Why is residential wiring known as single phase?

[mivey]

Says who? You are confusing a common node with a common reference point for all voltages.

Sez me.

This is wrong and professionally dishonest.

It really is a big conspiracy. Not sure how you found out but there is a lot riding on the outcome. Empires may crumble, cities may lie in ruins, Oreos will no longer have the creamy center. Now we'll have to re-work the strategy at the secret meeting tonight.

 

[mivey]

Terms used by technical people within their genre are called Jargon and are often inaccurate.

Wikipedia is not exactly a technical reference. I think of it more as a drive-by knowledge dump. Plenty of trash to sort through there.

Again, in response to your talking about using one voltage in two ways at the same time.

Except I wasn't at that time.

It strung back to here:

Bottom line with only the two ends of the secondary coil A & B. They can dual trace +240V<0 in one direction and -240<180 in the other direction. Therefore AB is 180 degrees out of phase with BA.

After all, if Mivey can excuse referencing one direction when measuring AN and reversing direction then I can reverse my reference frame to measure BA to get the above.

"only the two ends": Two terminal source

"They can dual trace +240V<0 in one direction and -240<180 in the other...": Dual trace = two ways at the same time

It would really help if you would keep up with the strings you are involved in.

Didn't claim they were. Suggested you expand them.

To what end?

Since you need help on this. http://en.wikipedia.org/wiki/Skin_effect

Hanging your hat on a knowledge dump site? I suggest you spend some time at a university library or take some courses instead of digging through the Wiki-trash (not dissing this particular article as I have not read it but I have found you have to take Wiki with a grain of salt).

Why the primary side? Why not the secondary side where all the debate is? Why sidetrack the discussion?

Consider the dual bushing single-phase transformer. Would you not make the argument that the voltages on the primary ends are the same as the voltages on the secondary ends (scaled, of course)? If it is a line-line short on the primary...

What would you call connecting A to a point half way between A and N? Halfway between N and B? To B?

Foolish, ignorant, dangerous...

Your primary short is of course the obvious phase-to-phase short but has nothing to do with the secondary. Any such connections on the secondary are a simple shorted coil. We often jokingly call the heaters.

Are you saying the substation transformer does not have a coil that connects to the distribution primary feeder?

 

[mivey]

"my good graces" and whatever the local going rate is will only get you a cup of Starbucks, but I genuinely appreciate it.

Then you are a step above me, as mine will only get you one at Waffle-House.

 

[rattus]

SNIPERS:

SNIPERS:

Says who? You are confusing a common node with a common reference point for all voltages. This is wrong and professionally dishonest.

SNIPERS! TAKE COVER!

 

[jim dungar]

Is that all? Then how about a quote from an authoritative reference:

How about one that deals with the output of a 'utility transformer' and not a circuit.
In case you missed it Vbn=-Vnb.

 

[jim dungar]

Doesn't matter Jim.

Typical of your participation - ignore the details, just acknowledge what you want to hear.

The rectifier circuit works because of the connection of the diodes and the reference point used for that circuit. It does not prove anything about the 'utility transformer output'.

I have consistently used your references for analyzing the transformer outputs, such as your choiec of assigning polarity dots. But that led to your current directions being out of phase with the voltages, yet Besoeker says they should be in phase. evidently you have made a wrong choice. Besoeker says, the independent transformer output V12 is in phase with with the independent output V34 or else they could not be connected in parallel. Using your reference terminals of X1 and X3, the waveforms of the two independent outputs are identical. Connect the two voltages in series and then you change your reference terminals, when will you maintain some consistency?
The outputs haven't changed, the only difference is how they are used in your circuit.

 

[jim dungar]

Has nothing to do with an oscilloscope. To compare voltages, we have to have a common reference. We all know this.

Rattus gave us his view of a common reference, the polarity dots of the transformer. After all these are what we use when wiring delta and wye configurations.

 

[mivey]

ignore the details, just acknowledge what you want to hear.

Speaking of which:

How about one that deals with the output of a 'utility transformer' and not a circuit.

Are you now saying a single-phase utility transformer output can't feed the terminals of entry for a single-phase circuit? :roll:

 

[mivey]

Rattus gave us his view of a common reference, the polarity dots of the transformer. After all these are what we use when wiring delta and wye configurations.

Again, you confuse polarity with positive direction. Again, they are not the same thing.

 

[jim dungar]

Again, you confuse polarity with positive direction. Again, they are not the same thing.

Assigning a reference point has nothing to do with assigning a positive direction. Rattus could just as easily have followed your lead and chosen away from node N but he didn't. Athough, that still would not have changed Besoeker's assertment that V12 and V34 must be in series because they can be paralleled.

 

[jim dungar]

Speaking of which:

Are you now saying a single-phase utility transformer output can't feed the terminals of entry for a single-phase circuit? :roll:

No.
For analysis purposes a circuit can be considered to be fed by a black box, didn't you know that?
And in case you also forgot, V1@0? = -V1@180?.

 

[rattus]

Typical of your participation - ignore the details, just acknowledge what you want to hear.

The rectifier circuit works because of the connection of the diodes and the reference point used for that circuit. It does not prove anything about the 'utility transformer output'.

I have consistently used your references for analyzing the transformer outputs, such as your choiec of assigning polarity dots. But that led to your current directions being out of phase with the voltages, yet Besoeker says they should be in phase. evidently you have made a wrong choice. Besoeker says, the independent transformer output V12 is in phase with with the independent output V34 or else they could not be connected in parallel. Using your reference terminals of X1 and X3, the waveforms of the two independent outputs are identical. Connect the two voltages in series and then you change your reference terminals, when will you maintain some consistency?
The outputs haven't changed, the only difference is how they are used in your circuit.

I agree with you that Vx1x2 and Vx3x4 are in phase, but in Bes's rectifier circuit we need to establish values V1n (L1) and V2n (L2). Then

V1n = Vx1x2 and

V2n = Vx4x3 not Vx3X4.

In order to perform mesh and node analyses, we must label the nodes correctly, that is with magnitude and phase angle, and we must refer the voltages to a reference. N is the obvious choice here.

I don't think it matters that the sources represent a transformer. In setting up a circuit for analysis we use equivalents. We could include a transformer equivalent circuit if actual performance is an issue, but the issue here is about V1n and V2n. Are they in or out of phase?

As for the dots, I prefer to think that they indicate that voltages at those nodes are in phase rather than antiphase.

 

[gar]

120223-2106 EST

jim:

If we use the conventional usage of the labeling of X1 and X2 being one secondary coil with X2 having an associated dot, and the other other coil being X3 and X4 with 4 having the dot, then connect X1 to X3. What is the voltage difference between X2 and X4? In turn is V_X2-X1 in-phase or 180 degrees out of phase with V_X4-X3?

If the voltage difference is 0, then can X2 and X4 be connected together without sparks?

Next connect X2 to X3, what is the voltage difference between X1 and X4? Can X1 be connected to X4 without sparks?

What is the phase relationship between V_X1-X2 and V_X4-X3?


For all those that are hung up on a continuous secondary coil with a center tap being one continuous thing I can make a transformer with a continuous winding, meaning I do not cut the wire in the middle while winding the coil, that puts X1 in-phase with X4 and thus I can connect X1 to X4 with no sparks. Also now the center tap voltage is not midway between X1 and X4.

.

 

[Besoeker]

I apologize for missing it.

Help me with this one - do you assert that the load characteristics alter the transformer secondary voltages?

I did not assert that.
I commented that, with resistive load as shown in my diagram, voltages and currents are in phase.
This is the case regardless of whether you have diodes in the output.

I apologize I haven't found your original response to 888.

It was a simple qualification to your initial statement.

 

[Besoeker]

I apologize for missing it.

Help me with this one - do you assert that the load characteristics alter the transformer secondary voltages?

No, I didn't and don't assert that.
I commented that, with resistive load as shown in my diagram, voltages and currents are in phase.
This is the case regardless of whether you have diodes in the output.

I apologize I haven't found your original response to 888.

It was a simple qualification to your initial statement.

 

[rbalex]

No, I didn't and don't assert that.
I commented that, with resistive load as shown in my diagram, voltages and currents are in phase.
This is the case regardless of whether you have diodes in the output.


It was a simple qualification to your initial statement.

Then are you saying the load's characteristics are irrelevant to the phase of transformer secondary voltages?
And I'm still interested in your response to 888 - I can't find it

 

[Besoeker]

Just a note in passing.

I've posted diagrams, clips from actual drawings of circuits I've designed, drawings of power circuits we've manufactured, photographs of things we've made.
Although I'm the final arbiter on commercial and technical matters, it's very much a team effort. I have a chief project engineer and a workshop foreman both of whom have been with me for decades. The guy in charge of service is the new boy on the block. Just twelve years in.
And my sweet wife joined the motley crew a bit over ten years ago as a temp when my previous side kick and PA went off on maternity leave.

There are two points to this post.

First is that I have presented real drawings and pictures of real things that we have made in support of my points about the not single phase argument. As far as I can tell, not a single other poster has reciprocated. We have all talked the talk. Myself included. I've also had to walk the walk. Commit both technically and commercially. Yes, it's the day job. And it can be stressful. Actually is.

The second, and much more important point, is that the pics that I've posted of what we make is what my guys make. I'm lucky to have the team that we do.
And that they work together well.

 

[rattus]

Here we have Bes's full wave rectifier drawn with voltage sources replaces the transformers. Each source represents a leg of the transformer, and the various nodes are labeled with transformer nomenclature and polarity dots. These dots indicate an in phase condition for the nodes so marked.

Then at wt = 0, V1 goes positive, and D1 conducts. At wt = pi, V2 goes positive and D2 conducts, and so forth, on and on and on.

 

[rattus]

Duplicate

 

[Ponchik]

There are two ways to handle this.

For me I just accept 'because we do' Me Too.

The other way takes 600 forum posts. we are on 1300 now :lol::lol:


Good luck!

i made the 1300th post. do i get a prize. I think this is the longest post. OP see what you have done. LOL.