems with two phases and one ground wires. Further, the standard 120/240 secondary is different from the two phase primary system in that the secondary phases are separated by 180 degrees instead of three phases separated by 120 degrees."


Or see the seperate discussion I started where I start out with
3 phase, and show what phases are, how you can morph that step by
step into split-phase using two of the three phases. It winds up
identical to a 240/120V split phase service and one of the phases
doesn't disappear.

BTW, still waiting for one of you alleged experts to define the term
"phase" for me.