Why is residential wiring known as single phase?

[Rick Christopherson]

Rick can't explain how his nit-picking is germane the OP's question? Can anyone else explain it?

Actually, I did explain why it is significant in post 537.

The bigger question, is why do you keep sidestepping what I asked you earlier?

If it is so trivial, then why are you unwilling to retract it?

It's just one word. Why are you so unwilling to retract it if it is such a trivial word?

 

[pfalcon]

See, this post is exactly where I see Jim and you stumbling with each other.

I have no problem with your methodology and is one I use also. It is a tool just like the other method.

And I really don't believe Jim has any real problem with your methodology for the purposes you put forth.

What I take issue with is the position of some that one method deals with real voltages and the other deals with what "appears" to be voltages. The fact is that the voltages exist for both configurations and BOTH methods require that the user make an assumption about direction.

And here's a stumble. "Apparent" is a scientific term (borrowed from other disciplines) that means "Appears As" but never means "Is Not". It's used in most other scientific disciplines as a short way of saying "When measured under these specific conditions it yields these results." There's nothing fake or unreal about the apparent brightness of a star. Apparent brightness means "When measured from EARTH (a reference point) under these specific conditions (such as a brightness index) it yields these results (the apparent brightness)."

When we say your scope is seeing an "apparent voltage" it means your measurements are what they are but only under the specific conditions you've chosen. They'll be different values if the reference is changed.

Forget the word "phase" for a moment: Do you not agree that the forces available from X1/X2 and X3/X4 can be used as positive forces in different directions that produce results that occur at different times?

I agree. Emphasized just to make sure Mivey knows my feelings on this. I have absolutely no contentions on this point.

 

[jim dungar]

And that is an issue. There is not one "real" picture with all the other pictures being "fake" as the use of words like "appear" and "seem" indicate.

What other scientific words would you like to see used to describe multiple choices for a single item?
Given a black box with only two external leads, is it incorrect to say, "there appears to be a single voltage source in the box"? Which possible number of 'real sources' does my choice of words rule out?

And yes there is a real picture: two windings connected X2 to X3 are real, a load connected across terminals X1 and X2 is real, a second load connected x1 to x4 is real. The words used to 'verbalize' their connection are just that: words. While changing the words may make someone feel better in a 'kumbaya way', it does not change the actual connections.

 

[jim dungar]

...it means your measurements are what they are but only under the specific conditions you've chosen.They'll be different values if the reference is changed.

:thumbsup:

But this does beg the question: is there an 'actual' or is everything an 'appearance'?
To co-opt Descartes: "quodammodo ergo sum"?hmy:

 

[rbalex]

Group 1: 2 + 2 is 4 and the sky is blue
Group 2: NO! NO! NO! 2-(-2) is 4 and the grass is green
Group 3: No 2 + 2 is 4, but the sky is grey; it’s raining here.
Group 4: No 2-(-2) is 4; it’s raining here too and the grass is still green.
Group 5: The moon was 85% waning gibbous around 6am today and it will be again after it completes its next period in about 28 days.

 

[pfalcon]

Why? What does synchronize mean, but "at the same time."

For sinusoidal waveforms:
1) Establish a common reference frame for both waves to be tested.
2) Establish T=0; though not literally time it's usually refered to as Time equal Zero.
3) Establish the positive direction of measurement in reference to T, again not literally Time.

If, when measured in the positive direction, two waveforms have equal wavelength, cross zero simultaneously, and move in the same direction, then they are synchronous.

For the residential issue, only AB or BA presents a common reference (1). AN, BN, NB, NA exclude other portions of the coil that we wish to test. Therefore those references cannot establish synchronization or phase.

When using AB as the common reference (1), we can establish T=0 (2) as the point in time when the 240V waveform crosses zero and is rising. Part (3) is the one that's throwing everyone. The real thing we're measuring here is power transfer. Both voltage and current are measureable artifacts of power transfer. As we cross T=0 the power transfer is changing according to the voltage polarity; that is, it is increasing from A to B. To measure this we are applying physical leads in a physical direction. The physical order in which the leads are applied establishes (3).

If we presume that A is physically on our left with a red lead and B is physically on our right with a black lead; then we can compare any other segment of the secondary coil with the reference wave by applying the leads to either side of the section we wish to test BUT we must maintain the physical order of the leads: that is, the red lead must always be to the left of the black lead.

Therefore to establish whether the waveforms are synchronous we can compare AN or NB to AB. But comparing BN to AB violates (3) by reversing the direction of measurement. BN would be display positive voltage during negative power flow and negative voltage during positive power flow. Thus giving erroneous results.

 

[zbang]

Group 1: 2 + 2 is 4 and the sky is blue
Group 2: NO! NO! NO! 2-(-2) is 4 and the grass is green
Group 3: No 2 + 2 is 4, but the sky is grey; it?s raining here.
Group 4: No 2-(-2) is 4; it?s raining here too and the grass is still green.
Group 5: The moon was 85% waning gibbous around 6am today and it will be again after it completes its next period in about 28 days.

And the Denver Broncos are not in the Tour de France, either.

No matter how much, um, discussion folks have about what is a phase, where do you measure it, etc, as far as I can tell, we call it "single phase" because it that's the best name for it. It's certainly not "three phase", and by common usage of the term "two phase", it's not that, either. What's left to call it? Refer to iwire's post, #2. (I learned it as "split-phase" back in the 1970's.)

By the rate of posting, we'll hit 600 late today, I think.

 

[pfalcon]

:thumbsup:

But this does beg the question: is there an 'actual' or is everything an 'appearance'?
To co-opt Descartes: "quodammodo ergo sum"?hmy:

Literally it means, any time you measure something all you see is 'appearance' never 'actual'.

We know voltage is real but it's not really visible. So anything you see on a scope is appearance.

 

[pfalcon]

I would contend that measuring from Earth is not "backwards" but fairly standard. This measurement point would normally be associated with the center tap of the single-phase transformer. Positive voltage direction is an assumption we make, not something dictated by the materials, manufacturer labels, physics, etc.

Actually, since we don't back up from the Earth, it's like measuring from A or B, not the center tap. For "apparent brightness" it's like you can't reach the neutral.

 

[rbalex]

For sinusoidal waveforms:
1) Establish a common reference frame for both waves to be tested.
2) Establish T=0; though not literally time it's usually refered to as Time equal Zero.
3) Establish the positive direction of measurement in reference to T, again not literally Time.

If, when measured in the positive direction, two waveforms have equal wavelength, cross zero simultaneously, and move in the same direction, then they are synchronous.

For the residential issue, only AB or BA presents a common reference (1). AN, BN, NB, NA exclude other portions of the coil that we wish to test. Therefore those references cannot establish synchronization or phase.

When using AB as the common reference (1), we can establish T=0 (2) as the point in time when the 240V waveform crosses zero and is rising. Part (3) is the one that's throwing everyone. The real thing we're measuring here is power transfer. Both voltage and current are measureable artifacts of power transfer. As we cross T=0 the power transfer is changing according to the voltage polarity; that is, it is increasing from A to B. To measure this we are applying physical leads in a physical direction. The physical order in which the leads are applied establishes (3).

If we presume that A is physically on our left with a red lead and B is physically on our right with a black lead; then we can compare any other segment of the secondary coil with the reference wave by applying the leads to either side of the section we wish to test BUT we must maintain the physical order of the leads: that is, the red lead must always be to the left of the black lead.

Therefore to establish whether the waveforms are synchronous we can compare AN or NB to AB. But comparing BN to AB violates (3) by reversing the direction of measurement. BN would be display positive voltage during negative power flow and negative voltage during positive power flow. Thus giving erroneous results.

Yeah, So?

 

[rbalex]

Yeah, So?

Forgive me - that was just rude. As I understood your earlier comment, it seemed you were asserting magnitude was the only relevant element of synchronism as applied to the question under discussion.

 

[pfalcon]

Yes, I already know what to expect, and I know how to use a scope, and I understand the basics of transformers,

:thumbsup:

and I see no reason to move my reference point to demonstrate what I already know. That would be useless.

Which was my point. You already know but don't want to acknowledge what you see.

I know too that phase is sometimes loosely applied to L1 and L2.

Agreed, and typically applied in the loosest of fashions.

I know also that the fact that V1 and V2 are taken from a common winding is irrelevant.

:rotflmao:
Literally the most important fact of this discussion is that V1 and V2 are from a common winding.

I know that phase angles only apply to the fundamental frequency of a wave, therefore an inversion is tantamount to a phase shift.

Pragmatically correct, technically nonsense.

Anything else I should know? Oh yes, the ubiquitous residential service is single phase.

:thumbsup:

 

[Besoeker]

For sinusoidal waveforms:
1) Establish a common reference frame for both waves to be tested.
2) Establish T=0; though not literally time it's usually refered to as Time equal Zero.
3) Establish the positive direction of measurement in reference to T, again not literally Time.

If, when measured in the positive direction, two waveforms have equal wavelength, cross zero simultaneously, and move in the same direction, then they are synchronous.

Which, as has been demonstrated, is NOT the case for AN and BN.

For the residential issue, only AB or BA presents a common reference.

So which is common? B or A?

AN, BN, NB, NA exclude other portions of the coil that we wish to test.

You have included both halves in both directions. So maybe you could now explain what exactly has been missed?

 

[pfalcon]

Group 1: 2 + 2 is 4 and the sky is blue
Group 2: NO! NO! NO! 2-(-2) is 4 and the grass is green
Group 3: No 2 + 2 is 4, but the sky is grey; it?s raining here.
Group 4: No 2-(-2) is 4; it?s raining here too and the grass is still green.
Group 5: The moon was 85% waning gibbous around 6am today and it will be again after it completes its next period in about 28 days.

Group 12: 2+2=4; 2-(-2)=4; There is no sky, you're just staring at the wavelengths that made it through the atmosphere, but hey, if it makes you happy then it's blue.

 

[pfalcon]

Yeah, So?

If, when measured in the positive direction, two waveforms have equal wavelength, cross zero simultaneously, and move in the same direction, then they are synchronous.

As in magnitude is not considered for synchronous.

 

[Besoeker]

Literally it means, any time you measure something all you see is 'appearance' never 'actual'.

We know voltage is real but it's not really visible. So anything you see on a scope is appearance.

How often do you use a scope?
And for what?

 

[pfalcon]

CFor sinusoidal waveforms:
1) Establish a common reference frame for both waves to be tested.
2) Establish T=0; though not literally time it's usually refered to as Time equal Zero.
3) Establish the positive direction of measurement in reference to T, again not literally Time.

If, when measured in the positive direction, two waveforms have equal wavelength, cross zero simultaneously, and move in the same direction, then they are synchronous.

Which, as has been demonstrated, is NOT the case for AN and BN.


So which is common? B or A?

AN, BN, NB, NA exclude other portions of the coil that we wish to test. [

You have included both halves in both directions. So maybe you could now explain what exactly has been missed?

I'm pretty sure your post could use some editing but here goes if I follow it right:

So which is common? B or A? :: Neither. A and B establish the outer limits of the reference frame.
... what exactly has been missed? :: To pick one as an example: AN cannot be used for the reference frame because point B exists outside that frame.

 

[pfalcon]

How often do you use a scope?
And for what?

Now that's just plain rude. And you really aren't complaining about my scope talents but about that word "Apparent" again. As far as I'm concerned you should just go back to post 546 and not worry about "appearances" since they trouble you so much.

 

[Besoeker]

Now that's just plain rude.

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

 

[rbalex]

If, when measured in the positive direction, two waveforms have equal wavelength, cross zero simultaneously, and move in the same direction, then they are synchronous.

As in magnitude is not considered for synchronous.

I would say they were in phase, although most of the criteria except wavelentgh and, to some extent, zero crossing are irrelevant.

I seriously doubt you or anyone else would consider two generators being synchronized if they were"... measured in the positive direction, [having] two waveforms have[ing] equal wavelength, cross[ing] zero simultaneously, and move[ing] in the same direction, [but with different magnitudes.]"