Why is residential wiring known as single phase?

[mivey]

No, because I know the difference between a physical inversion and a mathematical phase shift. That is the question I put before you, Mivey, and Rattus. You have yet to even acknowledge it. Why is that?

I believe my response was that the physical inversion is not a shift in time but neither are any of the other transformer manipulations that result in a real physical difference in phase angles.

 

[mivey]

Not all of us E.E.'s are so insecure in our knowledge and abilities that we need to keep showing pictures of projects to make us look super smart.

I think the purpose was not to look super smart but to illustrate how super dumb it is to say that the results were not real and to illustrate that he really does understand how electricity works despite the super dumb insults hurled his way.

 

[jumper]

We? Would that include you and the pet turd in your pocket? This is a point that you appear to stand alone on.

Getting desperate again.......................?

 

[mivey]

This is a point that you appear to stand alone on.

I have stated that you are looking at the shift as a time shift and it is not. I proposed that you call it phase difference instead of a phase shift if that makes you happier.

If you want to call a phase shift a time shift then I will agree that it is not a phase shift.

 

[jumper]

Not all of us E.E.'s are so insecure in our knowledge and abilities that we need to keep showing pictures of projects to make us look super smart. Most of us actually refrain from such things, because we find it to be in poor taste. But then again, that is just most of us. I certainly don't speak for all E.E.'s.

I am seeing insecurity and it it is not Bes...................:roll:

 

[jumper]

I have stated that you are looking at the shift as a time shift and it is not. I proposed that you call it phase difference instead of a phase shift if that makes you happier.

If you want to call a phase shift a time shift then I will agree that it is not a phase shift.

I like displaced.

 

[mivey]

I like displaced.

Works for me.

 

[mivey]

I remember the string being rattus asking how you could drop a negative sign from one side of the equation without changing the other side. In other words, he called you on the fake math term you created called a "characteristic phase" that gave you a fake license to "resolve" a phase constant into nothing. I called you on the same thing. You wanted to claim that you had the correct interpretation of "phase" and "in phase" although I proved that our industry has a different interpretation.

A graphical tool I found this morning that demonstrates the industry's use of "phase" and "in phase" as opposed to the snake oil that rbalex is trying to sell.

http://www.acoustics.salford.ac.uk/feschools/waves/super.htm#phase

 

[gar]

120227-0831 EST

If you have had a course in number theory, then you will be familiar with the term "modulo N". Often times called "clock arithmetic". With sine waves we usually work with modulo 2*Pi or 360 or you could use 100 if you wanted to.

Consider a one handed clock labeled 0 thru 11 (modulo 12). On this clock is there any difference between 10:05 AM Sunday and 10:05 PM Tuesday, And then what is the difference to 4:05 PM on Saturday? Note the only possible whole numbers for hours are 0, 1, 2, 3, 4, thru 11. And for minutes only 0, 1, 2, ... 59.

.

 

[rattus]

Drivel:

Drivel:

Maybe my drivel is irrelevant because it proves Bob's drivel to be even more 'drivelous'??

That is, phasors are real aren't they? Or maybe they are imaginary? Either way my simple phasor diagram illustrates the obvious fact that Va and Vb or whatever you call them exhibit a phase displacement of PI radians. Then they can't be in phase can they??

 

[gar]

120227-0930 EST

To add to my post of 1490.

There is no way for you to determine whether two sine waves that are 180 degrees out-of-phase result from an electrical inversion (transformer), a time delay (different travel distance, a delay line for example), or mivey's two different generators (both shafts connected together) if these sources are inside a black box and you lack information on the interior contents of the box.

From an analysis perspective they are all the same.

.

 

[rattus]

In a split phase system there are 6 possible voltage measurements which can be made. As mivey has said, all of these voltages are 'real'. None are more real than the others. They can be measured at the panel, they can be measured at the transformer. One doesn't have to measure them at all, one doesn't have to risk getting splintered climbing the pole.

One is free to represent these voltages any way he wishes. I choose to represent them as phasors which are just complex numbers. I also choose the neutral as a reference because in so doing the phase angle indicates the phase displacement of the two waveforms.

Now I write the expressions for the fixed phasors, 120Vrms @ 0 and 120Vrms @ PI. I could write -120Vrms @ 0, but that is awkward and does not show the phase angle.

I have done all this without any concern for the real world connections. I know what they must be, therefore I believe they are. Nuf sed!

Furthermore, to answer the OP's question, we can certainly assume ideal situations. No need to bother with impure sinusoids, noise, loading, harmonics, energy flow, phase shift vs inversion, non-linear loads, unbalanced loads, skin effect, teeter-totters, etc., etc., etc.

Now we can say, "Although there are technically two phases present, we call it a single phase system because it is supplied from one phase of a three phase system--usually'. That's all folks.

 

[__dan]

120227-0930 EST

To add to my post of 1490.

There is no way for you to determine whether two sine waves that are 180 degrees out-of-phase result from an electrical inversion (transformer), a time delay (different travel distance, a delay line for example), or mivey's two different generators (both shafts connected together) if these sources are inside a black box and you lack information on the interior contents of the box.

From an analysis perspective they are all the same.

.

Hi Gar

Your reply is exactly why this topic has gone on for six months, four threads, and 2000+ posts.

The electrician has field condition, the job requirements and the present hardware. He wants to know how to hook "it" up and why, in this case the single phase source and two winding transformer secondary.

From an analysis perspective this is very different from two independent rotating generator sources or a black box of unknown contents. You would have to scrap the equipment in front of you and spend money to obtain a different underlying physical reality to yield a different set of existing conditions, change "a" for "b". The electrician has "a" box, knows exactly what is inside the box (two winding secondary), he wants to know what the contents do, the cause and effect of how things are hooked up. Saying the effect matters but not the cause is unacceptable to half of the posters in the thread and the majority of the audience.

Saying there is a phase shift to the average person can create FUD, fear, uncertainty, and doubt. The inquiry is focused on relieving this uncertainty, on having an understanding that gives confidence in knowing what is happening and why.

In this case the phase shift is caused by a reversal of the leads attached to the windings relative to the winding turn direction, and not by any other cause, like by magic. The reason the reversal of the leads is necessary to cause the phase shift is because the transformer natively does not cause the phase shift, it offers two windings that are exactly matched in winding turn direction and so their outputs are "in phase".

 

[rattus]

Hi Gar

Your reply is exactly why this topic has gone on for six months, four threads, and 2000+ posts.

The electrician has field condition, the job requirements and the present hardware. He wants to know how to hook "it" up and why, in this case the single phase source and two winding transformer secondary.

From an analysis perspective this is very different from two independent rotating generator sources or a black box of unknown contents. You would have to scrap the equipment in front of you and spend money to obtain a different underlying physical reality to yield a different set of existing conditions, change "a" for "b". The electrician has "a" box, knows exactly what is inside the box (two winding secondary), he wants to know what the contents do, the cause and effect of how things are hooked up. Saying the effect matters but not the cause is unacceptable to half of the posters in the thread and the majority of the audience.

Saying there is a phase shift to the average person can create FUD, fear, uncertainty, and doubt. The inquiry is focused on relieving this uncertainty, on having an understanding that gives confidence in knowing what is happening and why.

In this case the phase shift is caused by a reversal of the leads attached to the windings relative to the winding turn direction, and not by any other cause, like by magic. The reason the reversal of the leads is necessary to cause the phase shift is because the transformer natively does not cause the phase shift, it offers two windings that are exactly matched in winding turn direction and so their outputs are "in phase".

Well, I placed my leads where I wanted them in the first place, therefore I didn't have to reverse them.

 

[rbalex]

I knew I shouldn’t have allowed myself to be drawn into the “Oscilloscope Jungle.”

Where:

? Defending the Myth of the non-existent “Second-Phase “at all costs is a doctrine that verges on the cultic.

? The comprehension of reality is limited to instrument displays.

? The definition of phase is amorphous and runs anywhere from non-existent to fabricated to ambiguous to, at the very best, colloquial. If a member of the Tribe of the Holy Probe offers a valid definition, it must be replaced immediately or ignored.

? The linguistic skills of some members of the Tribe prevent them from recognizing characteristic is a properly applied adjective. So it’s not too surprising, that reading is done to mine for opportunities to deliberately misunderstand, rather than for comprehension.

? Mathematics is limited to the comprehension of the silliest member of the Tribe or, when validly applied by the outside world, it must be denied altogether; however, the world outside of the Jungle must contend with every extraneous branch of mathematics and mathematical terms, no matter how trivial or irrelevant, raised in defense of the Myth.

? If a member of the Tribe accidentally stumbles over the obvious, the priests of the Tribe must chant, “I didn’t say that and he didn’t either.”

? One member of the Tribe’s entire argument is that driving voltages can’t be “in phase” because the resultant currents aren’t “in-phase,” but they can’t see those same voltages and currents must have the same periods for being mesmerized by the Grand Tetons. They think Ohm’s Law is irrelevant during the cleavage and any other time the trace shows zero current (ponder that).

? Constantly misquoting others by making false assertions (“You are saying.”) rather than asking interrogatory questions (“Are you saying?”) and routinely attempting to redirect the discussion away from the OP's core question is acceptable as long as it deflects relevant inquiry and defends the Myth.

Responding to anyone that can’t or won’t set aside the instruments, climb out of the Jungle, and actually think from the perspective of an engineer rather than a pure pragmatist (“What I do works so I must be right!!!) is a waste of time. I’m leaving the Jungle again.

 

[rattus]

I knew I shouldn?t have allowed myself to be drawn into the ?Oscilloscope Jungle.?

Where:

? Defending the Myth of the non-existent ?Second-Phase ?at all costs is a doctrine that verges on the cultic.

? The comprehension of reality is limited to instrument displays.

? The definition of phase is amorphous and runs anywhere from non-existent to fabricated to ambiguous to, at the very best, colloquial. If a member of the Tribe of the Holy Probe offers a valid definition, it must be replaced immediately or ignored.

? The linguistic skills of some members of the Tribe prevent them from recognizing characteristic is a properly applied adjective. So it?s not too surprising, that reading is done to mine for opportunities to deliberately misunderstand, rather than for comprehension.

? Mathematics is limited to the comprehension of the silliest member of the Tribe or, when validly applied by the outside world, it must be denied altogether; however, the world outside of the Jungle must contend with every extraneous branch of mathematics and mathematical terms, no matter how trivial or irrelevant, raised in defense of the Myth.

? If a member of the Tribe accidentally stumbles over the obvious, the priests of the Tribe must chant, ?I didn?t say that and he didn?t either.?

? One member of the Tribe?s entire argument is that driving voltages can?t be ?in phase? because the resultant currents aren?t ?in-phase,? but they can?t see those same voltages and currents must have the same periods for being mesmerized by the Grand Tetons. They think Ohm?s Law is irrelevant during the cleavage and any other time the trace shows zero current (ponder that).

? Constantly misquoting others by making false assertions (?You are saying.?) rather than asking interrogatory questions (?Are you saying??) and routinely attempting to redirect the discussion away from the OP's core question is acceptable as long as it deflects relevant inquiry and defends the Myth.

Responding to anyone that can?t or won?t set aside the instruments, climb out of the Jungle, and actually think from the perspective of an engineer rather than a pure pragmatist (?What I do works so I must be right!!!) is a waste of time. I?m leaving the Jungle again.

Maybe you could at least tell me why my phasor diagram is irrelevant??

Or shall we assume that you are a bad wizard pulling strings and pushing buttons to create a smoke screen?

 

[Rick Christopherson]

Maybe you could at least tell me why my phasor diagram is irrelevant??

Or shall we assume that you are a bad wizard pulling strings and pushing buttons to create a smoke screen?

Because you refuse to acknowledge that it is a mathematical transformation, yet still continue to ascribe it to be real. What he said above is spot-on.

When you are compelled to limit this discussion to "Ideal" conditions, then you are speaking solely about mathematics. No one argues the mathematics. You falsely extend pure mathematics as though they are real-world.

 

[pfalcon]

In a split phase system there are 6 possible voltage measurements which can be made. As mivey has said, all of these voltages are 'real'. None are more real than the others. They can be measured at the panel, they can be measured at the transformer. One doesn't have to measure them at all, one doesn't have to risk getting splintered climbing the pole.

? Constantly misquoting others by making false assertions (?You are saying.?) rather than asking interrogatory questions (?Are you saying??) and routinely attempting to redirect the discussion away from the OP's core question is acceptable as long as it deflects relevant inquiry and defends the Myth.

Actually, I've been the one counting potential potential measurements though Mivey certainly affirmed they could be made. And every time Mivey states they're real we all just roll our eyes as no one has ever said differently.

One is free to represent these voltages any way he wishes. I choose to represent them as phasors which are just complex numbers. I also choose the neutral as a reference because in so doing the phase angle indicates the phase displacement of the two waveforms.

? The comprehension of reality is limited to instrument displays.

And a steadfast refusal to consider any other point of reference because any other point of reference would completely collapse the argument.

Now I write the expressions for the fixed phasors, 120Vrms @ 0 and 120Vrms @ PI. I could write -120Vrms @ 0, but that is awkward and does not show the phase angle.

? Defending the Myth of the non-existent ?Second-Phase ?at all costs is a doctrine that verges on the cultic.

Or in this case demonstrate that using a common reference frame for both voltage measurements makes that pesky second phase disappear.

I have done all this without any concern for the real world connections. I know what they must be, therefore I believe they are. Nuf sed!

? The comprehension of reality is limited to instrument displays.

When the conclusions don't correspond to reality, reality must be quickly disposed of in favor of an oscilloscope.

Furthermore, to answer the OP's question, we can certainly assume ideal situations. No need to bother with impure sinusoids, noise, loading, harmonics, energy flow, phase shift vs inversion, non-linear loads, unbalanced loads, skin effect, teeter-totters, etc., etc., etc.

? The comprehension of reality is limited to instrument displays.

Once again. That annoying reality that would prove things like: Two phase matched sources do not equal one single phase system with a center tap.

Now we can say, "Although there are technically two phases present, we call it a single phase system because it is supplied from one phase of a three phase system--usually'. That's all folks.

? Defending the Myth of the non-existent ?Second-Phase ?at all costs is a doctrine that verges on the cultic.

And now, because rattus has said so, it is, therefore let there be phases.

Responding to anyone that can?t or won?t set aside the instruments, climb out of the Jungle, and actually think from the perspective of an engineer rather than a pure pragmatist (?What I do works so I must be right!!!) is a waste of time. I?m leaving the Jungle again.

Welcome fellow defector. I left when Mivey insisted power flowed outside the copper while current flowed inside the copper.

 

[pfalcon]

Maybe you could at least tell me why my phasor diagram is irrelevant??
Or shall we assume that you are a bad wizard pulling strings and pushing buttons to create a smoke screen?

Because you refuse to acknowledge that it is a mathematical transformation, yet still continue to ascribe it to be real. What he said above is spot-on.
When you are compelled to limit this discussion to "Ideal" conditions, then you are speaking solely about mathematics. No one argues the mathematics. You falsely extend pure mathematics as though they are real-world.

Or maybe Rick, we could once again tell him that ... ... Nah. Join the light side Rick. Defect from this pointless debate.

 

[rbalex]

Maybe you could at least tell me why my phasor diagram is irrelevant??

Or shall we assume that you are a bad wizard pulling strings and pushing buttons to create a smoke screen?

As a courtesy to you: because your diagram isn't relevant to phase.

I will repeat for the last time: direction, polarity or whatever manner or order you decide to apply probes isn?t relevant to what phase is; nor is magnitude. By the definition you originally offered, the only relevant elements in the definition with respect to the OP are the period (P) of the voltage functions and the factional part of the period (t/P) as they advance through time. If the voltage periods start and end at the same time (which they damn well better for a single-phase transformer) then they must have the same fraction (t/P) at any time t in the period P; therefore, they have the same phase.

Phase: Phase is the fractional part of a period through which time or the associated time angle wt has advanced from an arbitrary reference
[Kerchner and Corcoran, Alternating-Current Circuits, Wiley, 1951]

Note the definition of phase says nothing of magnitude (amplitude) or sign (polarity).

READ THIS FOR COMPREHENSION. Don't be caught by the Grand Teton's seductive illusion.

Any response not relevant to the definition you provided as it applies to the OP will be ignored. That is, you don't get to replace the definition, from behind the curtains.