Why is residential wiring known as single phase?

[ronaldrc]

Yea, looks like iwire was right!! only a few more to go...

But I can't help myself

 

[gar]

120209-2343 EST

rolandrc:

Is it clear to you that you can parallel two voltage sources that have the same amplitude and frequency, if the two are in phase (meaning zero phase difference between the two voltages)?

Then do you see that, if there is any shift between the two voltages that is not N * 360 there is some circulating current as a result of the phase shift and it is greatest at a shift of 180 deg?

.

 

[Sierrasparky]

120209-2343 EST

rolandrc:

Is it clear to you that you can parallel two voltage sources that have the same amplitude and frequency, if the two are in phase (meaning zero phase difference between the two voltages)?

Then do you see that, if there is any shift between the two voltages that is not N * 360 there is some circulating current as a result of the phase shift and it is greatest at a shift of 180 deg?

.

Interesting :?

 

[rattus]

And reversed polarity is not the same thing as shifting a sine wave in time.

Now Ronald, why do you say that? They are mathematically equivalent.

 

[Rick Christopherson]

Now Ronald, why do you say that? They are mathematically equivalent.

I assume he said it for the same reason I pointed it out, and the same reason why you have since dodged the discussion. No one is contesting that they are mathematically equivalent. However, you repeatedly state that they are exactly the same. You already acknowledged that they were not exactly the same earlier today.

How come you keep dodging my original question?

 

[Besoeker]

A 180 deg shift is not described as in phase.

.

Is for hexaphase which you get from three centre-tapped windings, an arrangement commonly used on low voltage high current rectifiers.

 

[gar]

120210-0648 EST

Besoeker:

A reference for the usage of 6 phase from the use of 3 center tapped transformers in a 3 phase system is:

"Theory and Application of Industrial Electronics", Cage and Bashe, McGraw-Hill, 1951. See page 10 for several rectifier connections, including six-phase half-wave using three center tapped secondaries.

.

 

[rattus]

Because they are exactly what was asked about.

.

Jim, can you elaborate a bit.

 

[jim dungar]

Jim, can you elaborate a bit.

I posted the original question and the follow up question.
What do you think is off topic?

 

[rattus]

I posted the original question and the follow up question.
What do you think is off topic?

Not off topic. Your one sentence reply doesn't answer the questions for me.

 

[jim dungar]

Not off topic. Your one sentence reply doesn't answer the questions for me.

Too bad. However, I am not going to guess at what you are questioning.

 

[K8MHZ]

Not off topic. Your one sentence reply doesn't answer the questions for me.

I think there are plenty of sentences in this thread with the intent of answering your question.

Iwire was right. 600 posts and no conclusion in sight!

Counting down......

 

[rattus]

I think there are plenty of sentences in this thread with the intent of answering your question.

None of them has convinced me that these arguments are germane to the original question.

 

[Mike McDonald]

Single or Multi-phase, 90, 120 or 180 out of phase

Single or Multi-phase, 90, 120 or 180 out of phase

Ok, maybe the question couldve been resolved way early if someone had posted a sine wave of the 120/240 supply voltage system being discussed. Eh? I think the UK guy did show a graph of a 168 p2p(170) volt 2 sine wave setup. What has anyone else shown? (I got bored with all the rhetoric around the 10th page, so apologies if there IS a graph between that and the 60th page.)

 

[jim dungar]

None of them has convinced me that these arguments are germane to the original question.

What do you think would be germane?

Have you followed the OP's participation in this thread?

 

[pfalcon]

It's just a simple question.
A simple answer would be fine.

Today, not often. Originally, high speed data collection of high frequency induction systems. Again. Questioning another posters credentials because you disagree with him is rude.

??? If that is true then how do you suppose we establish the phase relationships for three phase circuits where the coils are separate? I appreciate the effort but you've built the rest of the argument on a faulty foundation so you will have to try again a different way.

I don't propose establishing the phase relationships for a three-phase. That requires building a reference system far beyond this discussion. Describe the fundamental fault. It's not faulty just cause you disagree.

The one-sided use of the term sure makes it seem that way.
Then it appears you & I are just not in agreement on terminology. It would appear we agree on the physics.

We have enough problems with the basic terms of this discussion. How about we all, including myself, just give a little on nit-picking definitions. Infinitesmal differences in meaning don't resolve this topic.

Can anyone justify the argument that describing a waveform as either an inverse or being shifted 180 degrees is germane to the OP's question?
Can anyone explain why the fact that V1 and V2 are provided by a single transformer winding has anything to do with the OP's question.

V1, V2 being supplied by a single secondary winding means this is a single-phase circuit with a voltage divider at N.
If the windings were separate coils then it wouldn't be a voltage divider.

http://home.comcast.net/~ronaldrc/wsb/The_Edison_Neutral.html

Love the picture.

Now Ronald, why do you say that? They are mathematically equivalent.

Lots of things are mathematically equivalent but not physically equivalent.

I think there are plenty of sentences in this thread with the intent of answering your question.
Iwire was right. 600 posts and no conclusion in sight!
Counting down......

You've contributed about 25 just counting them haven't you? About 4%?

 

[rattus]

V1, V2 being supplied by a single secondary winding means this is a single-phase circuit with a voltage divider at N. If the windings were separate coils then it wouldn't be a voltage divider.

I would say that the 2nd leg doesn't function as a second phase. We cannot drive 2-phase loads with it. Therefore it is a single phase system. Doesn't matter where or how the waves were generated.

Lots of things are mathematically equivalent but not physically equivalent.

If V1 is described with a phase angle, that implies it is an ideal waveform. therefore -V1 = V2. Even if we do say V2 is apparently out of phase by 180 degrees. What does that matter?

 

[pfalcon]

I would say that the 2nd leg doesn't function as a second phase. We cannot drive 2-phase loads with it. Therefore it is a single phase system. Doesn't matter where or how the waves were generated.

Nice, simple, pragmatic answer to which I have no disagreements whatsoever.

 

[rbalex]

Nice, simple, pragmatic...

...irrelevant. It still doesn't answer the OP's question. Phase is not defiined by the type of load either.

 

[Rick Christopherson]

Even if we do say V2 is apparently out of phase by 180 degrees. What does that matter?

It matters because you have made the following statement many times over the years, but then sidestep the topic before it can be discussed.

.... then V1n and V2n are as Bes says antiphase. They don't just appear to be so, they are....

It's not nitpicking. You have repeatedly made a very specific statement that isn't true. In my opinion, it is the repetition of this statement that is one of the main reasons why so many of the other readers don't understand this topic. It is also one of the few (if not only) reasons why I engage in these discussions at all.

If you want to get rid of me, simply retract the statement, or at a minimum, at least engage in the topic without running away. If you want to defend it, that's fine. If you don't want to defend it, then stop saying it, please.