Why is residential wiring known as single phase?

[mivey]

How will you measure it?

Why do you ask? There are many ways. A phase angle meter would be one way.

 

[T.M.Haja Sahib]

Why do you ask? There are many ways. A phase angle meter would be one way.

With a phase angle meter,measure phase angle differences for all loads connected across 120v/240v supply in a typical home,say yours,taking two voltages across two loads at a time.You will find zero phase angle phase difference in all cases.What does it mean?

 

[T.M.Haja Sahib]

If you take a single supply of just 120V it is just a single supply of 120V, Reversing how you measure it doesn't reverse its phasing.

Then how do you think Lissajous figures for 0 degree phase difference and 180 degree phase difference for two sine waves are obtained?

 

[mivey]

With a phase angle meter,measure phase angle differences for all loads connected across 120v/240v supply in a typical home,say yours,taking two voltages across two loads at a time.

Easy enough.

You will find zero phase angle phase difference in all cases.

No, you will not.

What does it mean?

Not real sure if you are asking a real or rhetorical question but:

If you find a zero difference then the phase angle is zero. If you find it is not zero then the difference is the angle indicated and means the waveforms are not in phase.

Not real sure why you just do not state what you have to say instead of asking questions with obvious answers. Why ask questions like this?:

First you please check the continuity between the grounds of two probes connected to the scope in the X-Y mode.Does the continuity exist?

Kind of like asking if the power was on when he was using his scope. I really don't see the point.

 

[mivey]

Then how do you think Lissajous figures for 0 degree phase difference and 180 degree phase difference for two sine waves are obtained?

I'm not sure where you are going but there is a difference in having one voltage and having two voltages.

A two-wire circuit can only be a single-phase circuit. To have more than one phase, you need more than two wires (i.e. you need more than one voltage or current).

 

[T.M.Haja Sahib]

No, you will not.

Please provide solid evidence.

Not real sure why you just do not state what you have to say instead of asking questions with obvious answers. Why ask questions like this?:

Because you miss the obvious such as in a 120V/240V supply all load voltages in a home are in phase and so the 120V/240V supply to a home is called single phase supply and like that.

 

[mivey]

Please provide solid evidence.

Any number of prior posts have already done that. But excluding the phases of the currents, and excluding the phase shift due to source impedance differences, at the very least you have this in post #847.

Because you miss the obvious such as in a 120V/240V supply all load voltages in a home are in phase

That's what we are debating. I say the view of some of them being "in phase" is muddied by definitions and preferences.

and so the 120V/240V supply to a home is called single phase supply and like that.

It is called that because the loads are normally all single-phase and the transformer is a single-phase transformer.

"All loads are single-phase" does not necessarily equate to "All loads are in phase"

 

[T.M.Haja Sahib]

Any number of prior posts have already done that. But excluding the phases of the currents, and excluding the phase shift due to source impedance differences, at the very least you have this in post #847.

I requested you for a solid evidence such as two loads in a home,one fed by 120V voltage and another by -120V voltage.You need to find it through your phase angle meter in your hand and identify that two loads.But you are presenting me with some imaginary construct.What is the problem?

That's what we are debating. I say the view of some of them being "in phase" is muddied by definitions and preferences.

To put an end to your debate,I requested you to ascertain the phase difference across all loads in a home using a suitable meter such as a phase angle meter.

"All loads are single-phase" does not necessarily equate to "All loads are in phase"

But it equates to all single phase load voltages in 120V/240V supply are in phase as can be readily measured by a phase angle meter,for example.

 

[T.M.Haja Sahib]

I'm not sure where you are going but there is a difference in having one voltage and having two voltages.

A two-wire circuit can only be a single-phase circuit. To have more than one phase, you need more than two wires (i.e. you need more than one voltage or current).

Take an oscilloscope in X-Y mode and with the individual grounds of its each probe separated in the scope i.e its two sets of deflector plates are separate.Apply 120v single phase supply to X-Y plates through two sets of leads.You may get a Lissajous figure in the scope.Reversing any two leads connected to X or Y plates will change the Lissajous figure in the scope.Won't it?

 

[Besoeker]

Take an oscilloscope in X-Y mode and with the individual grounds of its each probe separated in the scope i.e its two sets of deflector plates are separate.

Don't use a scope very often, do you?

Apply 120v single phase supply to X-Y plates through two sets of leads.You may get a Lissajous figure in the scope.Reversing any two leads connected to X or Y plates will change the Lissajous figure in the scope.Won't it?

That's equivalent to taking a 1.5V battery and measuring the voltage across it, first with the red lead connected to the positive then with the black lead connected to the positive then concluding that the humble C cell has two different voltages because the meter gave you two different readings. It's nonsense.

 

[T.M.Haja Sahib]

That's equivalent to taking a 1.5V battery and measuring the voltage across it, first with the red lead connected to the positive then with the black lead connected to the positive then concluding that the humble C cell has two different voltages because the meter gave you two different readings. It's nonsense.

With due respect,you do not understand the difference between a DC voltage and AC voltage.

 

[Besoeker]

With due respect,you do not understand the difference between a DC voltage and AC voltage.

Then I couldn't possibly know how to make controlled rectifiers at 40,000Adc configured as 24-pulse systems.
But I do.
I design, manufacture, test, and commission them.
And variable speed DC drives, inverters, DC choppers, sub-synchronous converter cascades.
Oh yes. And all the electronic controls needed to go with them.

Not too bad for someone who is ignorant about the difference between direct current and alternating current.
Maybe I'll put my abysmal ignorance into practice for a few years yet.

 

[rattus]

Here's one from a site where we are currently undertaking an upgrade.

Its days are numbered.....

State of the art!

 

[mivey]

I requested you for a solid evidence such as two loads in a home,one fed by 120V voltage and another by -120V voltage.You need to find it through your phase angle meter in your hand and identify that two loads.But you are presenting me with some imaginary construct.What is the problem?

Here is an idea: How about you do your own lab work? I want you to build what I have show in my graphic and prove that it is not so. Hop to it Cassidy.

To put an end to your debate,I requested you to ascertain the phase difference across all loads in a home using a suitable meter such as a phase angle meter.

I have done so countless times. since you have a tendancy to not believe what other people measure, I want you to do your own lab work.

But it equates to all single phase load voltages in 120V/240V supply are in phase as can be readily measured by a phase angle meter,for example.

Had you been able to follow what I posted, you would see that you can measure voltages with a 0? displacement and you can also measure voltages with a 180? displacement. Get to your lab now and find out for yourself.

Take an oscilloscope in X-Y mode and with the individual grounds of its each probe separated in the scope i.e its two sets of deflector plates are separate.Apply 120v single phase supply to X-Y plates through two sets of leads.You may get a Lissajous figure in the scope.Reversing any two leads connected to X or Y plates will change the Lissajous figure in the scope.Won't it?

Why don't you do your own lab work and let us know how this works out for you.

 

[mivey]

With due respect,you do not understand the difference between a DC voltage and AC voltage.

:roll:

 

[rattus]

Here's one from a site where we are currently undertaking an upgrade.

Its days are numbered.....

State of the art!

 

[jim dungar]

There is certainly resistance to saying that two voltages can have a real physical 180? phase displacement when present across two series windings.

The "maximum positve value" is the sticking point.

Viewed from the right side of my graphic, that reference frame would say that the positive peaks of both waveforms occur in the same direction at the same time. Their negatives work in synch in the opposite direction 180? later.

Viewed from the left side of my graphic, that reference frame says the positive peak of one waveform is working in synch with the negative peak of the second waveform. They also work together in the opposite manner at a point 180? later.

As my graphic shows, the voltages map to the same physical space and the only thing that makes a difference is the reference frame we choose. Both reference frames are valid and both voltage sets actually exist as can be seen by the voltages across the load in my graphic.

In other words, the voltage is relative and there is no universal reference.[/QUOTE]

Again nothing but how they appear based on how they are measured.

You are still discussing models not the real world.
Physically connecting two windings, on a common core, in a X1->X2+X3->x4 series arrangement is not the same as physically connecting them in a X1->X2+X4->X3 arrangement.
Physically connecting them in a X1+X3->X2+X4 parallel arrangement is not same as a X1+X4->X2+X3 arrangement.

 

[mivey]

Again nothing but how they appear based on how they are measured.

Everything we are discussing is about how they appear.

You are still discussing models not the real world.

Do you take issue with the model I have in my graphic? Are you saying this it is not a physically-realizable model?

Physically connecting two windings, on a common core, in a X1->X2+X3->x4 series arrangement is not the same as physically connecting them in a X1->X2+X4->X3 arrangement.

Never said it was.

Physically connecting them in a X1+X3->X2+X4 parallel arrangement is not same as a X1+X4->X2+X3 arrangement.

Never said it was.

 

[Besoeker]

You are still discussing models not the real world.

The oscilloscope pictures I posted were real world pictures.
For both the YT and XY modes.

Physically connecting two windings, on a common core, in a X1->X2+X3->x4 series arrangement is not the same as physically connecting them in a X1->X2+X4->X3 arrangement.
Physically connecting them in a X1+X3->X2+X4 parallel arrangement is not same as a X1+X4->X2+X3 arrangement.

I don't think anyone would dispute that. But connecting them in a X1+X3->X2+X4 parallel arrangement wouldn't give you 240V.
And, correct me if I'm wrong, but isn't the X1->X2+X3->x4 series arrangement the more commonly used one for residential supplies?

 

[Besoeker]

State of the art!

And straight from the Ark.