Why is residential wiring known as single phase?
- Thread starter TimWA
- Start date
- Status
mivey
Senior Member
First, a winding alone has no phase. It is the waveform in the winding which exhibits a phase. Even so, I have no disagreement with the general statement that the "windings are in phase" if they can be paralleled without the fireworks. What we mean is that the voltages are in phase. Let's call that an absolute based on the physical.
That however is not the only truth that is present. There is also the truth that if the windings are connected in fireworks mode that the voltages are not connected in phase. Let's call that another absolute based on the physical.
To get to the finish line before we all die of old age, I believe you are proposing that if X1-X2 can be paralleled with X3-X4 then they are connected in phase. I agree with that. It would seem your next logical statement would be that if X1-X2 and X3-X4 are in phase when paralleled then they must be in phase when in series like we see with X1-X2&X3-X4. I would also agree with that. I don't think any of us here are disputing how transformers are connected and how they work.
What I have said is that while it is a real-world fact that X1-X2 is in phase with X3-X4, another real-world fact also exists and that fact is that X1-X2 is not in phase with X4-X3. Both are facts and both are based on the fact that the conditions of "in phase" or "not in phase" are relative.
If my short-cut through the infield has sidetracked your process then put us back on track and I'll wait to see where you are headed. But I'm starting count how many useful years I have left. I guess you could just wait and out-live me and "win" by default.
mivey
Senior Member
Well you can certainly remove it. But once you remove it you no longer have the same two functions and would need to replace "=" with "≠", at least in our world.
The problem rbalex is having is that he is trying to say that when you have waveforms with symmetry that the naming conventions use that as a flag to use a lower-order name. Unfortunately, he is off in his own little world trying to re-write the meaning of "phase" and "in-phase" instead of just using a more appropriate term like symmetry.
I do not have a phrase worked out using symmetry but something on that order should work for the majority of systems. I really don't see it any more functional than using Jim's "line-line" method and I think Jim's is much simpler and easier to explain.
Creating bogus math terms and re-defining existing math terms sure isn't the way to go, IMO.
T
T.M.Haja Sahib
Guest
You mean V12=V1n+Vn1 at any instant is wrong?
T
T.M.Haja Sahib
Guest
Yes.It is my humble opinion that because of your that misunderstanding,you do not admit that 120/240v supply is a single phase supply!
- Location
- Mission Viejo, CA
- Occupation
- Professional Electrical Engineer
Possibly, but only if you accept trigomometric identities are real - they appear to be beyond mivey's comprehension.
mivey
Senior Member
Feel like a bigger man now?
- Location
- Wisconsin
- Occupation
- PE (Retired) - Power Systems
Wow what a shock X<>-X.
Doesn't really answer the question. Question was not about trig. I learned in HS that you can manipulate both sides of an equation equally, but I didn't learn that you could invert only one side. How do you do it?
All those math courses, wasted!
- Location
- Mission Viejo, CA
- Occupation
- Professional Electrical Engineer
Do you accept trig identities as valid?
Dancing With the Stars?
Dancing With the Stars?
The question was about algebra, not trig.
Dancing With the Stars?
The question was about algebra, not trig.
mivey
Senior Member
And the shocking lesson that there is more than one truth. So I guess since it really is that simple then you would agree that we have these two physical truths:
1) The voltage from X1 to X2 and the voltage from X3 to X4 have a 0? displacement between them
2) The voltage from X2 to X1 and the voltage from X3 to X4 have a 180? displacement between them
T
T.M.Haja Sahib
Guest
So what?
I am sure that is a typo, but V1n + Vn1 = 0, V1n + Vn2 = V12 = V1n - V2n
I meant that V1n and V2n drive the split phase loads.
mivey
Senior Member
So it is a physical fact, not just a mathematical equivalent, that we have 0? voltages and 180? voltages across the windings. The difference is which reference frame you use, but both are physical realities.
In other words, we have both in-phase voltages and phase-opposed voltages at the transformer.
- Location
- Mission Viejo, CA
- Occupation
- Professional Electrical Engineer
The solution is beyond the scope of high school algebra. However, if you remember back far enough you should remember that for simple equations only one side of the equation should be manipulated properly. Manipulating both sides was a "short-cut" until you resolve (or isolate) the final variable. But the principal you mentioned was still valid.
Last edited:
Rick Christopherson
Senior Member
I'm kind of confused why you are asking this. It is actually the founding basis for your argument. This is the mathematical principle that permits you to take a physical inversion and turn it into a mathematical phase shift. If you reject this mathematical equality, then you can't even claim that you have an "apparent" phase shift, let alone a "real" one.
Unless of course this is a set-up question hoping to dupe someone into an argument that you have already walked away from several pages ago.
Yeah! I know you well enough to recognize a set-up question.
So I guess I need to go back to asking why you refuse to answer the question I already posed to you ages ago?Did you think I walked away from this discussion, so it was safe to head back down that road? :dunce:
jumper
Senior Member
- Location
- 3 Hr 2 Min from Winged Horses
Works for me.
T
T.M.Haja Sahib
Guest
But it is not unique:if 120/240v supply has it,120V supply also does.Correct?
jumper
Senior Member
- Location
- 3 Hr 2 Min from Winged Horses
made it to 1000 posts.:thumbsup:
- Status