Why is residential wiring known as single phase?

[Besoeker]

120/240 is the IEEE/ANSI recognized methodology. It better not be misleading.

I've seen plenty of things written in regulations that were far from clear. I'm sure you have too.

 

[Besoeker]

You need to go back and read the very first post, it clearly says "same utility transformer (ie. one winding)".

Your post #979:

If we follow the industry standard interconnections, they can be interconnected as paralleled with X1&X3~X2&X4, series with X1~X2&X3~X4

If it was one winding, you wouldn't have the connection permutations you are suggesting.

 

[Besoeker]

Bingo!

synchronism: The state where connected alternating-current systems, machines, or a combination operate at the same frequency and where the phase angle displacement between voltages in them are constant, or vary about a steady and stable average value.

 

[rbalex]

Bingo!

As I said, I had to post it for the professional honesty.

But to clarify things, would you say that it's OK to "... connect[-] alternating-current systems, machines, or a combination operate[d] at the same frequency and where the phase angle displacement between voltages in them are constant, or vary about a steady and stable average value" but don't have equal voltage magnitudes?

Apparently, "in-phase" and "in-sync" are colloquially synonymous in your branch of the industry. They aren't in mine - we make a distinction and it happens to be consistent with the question “Why is residential wiring known as single phase?” We may use instruments to confirm synchronism – but not to define it or phase.

 

[rattus]

Colloquial Defintion of In Phase:

Colloquial Defintion of In Phase:

In Phase: *The case where the positive peaks of sine or cosine waves of the same frequency occur at the same time. Then the troughs would also occur at the same time. No need for page after page of definitions. Nuf sed!

Amplitude is not a factor, but polarity is.

*Paraphrased from Tang, Alternating Current Circuits.

 

[Besoeker]

As I said, I had to post it for the professional honesty.

Kudos to you for that.

But to clarify things, would you say that it's OK to "... connect[-] alternating-current systems, machines, or a combination operate[d] at the same frequency and where the phase angle displacement between voltages in them are constant, or vary about a steady and stable average value" but don't have equal voltage magnitudes?

No. Or at least not without qualification about the differences in magnitude and phase.

Apparently, "in-phase" and "in-sync" are colloquially synonymous in your branch of the industry.

Not in mine.

 

[mivey]

Nevertheless the IEEE Std. 100 definition as cited is accurate and I believe both it and the source is still authoritative with respect to Instrumentation and Measurement.

Authoritative as it is, it still does not say what you claim. The phase is described as being the fractional portion of the period, not only part of the period. You have made an interpretation that does not agree with the rest of the industry members. They read the same definition, and then proceed to define "in-phase" in the way I have shown from many sources. If the industry sees phase and the subsequent definition of "in-phase" different from you, then it is obvious that the industry is not in agreement with your interpretation.

I'm not saying you have to agree with our industry, just stop quoting what we use and pretending like you are somehow in agreement with the "authoritative" reference. The people who write and teach these the reference obviously are not in agreement with you. I'm all for the rebel thing, but don't rebel and claim you are part of the mainstream.

 

[mivey]

Seriously, we have been wrestling with a center tapped transformer output being; (2) voltages in-phase or (2) voltages out-of phase.

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

3.423 single-phase circuit: An alternating-current circuit consisting of two or three intentionally interrelated conductors that enter (or leave) a delimited region at two or three terminals of entry. If the circuit consists of two conductors, it is intended to be so energized that, in the steady state, the voltage between the two terminals of entry is an alternating voltage. If the circuit consists of three conductors, it is intended to be so energized that, in steady state, the alternating voltages between any two terminals of entry have the same period and are in phase or in phase opposition.

 

[mivey]

Did you read my response to your follow-up (Post 1221)? I did say the currents don't need to be - I didn't say they weren't; in fact, they probably are. However, the secondary current's behavior isn't what determines whether the transformer secondary voltages have the same characteristic phase and the phase characteristic of transformer secondary voltages isn't dependent on the are measurement technique. If the transformer secondary voltages have the same characteristic phase (which they do - which, in fact, they must) it's quite reasonable to describe the system as single-phase (which it is). QED.

Please review post 888 before we go another round. The definition of phase in that Post was actually supplied by rattus but, for the purposes of this discussion, it is compatible with the IEEE Std. 100 definition above.

Please quote the definition for "characteristic phase" from IEEE Std 100.

PS: don't bother looking 'cause it aint there.

 

[mivey]

We must measure all voltages with respect to a common reference

Where is that written?
...
Oh, that's right. Your oscilloscope is limited in its capabilities.

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

 

[mivey]

I appreciate you posted definiton of synchronous that are compatible with Post 888 - even if it had to come from a "computing" source.

Now that's funny. Dissing the poor "computing" source when you have made up "characteristic phase" on your own with no source at all.

 

[bob]

I have just received an email from the President of the International Society of Internet Providers. He has advised me that all of the computers making up the Internet are grossly overloaded, circuits are heating up, operators are passing out, repairmen are going on strike, internet speed is crawling(to me that nothing new) all because of the 23,000 nosey people that have had to view this post. He has asked that some agreement be reached to save the world. If the Internet fails you know who Russia, China N. Korea. Iraq and Iran will blame. Its going to be Iwire because he said

There are two ways to handle this.

For me I just accept 'because we do'

The other way takes 600 forum posts.

600 posts!!!!!!!! You screwed the pooch on that estimate.
So the President has suggested that Jim, K8MHZ, Joe, Besoeker, rbalex, mivey, Rick, Pfalcon and anyone
else take it outside and settle the issue.
The last one standing will make a final post for all to read.

 

[Gac66610]

:lol: good idea :thumbsup:

 

[Rick Christopherson]

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

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

 

[rbalex]

No. Or at least not without qualification about the differences in magnitude and phase.

I may have "cheated" on you; I revised the question to only include magnitude since polarity is implied by "phase angle". Magnitude seems to elude consideration - even though we both know it's a critical consideration in most cases. But I'm pretty certain your answer would have been the same.

Not in mine.

Excellent! Then we have synchronism out of the way, so let's get back to phase - where neither magnitude nor polarity are necessary to consider. Would you respond directly to Post 1241?

 

[pfalcon]

Post 1214: Thanks Besoeker. That technique I can see.

Why bother with a definition of phase ...

And with that response, ...

Sorry. Did sound bad. I'm leaving the math and phase definitions to you and Rattus/Mivey. Taking a different tack.

I said I used "in phase" like our industry does. You responded that it was technically incorrect, industry or not, and did not apply to a technical discussion. I replied that the sources were mainly used in the technical arena. In fact, most are used in teaching and how much more technical does it get than that?

A transformer supplying a 3-wire distribution system has a single-phase input (primary) winding. The output (secondary) winding is center-tapped and the center tap connected to a grounded neutral. This 3-wire system is common in countries with a standard phase-neutral voltage of 120 V. In this case, the transformer voltage is 120 V on either side of the center tap, giving 240 V between the two live conductors, shown as V1 and V2 in Fig. 1. The two outputs are properly called "legs", not "phases".

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

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

Except I wasn't at that time.

Weren't my experiments. These were in the 1860's.

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

Just more electrical theory you don't understand. ...

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

What would you call two ungrounded conductors on the primary side being shorted?

Why the primary side? Why not the secondary side where all the debate is? Why sidetrack the discussion? What would you call connecting A to a point half way between A and N? Halfway between N and B? To B? 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.

... Can you connect the two outer ends of a center tapped transformer together and have essentially no circulating current, or do you get big sparks? No sparks and the coils are "in-phase". No meters, no scopes, just a simple experiment.

Connecting the two ends is how we get a light bulb or a heater. AC or DC makes no difference. You have a potential difference between the points. It doesn't matter which two points on the coil you short. It doesn't have to cross the neutral to spark. They don't have to be out of phase. Just at different potentials.

 

[rattus]

I may have "cheated" on you; I revised the question to only include magnitude since polarity is implied by "phase angle". Magnitude seems to elude consideration - even though we both know it's a critical consideration in most cases. But I'm pretty certain your answer would have been the same.
Excellent! Then we have synchronism out of the way, so let's get back to phase - where neither magnitude nor polarity are necessary to consider. Would you respond directly to Post 1241?

But polarity is necessary, because in a word, phase difference is the difference between POSITIVE peaks. For example,

phi1 = (wt)
phi2 = (wt + 180)

The phase angles are 0 and 180.

The difference is 180 degrees, pure and simple, no ifs, ands, or buts about it. It is what it is and always will be!

 

[rbalex]

...
Sorry. Did sound bad...

With that, you wormed your way back into my good graces :thumbsup: - Of course, "my good graces" and whatever the local going rate is will only get you a cup of Starbucks, but I genuinely appreciate it.

 

[Besoeker]

Would you respond directly to Post 1241?

I did.
Post #1245.

 

[rbalex]

I did.
Post #1245.

I apologize for missing it.

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

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