Why is residential wiring known as single phase?

[Rick Christopherson]

And you are correct within the frame of reference through which you choose to look at it, which is not absolute. For the record, I never took one side or the other on this stupid non-issue. I have been following it strictly for entertainment value, which is wearing pretty thin.

Your assessment is spot-on. There are a few members that are trying so hard to force an opinion on everyone else, that they are falsely presenting opinion-based information as if it were absolute information. It's entertaining, from the perspective of observing just how far they will go with deceptions, but it also grows quite frustrating to sometimes have to address their dishonesty in debating techniques when they go to extremes. As I have said, it would be refreshing to have an honest debate on this topic.

 

[Besoeker]

Your assessment is spot-on. There are a few members that are trying so hard to force an opinion on everyone else,

I'm presenting facts based on experience.
I'm not forcing them on you.
Whether you accept them or not is your choice.

 

[Rick Christopherson]

I'm presenting facts based on experience.
I'm not forcing them on you.
Whether you accept them or not is your choice.

No, Beseoker. You are one of the worst offenders. Because it is not obvious whether you are being deliberate in your misinformation, or are ignorant to your misinformation. That makes it even worse.

You habitually make absolute statements regarding your examples that claim they do not function without a phase shift, but when you make these statements, you fail to provide the necessary conditions for which those statements are true. If these statements are inadvertent, then they are made out of ignorance of the systems. If they are deliberate, then they are blatant and intentional lies. Either way, I would not be very proud to be making them.

 

[Besoeker]

No, Beseoker. You are one of the worst offenders. Because it is not obvious whether you are being deliberate in your misinformation,

No misinformation whatsoever.
Bear in mid that I design this stuff.

 

[Rick Christopherson]

No misinformation whatsoever.
Bear in mid that I design this stuff.

You seem to think that we are so incompetent that we might be impressed with your pretty pictures and claims. Do you really believe that you are the only design engineer here? You keep making a point of this and showing pictures out of insecurity. Those engineers that are less insecure do not feel the need to remind everyone of our abilities constantly.

Yes, your postings are rife with misinformation. Your latest diagram stated the currents must be in phase with your chosen voltages, but since you failed to provide proper information with this statement, it is false. Given your propensity for doing the same, I will go out on a limb and call it a lie. Contrary to a voltage designation that requires 2-points to be identified, a current designation is absolute between nodes. It does not vary depending on your chosen frame of reference.

 

[Besoeker]

You seem to think that we are so incompetent that we might be impressed with your pretty pictures and claims./quote]
They were provided for information.
They are real.

 

[mivey]

As I have said, it would be refreshing to have an honest debate on this topic.

Rick claims he does not understand:

#1724: Rick
I don't understand where you can be coming up with this idea that a phase shift can exist without a time shift.

#1744: mivey
In my open-wye to 4-wire wye...both the X1->X2 = V@0? and X2->X1 = V@180? voltages have physical phase displacments that produce voltages with physical phase displacements.
...
I can provide more examples but you should get the concept by now.
...
Using the winding voltages in different ways does not produce a real time shift for t0 in one reference frame. But if we look at the positive peak times (tpeak) for those voltages, they do occur at different times.

#1809: Rick
I am still unclear about why you refer to these as "physical phase shifts".

#1827: mivey
Do you understand what I mean now?

#1829: Rick
No I do not.

Then Rick claims he never said he did not understand, but really does understand:

#2180: mivey
Since, according to you, you do not understand what I'm talking about, you have no basis for debating what I'm talking about.

#2182: Rick
I never said I didn't understand what you are talking about. Quite the contrary. I do understand it quite well.

#2200: Rick
It would be very refreshing to have an honest debate without games and deflections.


Rick says that transformer shifts are real shifts:

#1629: mivey
How would you classify the phase angle of the V@120? voltage produced in my open-wye example that comes from X2->X1+X6->X5?

#1630: Rick
That would be a real phase shift. No argument there.

Rick says that transformer shifts are not real shifts:

#1666: Besoeker
But nothing actually gets phase shifted. Wasn't that a point you made a while back to support your assertions?

#1667: Rick
In the example that I later realized he (Mivey) was referring to, there is both a physical (real) and apparent (mathematical) phase shift.

#2230: mivey
By "physical shift" I mean we physically take voltages from different terminals and in different directions in the windings.

2231: Rick
"And that is a physical inversion, by its definition, not a time shift or phase shift."

#2178: Rick
You are using a legitimate mathematical transformation, but then trying to defend it as though it was a physical transformation. Stick to your mathematical transformation and all would be fine.

Then Rick says that transformer shifts are real shifts:

#2289: mivey
"As for real: The phase shifts by inversion are just as real as the other transformer phase shifts. There is no difference from the delta-wye 30? or 210? shifts because they are not time shifts either. Same for the shift from the Scott, open-wye to 4-wire wye, and other connections.

For me to go along with your terminology, you would also have to denounce the other transformer shifts as being real phase shifts. In the past you have stated they were real shifts. I will never agree with you on that basis because it is not consistent."

#2306: Rick
"No, these are real phase shifts"

#2311: Rick
That's why I say it would be so refreshing to have an honest debate on this topic.

:roll:

 

[jim dungar]

This error is carried through the rest of the post so I won't bother to comment further.

The magnitude is V, so V+V=2V
The direction is an+nb=ab

I thought you would be able to understand these components of phasors (length and direction). But I guess you are so interested in finding something that does not prove a thought that is different than your opinion.

I prefer to write:

Vab = Van - Vbn = 240V

Because the phasor magnitude and phase are also the node voltage magnitude and phase.

Are you capable of subtraction?
Vab-Van = ????

 

[rattus]

The magnitude is V, so V+V=2V
The direction is an+nb=ab

Vab = 2Van = 2Vnb, true

But Van + Vnb = Vab NE 2Vab as you have written!

Vab is the voltage between nodes A & B= 240Vrms
2Vab is twice that voltage--480Vrms

That is a glaring error and a misuse of subscripts!

 

[jim dungar]

That is a glaring error and a misuse of subscripts!

Actually phasors would never have subscripts unless they were used to indicate direction, or to differentiate one voltage from another.
Phasors are magnitudes and angles. By normal convention phasors are shown with positive magnitude only, which is achieved by inverting the angle. However it is also a common practice to use a negative magnitude during intermediate calculations, saving the inversion to positive until the final step.

I could have said 2V@y? -V@x?=V@?? which would give you everything you need to construct the resulting phasor, regardless of the angle assigned to the direction 'ab'.
But, I was really trying to give you the option of choosing your own arbitrary angles for the directions of a to b and of a to n.

 

[rattus]

Actually phasors would never have subscripts unless they were used to indicate direction, or to differentiate one voltage from another.
Phasors are magnitudes and angles. By normal convention phasors are shown with positive magnitude only, which is achieved by inverting the angle. However it is also a common practice to use a negative magnitude during intermediate calculations, saving the inversion to positive until the final step.

I could have said 2V@y? -V@x?=V@?? which would give you everything you need to construct the resulting phasor, regardless of the angle assigned to the direction 'ab'.
But, I was really trying to give you the option of choosing your own arbitrary angles for the directions of a to b and of a to n.

I am appalled! You made a glaring error and don't even see it or won't admit it! The proper way to write it as a phasor is:

Vab = 240Vrms@0

Vab is the voltage on node A relative to node B of magnitude 240Vrms and phase angle 0.

 

[jim dungar]

I am appalled! You made a glaring error and don't even see it or won't admit it!

I am very well aware of the proper way to present phasors. I am also aware of how to write colloquially.

As I stated previously; when I asked my question I did not want to infringe your right to make an arbitrary assignment of the angles, nor of your choice of radians or degrees, so I supplied only the relative magnitudes and directions.

Could you provide the reference that says the voltage from node A relative to node B is phase angle 0?? Isn't some other angle possible, such as 180??

By the way the "rms" is infered, check any refence book on AC power system analysis.

 

[ggunn]

Only engineers could argue this vociferously and extendedly with such passion over an arcane point about which no one else in the world could give a <expletive, deleted>. Gotta love us!

============================================================

So, a lawyer, a priest, and an engineer are sentenced to die on the guillotine. The lawyer is led up to the device first. His head is placed on the block and the executioner pulls the rope, but nothing happens. The lawyer exclaims "To kill me now would be a case of double jeopardy. You cannot execute me!" The executioner reluctantly agrees and the lawyer is set free.

Next, the priest is brought up on the platform and put into place. Once more, the executioner pulls the rope and the blade does not come down. The priest cries out, "This is clearly a case of divine intervention. To execute me now would go against the will of God!" Again, the executioner relents and the priest is freed.

Next, the engineer is led up to the guillotine, but before he could be laid on the rack he looks up at the blade and exclaims, "Wait a minute! I think I see the problem..."

=============================================================

Lighten up, it's Friday!

 

[Besoeker]

Only engineers could argue this vociferously and extendedly with such passion over an arcane point about which no one else in the world could give a <expletive, deleted>. Gotta love us!

Two engineers, three opinions.

 

[pfalcon]

Obviously you are unfamiliar with static phasors, e.g.,

Van = 120Vrms @ 0
Vbn = 120Vrms @ PI

These are steady state values. They are NOT functions of time! RMS voltages are NOT functions of time.

See emphasis. Exactly why you can't understand this. Phase IS a time function. RMS is NOT. You can't determine phase by using non-time measurements. RMS inherently discards all phase angles. So correctly:
Van = 120Vrms <> 120Vrms @ 0
Vbn = 120Vrms <> 120Vrms @ PI
You can't use RMS with a phase angle. That's the whole point of RMS. To discard the phase angle to get an average.

These phasors are connected tail to tail at the neutral, just like the circuit. To get Vab you change signs and add--as in algebra. You just jumped the gun a bit. But the voltage on node B is still 120Vrms @ PI however you draw the phasors.

There is no neutral on a phasor diagram. Which is ONE of the many reasons you're drawing it wrong. Phasors are to be drawn stacked not off the origin which is a SECOND reason you're drawing it wrong. Mathematicians move them to the origin to save paper space but remember to do the math as placed when stacked. To get Vab you don't change the sign, you just add -- as in algebra. No algebraic operation allows arbitrary sign inversion which you're performing to make the equation work instead of using time-based measurements to create your phasors.

And the voltage at node B is either
120Vrms or -120V<0 @ 1/4 cycle or +120V<0 @ 3/4 cycle. RMS doesn't carry phase angle.

In fact, you would obtain Vab without drawing any phasors at all. Just do the subtraction,
Vab = Van - Vbn, phasorially that is.
Suggest you study up on static phasors.

Series voltages add. I suggest you study basic circuits and quit assigning an arbitrary PI phase shift to a phaseless RMS reading.

 

[rattus]

See emphasis. Exactly why you can't understand this. Phase IS a time function. RMS is NOT. You can't determine phase by using non-time measurements. RMS inherently discards all phase angles. So correctly:
Van = 120Vrms <> 120Vrms @ 0
Vbn = 120Vrms <> 120Vrms @ PI
You can't use RMS with a phase angle. That's the whole point of RMS. To discard the phase angle to get an average.


There is no neutral on a phasor diagram. Which is ONE of the many reasons you're drawing it wrong. Phasors are to be drawn stacked not off the origin which is a SECOND reason you're drawing it wrong. Mathematicians move them to the origin to save paper space but remember to do the math as placed when stacked. To get Vab you don't change the sign, you just add -- as in algebra. No algebraic operation allows arbitrary sign inversion which you're performing to make the equation work instead of using time-based measurements to create your phasors.

And the voltage at node B is either
120Vrms or -120V<0 @ 1/4 cycle or +120V<0 @ 3/4 cycle. RMS doesn't carry phase angle.


Series voltages add. I suggest you study basic circuits and quit assigning an arbitrary PI phase shift to a phaseless RMS reading.

If one doesn't know the difference between rotating and fixed phasors, one should not be criticizing those who do.

 

[gar]

120323-1104 EDT

pfalcon:

Phase is not a time function if you use the IEEE definition that has been referenced so many times above. From that definition phase is the fractional (non-dimensional) measurement of a position of some point in the period of a periodic function relative to a reference point in that period. This definition allows measurement over many periods modulo 1.

Although you may have waves that vary with time, the idea of phasors is to remove that time variation and relate the various signals relative to one another.

On the subject of RMS --- it is convenient and appropriate to use the RMS value as the magnitude of the phasor rather than the peak value of the waveform. Stout explains this on p 11 of his book on "Analysis of A-C Circuits".

Phasors for Y connected sources are usually drawn from a single point (call it neutral) because this provides a useful graphical view of the entire source circuit. From this layout it is easy to visually see a resultant phasor from the difference of two points.

.

 

[Rick Christopherson]

If one doesn't know the difference between rotating and fixed phasors, one should not be criticizing those who do.

Please enlighten us, oh Mystical One. Did your vectors become static simply because you drew them with ink? :lol:

 

[rattus]

pfalcon: The RMS value is the effective heating value of an AC voltage or current.

For example, 120Vrms across a resistor produces the same amount of heat as does 120Vdc.

120Vrms is a magnitude, always positive; tack on a phase angle and you have a static phasor.

BTW, I learned to subtract in elementary school.

 

[rattus]

Please enlighten us, oh Mystical One. Did your vectors become static simply because you drew them with ink? :lol:

If one doesn't know the difference between phasors and vectors, one should not 't criticize others.
who do!