Why is residential wiring known as single phase?

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rattus

Senior Member
That's incorrect Rattus. The phase of -sin(wt) is (wt). You have used a mathematical operation to transform the phase to be shifted, and then deny that this is what you did.

Yes, the expression is mathematically correct, right up until the point you call it "Real". Then it becomes a false statement.

You keep insisting on saying this, but then instead of defending it or providing a reference yourself, you dodge the question by saying it is not important to the discussion.

Did I say real?

I repeat, equating trig expressions with an identity means that they are equal in every respect--including the phase of sinusoids. Can't be both.

Have you ever heard of such a thing before rbalex sprung it on us? If so give us a reference. rbalex won't or can't.
 

rattus

Senior Member
Rick, try this:

Plot sin(wt) and -sin(wt) over a period:

+sin(wt) starts at 0, the phase constant for +sin(wt)

-sin(wt) starts at PI, the phase constant for -sin(wt) and sin(wt + PI)

Both functions cannot carry the same phase constant.

Different phase constants, different phases, thats all.
 
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Besoeker

Senior Member
Location
UK
I have been trying to stay on target.

But, in post #1744, Mivey raises the issue of the phase relationship between the primary and secondaries of a 3-phase transformer. This goes along with how I have been saying that the two secondary reconnectable windings X1-X2 and X3-4, or two halves of a single center-tapped winding, have a relationship with each other and the primary winding H1-H2, based on the real physical construction of the actual transformer.
Yes. The resulting voltages have a relationship with each other.
That can be expressed mathematically and measured with instruments.
That doesn't make them in phase or the same phase.
 

rbalex

Moderator
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Location
Mission Viejo, CA
Occupation
Professional Electrical Engineer
For those who feel compelled to drag in the question of life, the universe and everything – the answer is 42. For those that feel their personal history or what they think they learned, or obscure and undocumented references to giants of the past should be the ultimate evidence of reality – I don’t care.

I have neither the inclination nor obligation to deal with anything but how phase as defined, NOT “in-phase”, is relevant to the question “Why is residential wiring known as single phase?
 

__dan

Senior Member
The single phase two winding transformer seconday, for illustration, the windings can be extended to infinity in both directions with taps at every winding. For every possible voltage measurement or sum or subtraction of measurements, the solutions always fall on a single line. The geometry of the line is a one dimensional coordinate system and this contains all possible solutions and readings from the above problem. The line is usually referred to as the X axis and measurements are displacement from the origin at x = 0.

There is no need to resort to describing the above solutions in a two dimensional coordinate system, usually referred to as x, y axis or radius, angle in polar coordinates, because there is no displacement or variation in the second dimension. The math reduces to one dimensional analytical solutions (algebra). The variance on the Y axis = 0 and the phase angle variance = 0 (there is none). For all possible solutions and combinations above, all solutions reside along the same line, measureable and describable as displacement along the X axis, with sign positive or negative, simple displacement.

There are no, zero, solutions that have a positive displacement in the Y axis, or, in polar coordinates, a phase rotation angle other than 0 or 180. The 180 deg angle is an artifact of moving from a one dimensional coordinate system that contains all solutions and measurements (a line), to a two dimensional polar coordinate system that has no displacement or variance in the unused second dimension.

This is an application of Occam's Razor, where the simpler of two descriptions is more desirable.

Claiming the above problem set has a solution with a variance or displacement in a second dimension is a false claim. Changing the sign from plus to minus while measuring displacement from the origin along a line (moving in one dimension) does not by itself merit a two dimensional convoluted and misapplied description. This work fails the test of usefulness, which is one of the four tests of the scientific method (Linus Pauling). By extrapolation, work which fails the test of usefulness is not science.

This is for the single iron core two winding transformer secondary with a resistive load (the OP's inquiry). All problems and solutions lay on a single line with a positive or negative displacement about the X axis or line. No problems or solutions lay off of a single line.

Certainly, for other electrical circuits proposed, second iron cores with phase displaced voltage sources, circuits with inductive or capacitive elements, two independent rotating generator sources, adjustable black boxes built to create exactly the effect that is claimed, the solutions to the problem set occur in a two dimensional coordinate system with variances or displacement on the Y axis or rotating phase angles. The two dimensional coordinate system is useful and necessary for describing these problems.

For the problem proposed in the OP of the last four threads, all solutions and descriptions of solutions lay in a one dimensional coordinate system, on a single line with a positive or negative displacement.

Claiming otherwise is the literal equal of saying in response to the question, 'go learn phasor math before you attempt the understanding of the problem that you seek'. It is arrogant and obfuscatory to the petitioner who seeks understanding but lacks training with phasor math. It is an irrelevant and "non" answer. In fact, the second phase angle (180 deg) is an artifact of the coordinate measuring system and not native to the problem or solution that is proposed. All solutions lay in a one dimensional paradigm of understanding. It is a short distance from arrogance and obfuscation to perceived insult. The one dimensional solution or description to the problem is not wrong.
 

mivey

Senior Member
If you are truly trying to answer the question, then why do you keep reverting to poly-phase systems, when this discussion is about a single-phase system?
It did not appear the one-transformer examples of a phase shift were sufficient in number to bring understanding so examples with multiple single-phase transformers were used.

The transformers in my open-wye are two single-phase transformers, plain and simple. Their use in a three phase system only illustrates that the windings are used to create phase shifts. Indeed, it illustrates that the windings of a single-phase transformer are used to provide voltages that are shifted in phase using different phase angles for each winding half.

Don't forget, a poly-phase system is also a group of single-phase systems.
 

mivey

Senior Member
For those that want to discuss phase using their personal history, or what they think they learned, and want to do so without valid references ? I don?t care.

I have neither the inclination nor obligation to deal with anything but how phase is defined and interpreted by our industry, universities, reference texts, textbooks, and other valid resources.
 

Rick Christopherson

Senior Member
It did not appear the one-transformer examples of a phase shift were sufficient in number to bring understanding so examples with multiple single-phase transformers were used.

The transformers in my open-wye are two single-phase transformers, plain and simple. Their use in a three phase system only illustrates that the windings are used to create phase shifts. Indeed, it illustrates that the windings of a single-phase transformer are used to provide voltages that are shifted in phase using different phase angles for each winding half.

Don't forget, a poly-phase system is also a group of single-phase systems.
One of the things I remember from my freshman year was an analysis of Richard Nixon's famous "Checkers Speech", about how he went on and on with a heartfelt story about his dog Checkers, before anyone even realized that he never actually answered the question that had been posed to him.

You didn't even attempt to address my example. You deflected the discussion with your own version of a checkers speech. How can you claim that there was insufficient number in the example without even addressing it at all?
 

mivey

Senior Member
You didn't even attempt to address my example. You deflected the discussion with your own version of a checkers speech. How can you claim that there was insufficient number in the example without even addressing it at all?

Your example was of a time shift. I said the transformers do not have a time shift and the phase shift is a result of the physical angle change produced by the transformers, not a time delay. This is about the third time I have addressed your example but you say I haven't. We can't move forward like that.

Why don't you discuss my response instead of just claiming I have not responded? It seems to me we can make better progress that way.

I believe your question about a phase shift vs. a time shift was addressed in my response in #1744. Instead of just saying no answer was provided, please read my post and tell me what parts of it and the references you agree or disagree with.

Apply your example to the transformers like my open-wye and the Scott-T and tell me if you think they do or do not exhibit a phase shift.
 
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Rick Christopherson

Senior Member
Your example was of a time shift. I said the transformer do not have a time shift and the phase shift is a result of the physical angle change produced by the transformers, not a time delay.
What physical change is there between the two halves of the secondary that can cause one to be physically out of phase with the other? Also, the follow-up question that you still failed to answer was, when can you have a phase shift that is not a time shift?
 

__dan

Senior Member
For those that want to discuss phase using their personal history, or what they think they learned, and want to do so without valid references ? I don?t care.

I have neither the inclination nor obligation to deal with anything but how phase is defined and interpreted by our industry, universities, reference texts, textbooks, and other valid resources.

Requiring the recitation of the specified dogma without concern for right or wrong is a condition very widespread in the genetic code of the population and known as "addiction to power".

Here is the valid reference. Watch the google videos where the 'prisoners' are paraded around blindfolded and naked by the 'guards'.

http://en.wikipedia.org/wiki/Stanford_prison_experiment

The guards and prisoners were separated by lottery from a homogeneous tested pool of Stanford University undergrads.

I will, of course, recite the specified dogma, for a fee.
 

mivey

Senior Member
What physical change is there between the two halves of the secondary that can cause one to be physically out of phase with the other? Also, the follow-up question that you still failed to answer was, when can you have a phase shift that is not a time shift?
I answered those questions in textual format and with the references provided. But I'll see about putting something together for you in a different format.
 

rattus

Senior Member
For those who feel compelled to drag in the question of life, the universe and everything ? the answer is 42. For those that feel their personal history or what they think they learned, or obscure and undocumented references to giants of the past should be the ultimate evidence of reality ? I don?t care.

I have neither the inclination nor obligation to deal with anything but how phase as defined, NOT ?in-phase?, is relevant to the question ?Why is residential wiring known as single phase??

One would think that if a position is posted, the poster is obligated to defend that position. On the other hand, if the poster realizes his position is untenable, he may choose to cut and run and live to cut and run another day.

It would be so easy to provide a reference--if one existed.
 

Rick Christopherson

Senior Member
One would think that if a position is posted, the poster is obligated to defend that position. On the other hand, if the poster realizes his position is untenable, he may choose to cut and run and live to cut and run another day.

It would be so easy to provide a reference--if one existed.
PotKettle.jpg
 

rattus

Senior Member
Rick, I had hoped for a valid reference. Guess not.

Do you really believe that the phase of a sinusoid shifted by PI is wt? One could interpret that to mean that a sine wave is in phase with its inverse, and we know that isn't true.
 

rattus

Senior Member
Requiring the recitation of the specified dogma without concern for right or wrong is a condition very widespread in the genetic code of the population and known as "addiction to power".

Here is the valid reference. Watch the google videos where the 'prisoners' are paraded around blindfolded and naked by the 'guards'.

http://en.wikipedia.org/wiki/Stanford_prison_experiment

The guards and prisoners were separated by lottery from a homogeneous tested pool of Stanford University undergrads.

I will, of course, recite the specified dogma, for a fee.

What did he say?
 

mivey

Senior Member
What physical change is there between the two halves of the secondary that can cause one to be physically out of phase with the other? Also, the follow-up question that you still failed to answer was, when can you have a phase shift that is not a time shift?
I answered those questions in textual format and with the references provided. But I'll see about putting something together for you in a different format.

Ok, the graphic below shows what I asked you to try. You will notice that the artifact on the primary does not shift in time for the secondary waveforms. I have a different artifact for each primary winding and you can see how it shows up on the secondary. No time shift. But the red, white and blue secondary voltages have 0?, 240?, and 120? voltages. The 120? voltage is the result of phase shifting other voltages but there is no time shift in the delay or advance sense. Only if we compare the peak times of the waves do we talk about a time shift for the artifacts.

OpenWyewithAnomalies.jpg



PS: Good night. The guineas have long been in bed and I should be too.
 
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